Colorectal Surgery (Large Intestine, Rectal, Anal Canal, Colorectal Carcinoma) MCQs

Surgery · 200 free questions with answers & explanations.

1. A 65-year-old man presents with a change in bowel habit and fresh rectal bleeding. Colonoscopy reveals an annular carcinoma of the sigmoid colon. CEA is 12 ng/mL. CT staging shows the tumour limited to the bowel wall with no nodes involved (T2N0M0). What is the definitive treatment?
2. A 70-year-old woman presents with a 4 cm carcinoma in the mid-rectum (8 cm from the anal verge). MRI shows involvement of the mesorectal fascia (threatened circumferential resection margin). The most appropriate initial management is:
3. A 40-year-old man presents with bright red blood per rectum, severe perianal pain, and a palpable tender lump at the anal verge. The lump has a dusky appearance. The most likely diagnosis is:
4. A 55-year-old man undergoes proctoscopy and is found to have anal squamous cell carcinoma 3 cm in diameter confined to the anal canal without lymph node involvement. The preferred treatment is:
5. A 58-year-old man has a rectal cancer at 7 cm from the anal verge. MRI shows T3N1 disease with threatened circumferential resection margin (CRM <1 mm). The optimal management sequence is:
6. A patient undergoes colonoscopy and is found to have more than 100 colonic polyps. Genetic testing reveals a germline APC mutation. This patient is at highest risk for which extra-colonic manifestation?
7. During anterior resection for rectal cancer, which nerve injury is most likely to cause bladder dysfunction (urinary retention and loss of ejaculation) if the pelvic autonomic nerves are not preserved?
8. A 45-year-old woman presents with chronic proctalgia and painful defecation. Examination reveals an anal fissure in the posterior midline with a sentinel skin tag. First-line medical therapy (topical GTN) has failed for 8 weeks. The most appropriate next intervention is:
9. Lynch syndrome (hereditary non-polyposis colorectal cancer, HNPCC) is caused by germline mutations in mismatch repair (MMR) genes. Which gene mutation confers the highest lifetime risk of endometrial cancer, approaching 40-60%?
10. A 58-year-old man with T3N1M0 rectal carcinoma (mid-rectum, 8 cm from anal verge) undergoes pre-operative long-course chemoradiotherapy followed by low anterior resection with total mesorectal excision (TME). The key oncological principle behind TME is:
11. Lynch syndrome (HNPCC) is caused by germline mutations in mismatch repair (MMR) genes. Which gene mutation is associated with the Muir-Torre variant that includes sebaceous skin tumours and keratoacanthomas?
12. A 44-year-old woman presents with rectal bleeding. Sigmoidoscopy reveals a 3 cm lesion at the dentate line. Biopsy shows squamous cell carcinoma. The current first-line treatment for carcinoma of the anal canal (not anal margin) is:
13. The circumferential resection margin (CRM) status reported in rectal cancer histopathology is defined as positive when tumour is within what distance from the cut circumferential margin, and what is its clinical significance?
14. A 55-year-old man is found to have a 3 cm solitary hepatic metastasis from colorectal cancer, confirmed on PET-CT with no other distant disease. His primary tumour has been resected with clear margins. What is the most appropriate management of the liver metastasis?
15. A 55-year-old man has a 5 cm rectal cancer located 8 cm from the anal verge on rigid sigmoidoscopy. MRI pelvis shows T3 N1 disease with a circumferential resection margin (CRM) of 1.5 mm. The most appropriate initial management sequence is:
16. A 48-year-old woman is found to have Lynch syndrome (MLH1 germline mutation) after colorectal cancer diagnosis. Her 22-year-old daughter undergoes colonoscopy and is found to have multiple small tubular adenomas. The current recommendation for colonoscopic surveillance in confirmed Lynch syndrome carriers (gene mutation positive) who are otherwise normal is:
17. A 62-year-old man undergoes anterior resection for rectal cancer. Six months later, follow-up CT shows 3 synchronous liver metastases: two in segments VI/VII (largest 2.8 cm) and one in segment IV (1.5 cm). CEA is 18 ng/mL. The oncology team discusses colorectal liver metastases (CRLM) resectability. Which factor would definitively render this patient UNRESECTABLE by international consensus criteria?
18. A 45-year-old man presents with a 4 cm squamous cell carcinoma of the anal canal (T2 N0 M0). The primary treatment of choice and the rationale for avoiding abdominoperineal resection (APR) is based on which landmark trial?
19. A 60-year-old man with T3N1M0 rectal carcinoma 6 cm from the anal verge undergoes long-course chemoradiotherapy (CRT). After restaging MRI, no residual tumor is seen. He wants to avoid permanent colostomy. What is the most appropriate next step according to current evidence?
20. In the total mesorectal excision (TME) technique for rectal cancer, which fascial plane must be maintained to achieve an oncologically adequate resection with minimal autonomic nerve damage?
21. A 45-year-old patient with Lynch syndrome (MLH1 mutation) is found to have a 2 cm sigmoid colon cancer and a synchronous 1 cm ascending colon adenoma with high-grade dysplasia. What is the most appropriate surgical strategy?
22. In the Dukes classification of colorectal carcinoma, which modification correctly describes Dukes C2 stage?
23. A patient presents with Ogilvie's syndrome (acute colonic pseudo-obstruction) after a major orthopedic surgery. The cecal diameter on CT is 11 cm. Initial conservative management fails after 48 hours. What is the next best step?
24. A 62-year-old man undergoes anterior resection for a rectal cancer at 8 cm from the anal verge. Total mesorectal excision (TME) is performed. Which anatomical landmark defines the distal boundary of the mesorectum and guides the distal extent of sharp dissection during TME?
25. Which molecular pathway, characterised by widespread microsatellite instability (MSI-H) due to deficient mismatch repair (dMMR), confers a paradoxically better prognosis in stage II colorectal cancer but predicts resistance to standard 5-FU-based adjuvant chemotherapy?
26. A 70-year-old man presents with anal canal squamous cell carcinoma (T2N0) confirmed on biopsy. What is the standard curative treatment as established by the Nigro protocol?
27. In Lynch syndrome (hereditary non-polyposis colorectal cancer), a pathogenic germline mutation in which gene creates a DNA mismatch repair deficiency and confers the highest lifetime risk of colorectal cancer?
28. A patient with familial adenomatous polyposis (FAP) is undergoing risk reduction surgery. Compared to total proctocolectomy with ileal pouch-anal anastomosis (IPAA), restorative proctocolectomy with IPAA is preferred because FAP patients harbour a particular risk in the retained rectal stump. What is the approximate lifetime risk of developing rectal cancer in an FAP patient with an intact retained rectum?
29. A 65-year-old man with rectal adenocarcinoma 5 cm from the anal verge undergoes pre-treatment MRI. MRI shows the tumor invades through the muscularis propria but is 4 mm from the mesorectal fascia (circumferential resection margin). What is the most appropriate neoadjuvant strategy per current ESMO guidelines?
30. Hartmann's procedure is performed for perforated sigmoid diverticulitis with feculent peritonitis. Six months later, the patient desires reversal. What is the main technical challenge of Hartmann's reversal that results in a 30–50% non-reversal rate?
31. Which of the following Lynch syndrome (HNPCC) genes, when mutated, accounts for the highest proportion of Lynch syndrome cases?
32. Anal squamous cell carcinoma is primarily treated with the Nigro protocol (chemoradiotherapy). What is the chemotherapy backbone of the original Nigro protocol?
33. A 38-year-old with FAP (APC mutation) undergoes proctocolectomy. Postoperatively, he develops a 3-cm mesenteric desmoid tumor causing ureteral obstruction. Which of the following best describes the biological behavior of desmoid tumors in FAP?
34. A 55-year-old man has a 4 cm rectal adenocarcinoma at 7 cm from the anal verge on rigid sigmoidoscopy, staged as cT3N1M0. According to MERCURY trial-based principles, the MRI report shows the circumferential resection margin (CRM) involvement is predicted. What is the preferred neoadjuvant strategy?
35. During anterior resection for rectal cancer at 12 cm from the anal verge, the surgeon performs total mesorectal excision (TME). What is the MOST important surgical plane in TME that determines local recurrence rates?
36. Microsatellite instability (MSI-H) in colorectal carcinoma has which of the following clinical-pathological implications for treatment decision-making?
37. A 32-year-old patient with familial adenomatous polyposis (FAP) and a desmoid tumor at the root of the mesentery undergoes total proctocolectomy. Which genetic alteration is associated with desmoid tumor formation in FAP and affects surgical strategy?
38. For a T1 N0 rectal adenocarcinoma at 3 cm from the anal verge, confined to the submucosa (sm1), which local excision technique and oncological criterion determine adequacy of treatment without radical resection?
39. A 58-year-old man with locally advanced rectal cancer (T3N1M0) undergoes long-course neoadjuvant chemoradiotherapy. Post-treatment MRI at 12 weeks shows complete clinical response (cCR). According to the Brazilian 'Watch and Wait' protocol (Habr-Gama), which strategy is recommended?
40. A 72-year-old woman undergoes right hemicolectomy for stage IIIB (T3N2a) colon cancer. Microsatellite instability (MSI) testing on the surgical specimen reveals high-level MSI (MSI-H). Which adjuvant chemotherapy decision is most directly influenced by this finding?
41. A 44-year-old man with familial adenomatous polyposis (FAP) has undergone colectomy with ileorectal anastomosis (IRA) at age 22. He now presents with 8 rectal polyps ranging from 5-15 mm with increasing dysplasia. KRAS mutation analysis of one polyp is positive. What is the most appropriate surgical management?
42. According to the Dukes and TNM staging correlation for rectal carcinoma, which statement correctly pairs TNM stage with Dukes classification and corresponding 5-year survival?
43. A 58-year-old man with rectal cancer at 7 cm from anal verge undergoes staging MRI. Tumor is staged mrT3c N1 (extramural invasion 6 mm, CRM negative). According to current MERCURY study-based criteria, the optimal neoadjuvant strategy is:
44. A 45-year-old patient with Lynch syndrome (MLH1 germline mutation) undergoes colonoscopy revealing a 2 cm adenomatous polyp in the ascending colon. After polypectomy, surveillance colonoscopy interval per current USMSTF/BSG guidelines should be:
45. A patient with a T2N0 mid-rectal cancer (8 cm from anal verge) is considered for transanal excision versus radical resection. According to ACOSOG Z6041 trial findings, which feature MOST strongly predicts residual or recurrent disease after local excision with chemoradiation?
46. During laparoscopic left hemicolectomy for sigmoid colon cancer, the surgeon identifies the inferior mesenteric artery (IMA). To perform a high ligation of IMA while preserving autonomic function, the dissection should be medial to:
47. A 55-year-old patient with stage IV rectal cancer (synchronous liver metastases, 3 bilobar, technically resectable) is evaluated for treatment strategy. Which management approach is supported by current ESMO guidelines for potentially resectable synchronous colorectal liver metastases?
48. A 58-year-old man has a rectal cancer at 7 cm from the anal verge on rigid sigmoidoscopy. MRI pelvis shows T3N1 disease with circumferential resection margin (CRM) predicted to be 1 mm (threatened). According to current UK/NICE and ESMO guidelines, the most appropriate management sequence is:
49. A patient with Stage III colon cancer (pT3N2aM0) completes curative resection. Microsatellite instability (MSI) testing shows MSI-High status. Regarding adjuvant chemotherapy, which statement is most accurate based on current evidence?
50. During laparoscopic anterior resection for a mid-rectal cancer, the sympathetic hypogastric plexus is at risk. At what anatomical level does the superior hypogastric plexus divide into right and left hypogastric nerves?
51. A 45-year-old man presents with anal canal squamous cell carcinoma measuring 4 cm (T2N0M0) confirmed on MRI. He has no distant metastases. The standard of care treatment is:
52. A 62-year-old woman with familial adenomatous polyposis (FAP) has undergone colectomy with ileal pouch-anal anastomosis (IPAA). Annual surveillance of the pouch reveals a 1.2 cm tubulovillous adenoma in the ileal pouch. The molecular basis for ongoing adenoma formation in the ileal pouch in FAP patients is:
53. In transanal total mesorectal excision (TaTME) for rectal cancer, the 'holy plane' of sharp dissection is between:
54. A 62-year-old man presents with rectal bleeding and colonoscopy reveals a polypoid lesion at 6 cm from the anal verge. Biopsy shows T1 rectal adenocarcinoma. MRI pelvis confirms invasion confined to submucosa (sm1), negative circumferential resection margin (CRM) of 3 mm, no lymphovascular invasion, and well-differentiated histology. The preferred treatment is:
55. According to the Amsterdam II criteria for hereditary non-polyposis colorectal cancer (Lynch syndrome), which of the following is NOT required?
56. A patient with T3N1M0 (Stage IIIB) mid-rectal adenocarcinoma undergoes long-course chemoradiation (45–50 Gy + 5-FU) followed by total mesorectal excision. Pathology shows ypT0N0 (complete pathological response). According to current evidence and 'Watch-and-Wait' protocols, which assessment tool is used to determine eligibility for non-operative management of near-complete clinical response?
57. In the Dukes-Astler-Coller (MAC) classification of colorectal cancer, a tumor that penetrates through the bowel wall into pericolic fat and has positive regional lymph nodes corresponds to:
58. A 65-year-old man with rectal cancer 4 cm from the anal verge is staged T3N1M0 on MRI. He receives long-course chemoradiotherapy followed by total mesorectal excision (TME) 8 weeks later. Histology shows ypT0N0M0 (complete pathological response). Per PROSPECT trial results, which neoadjuvant regimen in which subgroup showed equivalent outcomes allowing radiotherapy omission?
59. A 50-year-old woman with Lynch syndrome (MLH1 germline mutation) undergoes colonoscopy revealing a 3 cm right-sided colon cancer and 2 synchronous tubular adenomas in the left colon. What is the most appropriate surgical strategy?
60. A 72-year-old man presents with acute left-sided colonic obstruction. CT scan shows an obstructing sigmoid carcinoma with no free perforation. He has no peritonitis and is hemodynamically stable. According to current ESGE/ESCP guidelines, what is the preferred initial management?
61. In transanal total mesorectal excision (TaTME), compared to laparoscopic TME, which specific anatomical plane is approached from the perineal route to avoid the most critical complication of urethral injury?
62. A 40-year-old man with squamous cell carcinoma of the anal canal (T2N0M0) is staged by MRI. Per current ESMO guidelines, what is the primary treatment modality?
63. A 60-year-old patient with a T3N1M0 rectal carcinoma located 6 cm from the anal verge is planned for curative resection. MRI shows threatened circumferential resection margin (CRM ≤ 1 mm). According to current guidelines (ESMO/NCCN), what is the optimal pre-operative treatment?
64. A 65-year-old patient with MSI-H (mismatch repair deficient) colorectal cancer metastatic to the liver presents for first-line treatment. She has KRAS/NRAS/BRAF wild-type tumor. What is the most appropriate first-line systemic therapy?
65. A 58-year-old patient with a T2N0 rectal cancer at 4 cm from the anal verge is evaluated for sphincter preservation. Which anatomical landmark defines the distal margin required for adequate total mesorectal excision (TME)?
66. A Lynch syndrome patient (MLH1 mutation) is diagnosed with a 2.5 cm carcinoma in the ascending colon. She is 35 years old. What is the most appropriate surgical option and surveillance recommendation?
67. Which Dukes/TNM staging classification corresponds to a colorectal cancer invading through the muscularis propria into the pericolorectal tissues but not penetrating the peritoneum and with no nodal or distant metastasis?
68. A 62-year-old man with a cT3N1M0 mid-rectal adenocarcinoma (5 cm from anal verge, circumferential resection margin threatened on MRI) receives long-course chemoradiotherapy. He achieves clinical complete response at 12 weeks post-CRT reassessment. Which management strategy is supported by current evidence (based on the OPRA trial)?
69. During anterior resection for upper rectal carcinoma, the autonomic nerve supply to the bladder and sexual organs is at risk. Which specific structure, if damaged during dissection along the right pelvic sidewall, most commonly causes retrograde ejaculation in male patients?
70. A 45-year-old man with Lynch syndrome (MLH1 mutation) is diagnosed with synchronous right-sided colon cancer (caecum) and a polyp at the sigmoid colon that is not amenable to endoscopic resection. What is the most appropriate surgical strategy?
71. A 58-year-old woman presents with high-grade squamous intraepithelial lesion (HSIL) of the anal canal confirmed on HRA (high-resolution anoscopy) biopsy. Which of the following best describes the appropriate management according to current guidelines following the ANCHOR trial?
72. A 70-year-old man presents with acute left-sided colonic obstruction due to sigmoid carcinoma. CT shows no peritoneal disease or distant metastases. He is haemodynamically stable. Current evidence-based practice (endorsed by ESGE/ESMO guidelines) recommends which of the following as the preferred management?
73. A 62-year-old man has a T3N1M0 rectal adenocarcinoma at 6 cm from the anal verge. MRI shows threatened CRM. Which is the current standard neoadjuvant strategy before TME?
74. During total mesorectal excision (TME) for mid-rectal carcinoma, which anatomical landmark defines the posterior dissection plane that minimizes autonomic nerve injury?
75. Lynch syndrome (HNPCC) colorectal cancer is caused by germline mutations in which group of genes, and what is the characteristic histological feature of these tumors?
76. A 55-year-old man has an isolated synchronous liver metastasis (3 cm, segment VI) from a resected colon cancer (pT3N2 after curative right hemicolectomy). He has adequate hepatic reserve. Which is the most appropriate management strategy per current guidelines?
77. Anal squamous cell carcinoma: what is the current first-line treatment per Nigro protocol and subsequent modifications?
78. In total mesorectal excision (TME) for rectal cancer, the circumferential resection margin (CRM) is considered positive (predicting local recurrence) when the tumour is within what distance of the mesorectal fascia?
79. A 60-year-old man with a T3N1M0 mid-rectal cancer (6 cm from anal verge) on staging MRI. The MERCURY trial and current ESMO guidelines recommend which preoperative treatment strategy?
80. Regarding Lynch syndrome (HNPCC) colorectal cancer screening, which mismatch repair gene mutation is associated with the highest penetrance of colorectal cancer?
81. A patient with T2N0M0 rectal cancer (4 cm from anal verge) achieves a clinical complete response after long-course chemoradiation. The watch-and-wait (non-operative management) approach is most appropriate when which criterion is met?
82. Squamous cell carcinoma of the anal canal is primarily managed with which protocol, and what constitutes treatment failure at 26 weeks?
83. A 55-year-old patient with rectal cancer 5 cm from the anal verge has clinical staging T3N1M0. According to MERCURY study criteria, involvement of which structure on MRI mandates preoperative chemoradiotherapy to achieve R0 resection?
84. Lynch syndrome (HNPCC) is caused by germline mutations in DNA mismatch repair genes. Which clinical criterion in the revised Amsterdam II criteria distinguishes Lynch syndrome-associated colorectal cancer from sporadic cancer?
85. In Hartmann's procedure performed for obstructed sigmoid colon cancer, what defines the anatomical basis for the subsequent reversal procedure (Hartmann's reversal)?
86. Which classification system grades the quality of total mesorectal excision (TME) specimens and correlates directly with local recurrence risk in rectal cancer surgery?
87. A patient is found to have a 4 mm pedunculated polyp with high-grade dysplasia confined to the head, negative margins, no lymphovascular invasion, and no poorly differentiated component on polypectomy. What is the appropriate next management step per guidelines?
88. A 65-year-old man with a 4 cm rectal carcinoma 5 cm from the anal verge is staged T3 N1 M0 on MRI. The circumferential resection margin (CRM) on MRI is threatened (tumour within 1 mm of mesorectal fascia). According to current guidelines the optimal initial treatment is:
89. A patient undergoes anterior resection for rectal cancer with a colorectal anastomosis 7 cm from the anal verge. On postoperative day 5, CT shows a pericolic collection with air adjacent to the anastomosis, and the patient has a temperature of 38.8°C with mild peritonism. The defunctioning loop ileostomy is intact. What is the most appropriate next step?
90. A 45-year-old man with Lynch syndrome (MLH1 germline mutation confirmed) is diagnosed with a T2 N0 colon cancer in the splenic flexure. After completion of treatment, what is the recommended surveillance colonoscopy interval?
91. A 70-year-old man presents with severe haematochezia. Colonoscopy identifies diverticular bleeding in the sigmoid colon which has stopped spontaneously. He has had three similar episodes over 2 years. The most appropriate definitive management is:
92. A 30-year-old man with familial adenomatous polyposis (APC mutation) undergoes proctocolectomy with ileal pouch–anal anastomosis (IPAA). Six months later, endoscopy reveals multiple polyps in the retained rectal cuff. The correct term for this region and the most important follow-up action are:
93. A 60-year-old man undergoes laparoscopic anterior resection for rectal carcinoma 8 cm from the anal verge. Pre-operative staging MRI shows the tumour involving the mesorectal fascia (CRM <1 mm). The most appropriate neoadjuvant strategy according to current guidelines is:
94. In Lynch syndrome (HNPCC), which mismatch repair (MMR) gene mutation is associated with the HIGHEST cumulative lifetime risk of colorectal cancer?
95. A 55-year-old woman undergoes colonoscopy which reveals a 25 mm flat lesion in the sigmoid colon classified as Paris type IIa + IIc. The lesion is removed by endoscopic mucosal resection (EMR) and histology shows T1 (sm2) colorectal adenocarcinoma with poor differentiation and lymphovascular invasion. What is the recommended management?
96. The Hartmann's procedure involves resection of the rectosigmoid colon with closure of the rectal stump and formation of an end colostomy. In which clinical scenario is reversal of Hartmann's procedure (Hartmann's reversal) associated with the HIGHEST operative mortality and morbidity?
97. Anal squamous cell carcinoma (SCC) is treated with the Nigro protocol. What is the standard chemoradiation regimen in this protocol?
98. The IPAA (ileal pouch-anal anastomosis, J-pouch procedure) is performed for ulcerative colitis. Which postoperative complication is MOST commonly responsible for pouch failure requiring pouch excision in the long term?
99. Transanal total mesorectal excision (TaTME) has been developed as an alternative approach to laparoscopic TME for rectal cancer. What is the PRIMARY anatomical advantage of the transanal approach over laparoscopic TME?
100. The RAPIDO trial compared short-course preoperative radiotherapy (5 × 5 Gy) followed by systemic chemotherapy then surgery versus standard chemoradiotherapy then surgery for locally advanced rectal cancer. The primary endpoint showed superior results in the experimental arm for:
101. Regarding the anatomy of total mesorectal excision (TME), the 'holy plane' of sharp dissection lies between which two fascial layers?
102. A 55-year-old man with a 3 cm rectal carcinoma 6 cm from the anal verge has a staging MRI showing mrT3b (5 mm beyond muscularis propria), mrN1, mrMRF-negative. Per European guidelines (ESMO 2023), the preferred initial treatment is:
103. Lynch syndrome (hereditary non-polyposis colorectal cancer, HNPCC) is caused by germline mutations in mismatch repair (MMR) genes. The revised Bethesda guidelines recommend MMR testing on tumour tissue if the patient is diagnosed with CRC under age 50. Which mutation accounts for the LARGEST proportion of Lynch syndrome cases?
104. In the Delorme procedure for full-thickness rectal prolapse, which of the following correctly describes the technique?
105. A 65-year-old man undergoes resection for rectal cancer. The pathology report shows T3N1M0 with a circumferential resection margin (CRM) of 0.8mm. According to current guidelines, what does this CRM finding indicate?
106. A patient with Lynch syndrome (HNPCC) is diagnosed with colon cancer at age 42. What is the recommended surgical approach compared to sporadic colon cancer?
107. A 55-year-old woman has a 6cm villous adenoma of the rectum at 8cm from the anal verge, with biopsy showing high-grade dysplasia but no invasive cancer. What is the most appropriate surgical approach?
108. The RAPIDO trial compared short-course radiotherapy (SCRT) followed by chemotherapy then surgery versus long-course chemoradiotherapy then surgery for locally advanced rectal cancer. What was the main finding regarding pathological complete response (pCR)?
109. A 50-year-old man has T2N0 anal squamous cell carcinoma (SCC). What is the standard definitive treatment according to the Nigro protocol?
110. A patient with stage IV colorectal cancer has synchronous liver metastases (3 lesions in the right lobe, all resectable). The primary colon cancer is symptomatic (causing obstruction). What is the current surgical strategy?
111. A 45-year-old man is diagnosed with familial adenomatous polyposis (FAP) confirmed by APC gene mutation. He has >1000 colonic polyps and a 2 cm rectal polyp with high-grade dysplasia. What is the recommended prophylactic surgery?
112. The MERCURY study group demonstrated that MRI-predicted resection margin status before rectal cancer surgery correlates with which key outcome?
113. The FOXTROT trial investigated which treatment strategy for locally advanced colon cancer?
114. In transanal total mesorectal excision (TaTME), the primary advantage over conventional laparoscopic TME for rectal cancer is:
115. Defunctioning loop ileostomy is performed after low anterior resection primarily to:
116. The Milligan-Morgan technique for haemorrhoidectomy differs from the Ferguson (closed) haemorrhoidectomy primarily in that:
117. A 60-year-old man with rectal carcinoma at 8 cm from the anal verge undergoes staging MRI pelvis. The tumor is mrT3 N2 M0 with threatened circumferential resection margin (CRM). According to current ESMO/NCCN guidelines, what is the optimal neoadjuvant treatment?
118. Which genetic syndrome is characterized by MUTYH biallelic mutations, multiple colorectal adenomas (typically 10–100), and autosomal recessive inheritance?
119. A 50-year-old woman presents with rectal bleeding. Sigmoidoscopy reveals an anal canal lesion at the dentate line, biopsy confirms squamous cell carcinoma. The standard curative treatment is:
120. A 45-year-old man with familial adenomatous polyposis (FAP) and > 1000 colorectal adenomas undergoes total colectomy. He has a desmoid tumor in the mesentery growing at 3 cm/year. What is the first-line medical management for mesenteric desmoid tumors in FAP?
121. Amsterdam criteria II for hereditary non-polyposis colorectal cancer (Lynch syndrome) requires which of the following sets of conditions?
122. A 65-year-old man with rectal adenocarcinoma has MRI showing T3 tumour with clear mesorectal fascia margin (≥2 mm), N1 disease, at the level of 8 cm from the anal verge. Tumour is mobile on digital rectal examination. The MERCURY trial findings most directly support which management strategy?
123. The plane of surgical dissection in total mesorectal excision (TME) for rectal cancer is the:
124. A 55-year-old man with high-grade dysplasia detected in a 12 mm flat rectal polyp undergoes endoscopic mucosal resection (EMR). Histology shows piecemeal resection with high-grade dysplasia at the lateral margin. The most appropriate next step is:
125. In low anterior resection with a defunctioning loop ileostomy, the ileostomy is most commonly fashioned at which position and level?
126. A 60-year-old male undergoes low anterior resection for a T3N1M0 mid-rectal carcinoma. Post-operatively, histology shows positive circumferential resection margin (CRM+). Which of the following statements about CRM positivity is MOST accurate?
127. The MERCURY trial, which validated MRI staging for rectal cancer, established that MRI can predict which of the following with high accuracy BEFORE surgery?
128. A 55-year-old woman presents with a 3 cm squamous cell carcinoma of the anal canal (above the dentate line). She has no distant metastases. The standard of care first-line treatment is:
129. Lynch syndrome (hereditary non-polyposis colorectal cancer, HNPCC) is confirmed by identifying germline mutations in mismatch repair genes. Which of the Amsterdam II criteria defines the minimum clinical requirement for suspecting Lynch syndrome?
130. A 68-year-old man is discovered to have a synchronous liver metastasis (solitary, 3 cm) from a sigmoid colon adenocarcinoma during staging CT. Both lesions are resectable. The preferred surgical strategy is:
131. A 58-year-old with a rectal cancer at 6 cm from the anal verge undergoes neoadjuvant long-course chemoradiotherapy. Post-treatment assessment shows clinical complete response (cCR). According to the 'watch and wait' strategy, what is the most important concern regarding this approach?
132. The Heald classification of mesorectal planes describes three planes of dissection in rectal surgery. What defines the 'intramesorectal' plane, and why is it surgically undesirable?
133. A 40-year-old with Lynch syndrome (MLH1 mutation) is diagnosed with a right-sided colon cancer. After curative resection, what is the most appropriate surveillance interval for colonoscopy?
134. During an anterior resection for rectal cancer, the surgeon enters the presacral space and encounters profuse venous bleeding from the presacral veins. The most appropriate immediate maneuver is:
135. A patient with locally advanced anal squamous cell carcinoma (T3N0M0) is treated with the Nigro protocol. What are the three components of this regimen?
136. A 62-year-old man is diagnosed with a T3N1M0 rectal carcinoma at 8 cm from the anal verge. Total mesorectal excision (TME) is planned. What is the standard neoadjuvant treatment according to current guidelines?
137. Hinchey classification is used to stage perforated diverticulitis. A patient presents with faecal peritonitis and CT confirms free faecal contamination of the peritoneal cavity with no abscess. What Hinchey stage is this and what is the standard surgical treatment?
138. Lynch syndrome (hereditary non-polyposis colorectal cancer, HNPCC) is diagnosed by Amsterdam II criteria. Which molecular mechanism underlies Lynch syndrome?
139. A 45-year-old man presents with rectal bleeding and a mass at the anal margin. Biopsy shows squamous cell carcinoma. What is the standard first-line treatment for squamous cell carcinoma of the anal canal?
140. A 62-year-old man has a T3N1M0 rectal adenocarcinoma located 7 cm from the anal verge. He receives long-course neoadjuvant chemoradiotherapy and on restaging MRI shows complete clinical response. According to the watch-and-wait approach, which finding mandates surgery rather than surveillance?
141. A 55-year-old patient with Lynch syndrome (MLH1 germline mutation) has had a right hemicolectomy for a Dukes B colon cancer. Surveillance colonoscopy reveals a 1 cm polyp in the sigmoid colon with high-grade dysplasia. What is the recommended management?
142. A 70-year-old man presents with an acutely obstructing sigmoid colon cancer (T3N1M0). He is haemodynamically stable. The current preferred single-stage intervention is:
143. Which of the following best describes the Dukes–Astler–Coller (modified Dukes) classification stage C2 of colorectal carcinoma?
144. A 40-year-old man with FAP who has undergone prophylactic proctocolectomy now develops upper GI symptoms. Endoscopy reveals multiple duodenal polyps with Spigelman stage IV. What is the recommended management?
145. A 62-year-old man undergoes resection for a rectal carcinoma 6 cm from the anal verge. Histology shows T3 N2 M0. According to current guidelines for locally advanced rectal cancer, the preferred sequence of treatment is:
146. The 'watch-and-wait' (non-operative management) strategy after neoadjuvant chemoradiotherapy in rectal cancer is applicable only when which finding is confirmed?
147. A 45-year-old man is found to have synchronous liver metastases from sigmoid colon cancer. He has two bilobar liver metastases (both < 3 cm, no vascular involvement) and a resectable sigmoid primary. His performance status is ECOG 0. The optimal surgical strategy is:
148. In Lynch syndrome (hereditary non-polyposis colorectal cancer), the MMR gene mutation most commonly associated with extracolonic endometrial and ovarian cancers at a higher rate than the others is:
149. A 55-year-old man undergoes colonoscopy for haematochezia. A 3 cm sessile polyp is found in the rectum 5 cm from the anal verge with Paris classification 0-IIa+IIc morphology. Biopsies show high-grade dysplasia. The MOST appropriate next step is:
150. A 40-year-old man has familial adenomatous polyposis (FAP) with >100 colonic polyps. He undergoes restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA). The desmoid tumour risk, which is the leading cause of non-cancer death in FAP, is associated with:
151. Acute ischaemic colitis most commonly affects which segment of the colon and is related to which anatomical watershed zone?
152. A 62-year-old man with rectal cancer at 6 cm from the anal verge is staged cT3N1M0. After long-course chemoradiation, a restaging MRI shows mrTRG 3. The most appropriate surgical approach is:
153. A 58-year-old woman with Lynch syndrome (MLH1 mutation) is diagnosed with right-sided colon cancer (cT3N0M0). After counselling, she opts for colectomy. What extent of resection is recommended in Lynch syndrome patients?
154. The Dukes staging system for colorectal carcinoma was modified by Astler and Coller (MAC). Which MAC stage corresponds to tumour penetrating through the entire bowel wall with NO lymph node involvement?
155. A 45-year-old man is found to have multiple synchronous liver metastases from colorectal cancer — 4 lesions, all in the right lobe, with no extrahepatic disease. After 3 months of FOLFOX chemotherapy, repeat imaging shows 30% size reduction. What is the next best step?
156. The MERCURY trial established that preoperative MRI can accurately define the circumferential resection margin (CRM) in rectal cancer. A threatened CRM on MRI is defined as tumour within:
157. Familial adenomatous polyposis (FAP) caused by APC gene mutations on chromosome 5q21 carries near 100% risk of colorectal cancer. The CLASSIC prophylactic operation recommended when polyp burden is heaviest in the sigmoid and rectum is:
158. The FOXTROT trial examined the role of neoadjuvant FOLFOX chemotherapy in colon cancer. Compared to upfront surgery, neoadjuvant chemotherapy resulted in:
159. A 60-year-old man presents with haematochezia and a mobile, 3 cm rectal tumour 7 cm from the anal verge. MRI shows T2N1 disease with no CRM threat. He undergoes a low anterior resection. Which statement regarding total mesorectal excision (TME) is most accurate?
160. Lynch syndrome (HNPCC) is caused by defects in mismatch repair genes. Among the Amsterdam II criteria, the minimum pedigree requirement includes:
161. In proctology, the Milligan-Morgan haemorrhoidectomy and Parks' submucosal haemorrhoidectomy are open and closed techniques respectively. The Longo procedure (stapled haemorrhoidopexy) acts by:
162. Pseudomyxoma peritonei (PMP) most commonly arises from a perforated mucinous appendiceal neoplasm. The PSOGI consensus classification of PMP distinguishes acellular mucin (grade 0) from which most aggressive histological subtype?
163. In the Dutch TME trial, total mesorectal excision (TME) combined with preoperative short-course radiotherapy (5×5 Gy) compared to TME surgery alone demonstrated the primary benefit of:
164. Lynch syndrome is caused by germline mutations in mismatch repair (MMR) genes. Which gene mutation is associated with the highest lifetime risk of colorectal cancer?
165. A 68-year-old with rectal cancer at 6 cm from the anal verge undergoes anterior resection. During histopathological reporting, the surgeon's concern is the circumferential resection margin (CRM). A positive CRM is defined as tumor within what distance from the surgical margin?
166. Familial adenomatous polyposis (FAP) with severe upper gastrointestinal disease most commonly involves duodenal adenomas, which are staged using the Spigelman classification. At which Spigelman stage is prophylactic surgical intervention typically recommended?
167. In the ASCRS classification of hemorrhoidal disease, Grade IV internal hemorrhoids are best defined as:
168. The SIBDCS (Swiss IBD Cohort Study) data and Cochrane meta-analyses support which timing of surgery in medically refractory ulcerative colitis with toxic megacolon?
169. In the classification of stomas, a loop colostomy differs from an end colostomy primarily in that:
170. The FOxTROT trial demonstrated that neoadjuvant chemotherapy (6 weeks FOLFOX) before surgery for high-risk colon cancer (T3–T4) reduced what primary endpoint compared to adjuvant-only treatment?
171. During total mesorectal excision (TME) for rectal cancer, injury to the hypogastric nerve plexus at the level of the sacral promontory most commonly results in which specific dysfunction?
172. The RAPIDO trial compared short-course radiotherapy (25 Gy/5 fractions) followed by systemic chemotherapy then surgery versus long-course chemoradiotherapy then surgery for locally advanced rectal cancer. The main finding was:
173. Which classification system grades the quality of the mesorectal excision specimen on pathological examination to predict oncological outcomes after rectal cancer surgery?
174. A 29-year-old man with familial adenomatous polyposis (FAP) undergoes a restorative proctocolectomy. He develops a desmoid tumour in the small bowel mesentery 2 years later. Which FAP genotype is most associated with mesenteric desmoid disease?
175. A 55-year-old man with a T1 N0 rectal adenocarcinoma 4 cm from the anal verge, well-differentiated, no lymphovascular invasion on MRI, undergoes transanal local excision. Histology shows clear margins (R0). What is the recommended next step?
176. Total mesorectal excision (TME) in rectal cancer surgery is associated with reduced local recurrence rates. The surgical plane that is dissected in TME is between:
177. A 60-year-old man presents with a T3N1M0 rectal tumour at 5 cm from the anal verge on MRI. The MRI also shows threatened circumferential resection margin (CRM). According to the MERCURY study and ESMO guidelines, the preferred primary management is:
178. Lynch syndrome (HNPCC) is caused by germline mutations in mismatch repair (MMR) genes. Which combination of features constitutes the Revised Bethesda Guidelines for testing a CRC tumour for microsatellite instability (MSI)?
179. A 35-year-old patient with known FAP undergoes surveillance colonoscopy showing thousands of colonic polyps plus a desmoid tumour in the mesentery. The APC mutation has been localised to codon 1328 (between codons 1310–1444, genotype 3B). What surgical option is MOST appropriate for the colonic polyposis given this genotype?
180. Internal haemorrhoids are classified by the Goligher classification. A Grade III haemorrhoid is best described as:
181. A 60-year-old man undergoes anterior resection for rectal carcinoma at 7 cm from the anal verge. The pathology report mentions circumferential resection margin (CRM) involvement. What is the clinical significance of this finding?
182. A 45-year-old man with ulcerative colitis for 20 years is found to have high-grade dysplasia in the sigmoid colon on surveillance colonoscopy. He has no symptoms. What is the MOST appropriate next step?
183. Which of the following BEST distinguishes internal from external haemorrhoids anatomically?
184. A 50-year-old woman presents with a 6 cm carcinoid tumour of the appendix found incidentally during right hemicolectomy for cecal carcinoma. What additional staging workup is specifically required for this tumour size?
185. A 50-year-old woman is diagnosed with a T1 rectal carcinoma 4 cm from the anal verge. It is <3 cm, <30% of rectal circumference, Gl well-differentiated, no vascular/lymphatic invasion on biopsy. What is the MOST appropriate management?
186. The macroscopic circumferential resection margin (CRM) assessed on post-operative MRI (mrCRM) is a critical quality indicator in rectal cancer surgery. What CRM distance predicts significantly increased local recurrence?
187. The Parks classification of anal fistulae defines which type as crossing the external sphincter at some level and passing through the ischiorectal fossa to open on the perianal skin?
188. Watch and wait (non-operative management) after total neoadjuvant therapy for rectal cancer achieving clinical complete response (cCR) is most reliably confirmed by which combination?
189. Anal canal carcinoma (squamous cell carcinoma) is primarily treated with the Nigro protocol (chemoradiotherapy). The standard chemotherapy regimen in this protocol is:
190. A 45-year-old patient with familial adenomatous polyposis (FAP) undergoes proctocolectomy with ileal pouch-anal anastomosis (IPAA). Which additional cancer surveillance is STILL required after surgery?
191. A 70-year-old man presents with a 3 cm anal canal squamous cell carcinoma (SCC) without inguinal lymph node involvement. What is the FIRST-LINE treatment?
192. In familial adenomatous polyposis (FAP), which extraintestinal manifestation is pathognomonic and detectable even before colonic polyps develop, aiding early family screening?
193. The RAPIDO trial compared short-course preoperative radiotherapy (SCRT) followed by systemic chemotherapy versus standard-of-care chemoradiotherapy followed by TME in locally advanced rectal cancer. Its primary endpoint result demonstrated:
194. A 45-year-old man with chronic anal fissure at the posterior midline has failed topical glyceryl trinitrate and diltiazem over 3 months. The next recommended treatment is:
195. A 50-year-old male farmer presents with a painful perianal swelling for 24 hours with fever and purulent discharge at 5 o'clock. Examination confirms a perianal abscess. The most appropriate immediate management is:
196. A 68-year-old man has fourth-degree hemorrhoids not responding to conservative treatment. His preferred definitive treatment that removes the hemorrhoidal tissue permanently is:
197. In the treatment of anal squamous cell carcinoma, the Nigro protocol (chemoradiotherapy with mitomycin C and 5-fluorouracil) is now the standard of care. Which of the following represents the original Nigro protocol dose of radiation?
198. The Dukes staging for colorectal cancer has been largely superseded by TNM, but remains tested. Dukes C2 in the modified Astler-Coller classification refers to:
199. A 28-year-old man is found to have anal cancer (SCC) on biopsy. CT and PET show T2N0M0 staging. What is the standard treatment per Nigro protocol?
200. A 55-year-old patient presents with haematochezia. Colonoscopy shows a 2 cm polyp at 10 cm from the anal verge. Endoscopic mucosal resection (EMR) is performed and histology reveals a T1 rectal adenocarcinoma with submucosal invasion, grade 3 (poor differentiation), and lymphovascular invasion. What is the recommended additional treatment?