A 35-year-old woman has an abnormal Pap smear showing atypical glandular cells. Cone biopsy reveals neoplastic glandular cells replacing endocervical glands with preservation of the normal glandular architecture ('gland within gland' or 'cribriform' pattern). Stromal invasion is absent. p16 shows block positivity. What is the diagnosis?
- A Microinvasive squamous cell carcinoma
- B Cervical intraepithelial neoplasia grade 3 (CIN 3)
- C Cervical adenocarcinoma in situ (AIS) ✓
- D Endometriosis of the cervix
Correct answer: C. Cervical adenocarcinoma in situ (AIS)
Explanation
Cervical adenocarcinoma in situ (AIS) shows neoplastic glandular epithelium replacing normal endocervical glands with preserved overall architecture, apical mitoses, and apoptotic bodies. It is HPV-driven (HPV-18 more common than HPV-16) and shows p16 block positivity. CIN 3 is squamous dysplasia. Microinvasive carcinoma shows stromal invasion. Endometriosis has endometrial stroma and is p16 negative.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.