A 60-year-old woman is diagnosed with endometrial carcinoma. Histopathology shows a high-grade tumor with papillary architecture, prominent nucleoli, and psammoma bodies. Immunohistochemistry shows p53 aberrant (mutant) pattern and p16 diffuse positivity. What is the most likely diagnosis?
- A Uterine serous carcinoma ✓
- B Endometrioid adenocarcinoma grade 3
- C Clear cell carcinoma
- D Carcinosarcoma (MMMT)
Correct answer: A. Uterine serous carcinoma
Explanation
Uterine serous carcinoma is characterized by papillary architecture, high-grade nuclei, prominent nucleoli, and psammoma bodies. The p53 mutant pattern (diffuse strong or null) is a hallmark, present in over 90% of cases. It accounts for 10% of endometrial cancers but causes disproportionate mortality. Endometrioid grade 3 typically has PTEN/PAX2 loss and wild-type p53. Clear cell carcinoma shows nuclear hobnailing and hyaline bodies. Carcinosarcoma has both malignant epithelial and sarcomatous components.
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.