Gyne Pathology Practice Question

Which of the following immunohistochemical panels would be most useful for distinguishing endometrioid adenocarcinoma versus endocervical adenocarcinoma?

Show Answer and Explanations

vimentin, ER, PR, CEA, p16, p53 — Correct answer

Correct. Endometrioid adenocarcinoma is more likely to be positive for vimentin, ER and PR. Endocervical adenocarcinoma is more likely positive for CEA, p16 and p53, but can show some positivity for ER and PR, (although the majority stain for one or the other, less than 5%, will stain with both).

vimentin, ER, PR

Incorrect. These stains are more likely positive in endometrioid adenocarcinoma, but other stains should be added for confirmation.

CEA, p16, p53

Incorrect. These stains are more likely positive in endocervical adenocarcinoma, but other stains should be added for confirmation.

p53, PTEN

Incorrect. Most endometrioid adenocarcinomas stain positive for PTEN, and cervical adenocarcinomas stain positive for p53, but these two markers are not enough to make the distinction. The combination of p53 and PTEN is of prognostic value for endometrial carcinoma. Most serous adenocarcinomas, and high grade endometrioid adenocarcinomas are positive for p53 - p53 staining is correlated with worse prognosis. PTEN is the opposite. Loss of PTEN staining (the presence of PTEN mutation) is associated with microsatellite instability. PTEN is also more likely positive in serous carcinoma.

PTEN, p53, IMP3

Incorrect. PTEN, p53 and IMP3 are more likely positive in uterine serous papillary carcinoma compared to endometrioid adenocarcinoma.

p16, ER, WT-1, IMP3, p53

Incorrect. This panel is more likely positive in ovarian papillary serous carcinoma, particularly the combination of positivity for both WT-1 and ER, compared to uterine papillary serous carcinoma.

Summary

Summary: Endometrioid adenocarcinoma: vimentin, ER and PR; endocervical carcinoma: p16, p53, CEA.