Review of immunohistochemical typing of endometrial carcinoma at the Lagos University Teaching Hospital

Background: Categorization of endometrial carcinomas as type I and II provides useful insights into their different risk factors, pathogenesis and biologic behaviours.
Aim: To determine the immunohistochemical classifications of endometrial carcinomas in Nigerian women.
Design: A retrospective review of histopathologic slides of cases of endometrial carcinomas seen at the Lagos University Teaching Hospital (LUTH) over a 5-year period. The slides were reviewed, and the diagnoses made according to the WHO nomenclature. The classification of endometrial carcinomas into Type I and II was made by immunohistochemistry using antibodies to ER, PR, p53 and Ki-67.
Results: Eight cases of endometrial adenocarcinoma were reported accounting for 53.3% of all endometrial malignancies. Of these, only 1 case showed the classic type I immunophenotype while type II staining pattern was seen in 4 cases. The remaining 3 cases had equivocal immunophenotypes: one was p53+ but showed ER+, PR+ and high Ki-67 index; the second was p53-, ER+, PR+ but had a high Ki-67 expression; while the last was p53-, but ER-, PR- and had high Ki-67 expression.
Conclusion: Endometrial carcinomas in Nigerian women are more likely to be type II carcinomas. A reasonable proportion of the cases were equivocal thus requiring further categorization with molecular studies.