Pathology of endometrioid carcinoma

Endometrioid carcinoma is the third most frequent cancer among women in France. They are divided in two groups: type I and type II. This article describes anatomopathological and molecular features of this disease. Type I carcinoma, the most frequent, develops in a context of hyperoestrogenia. Endometrial glandular hyperplasia is the precursor lesion. The histological type is an endometrioid carcinoma. Its prognosis is good. Type II carcinoma is less frequent. It occurs on an atrophic mucosa. It is usually a more aggressive tumor like serous adenocarcinoma, clear cells carcinoma or carcinosarcoma with a poor prognosis. Type I and type II carcinoma also present different molecular pathways. PTEN inactivation, an early event in carcinogenesis, is the most frequent abnormality in type I carcinoma. An average of 28% of type I carcinoma also acquire PI3K mutations. On the contrary, P53 mutation is involved in 90% of type II carcinoma. Identifying and understanding these two types of endometrial carcinoma led to various therapeutic management.