Minimal deviation adenocarcinoma of endometrioid type may arise in the isthmus: clinicopathological and immunohistochemical study of two cases.

Clinicopathological and immunohistochemical features of minimal deviation adenocarcinoma (MDA) of endometrioid type which may have arisen in the isthmus are presented. Hysterectomy specimens from two women, one 39 years of age and the other 64 years of age, showed the presence of endometrioid-type adenocarcinoma with minimal atypia and without back-to-back arrangement of the glands, which was consistent with a histological diagnosis of endometrioid MDA. However, the tumorous glands were most abundant in the isthmus, and extensively infiltrated into the cervical stroma, vagina, parametrium, and corpus in one case, and the tumor was confined to the isthmus in the other. Immunohistochemically, the tumorous glands were CEA-positive and vimentin-negative in both cases. p53 protein expression was found in one case. Histogenetic origin of MDA of endometrioid type is discussed.