Symplastic Atypia in Neoplastic and Non-neoplastic Endometrial Stroma: Report of 3 Cases With a Review of Atypical Symplastic Cells Within the Female Genital Tract

Abstract

We report 3 cases in which endometrial stromal cells exhibited marked nuclear atypia with a symplastic appearance. Two cases involved non-neoplastic endometrial stroma, one within an ovarian endometriotic cyst and the other within normal eutopic endometrium. In the third case, the symplastic change involved the neoplastic cells of an endometrial stromal sarcoma. Symplastic endometrial stromal cells have rarely been described in normal endometrium and in endometrial stromal sarcoma but, as far as we are aware, this phenomenon has not been reported previously in endometriosis. In the 3 cases, the atypical cells were a focal finding. The abnormal nuclei were markedly enlarged, atypical, and hyperchromatic with multilobated forms but without mitotic activity. This unusual phenomenon is a benign change when involving non-neoplastic endometrial stroma and is of no clinical significance. It is analogous to the presence of atypical symplastic nuclei in normal tissues and in other pathologic lesions in the female genital tract. In reporting these cases, we review normal tissues and pathologic lesions in the female genital tract with atypical symplastic nuclei.