In this case, small cell carcinoma of the endometrium extends through the entire myometrial wall to the serosal surface.
At higher power, one can appreciate the neuroendocrine features. The cells are hyperchromatic with scant cytoplasm.
Broad bands of neoplastic small cells invade and dissect into the myometrium.
Extensive lymphovascular invasion was present.
Small cell carcinoma of the endometrium (SCCE) is extremely rare, and to date, approximately 60 cases have been reported in the English medical literature.
The proposed criteria for diagnosing this tumor are as follows: (1) unequivocal evidence of endometrial origin; (2) a dense sheet-like growth of morphologically similar small to intermediate-sized tumor cells examined by standard H&E stained sections; (3) immunohistochemical reactivity for one or more neuroendocrine markers.1,2
Grossly, these tumors are exophytic mass. Microscopically, a dense infiltrate of small blue round cells involve the endometrium and often, invade into the myometrium. IHC studies demonstrate positivity for NSE, synaptophysin and variable positivity for chromogranin.
Small cell carcinoma of the female genitourinary tract is a rare aggressive tumor and most often arises in the cervix. There are only 60 reported cases arising from the endometrium. In a review of 60 cases, the average age of presentation is 60 (about 10 years older than endometrial adenocarcinoma) and the women tend to be parous (average of 2 children).1
SCCE also presents at advanced stages -- thus, SCCE appear to be more similar to type II endometrial carcinoma (ie. serous or clear cell type) rather than type II endometrial carcinoma (endometrioid, mucinous type).2
1 Bige O, Saatli B, Secil M et al. Small cell neuroendocrine carcinoma of the endometrium and laparoscopic staging: a clinicopathologic study of a case and brief review of the literature. Int J Gynecol Cancer 2008:18;838-861.
2 Katahira A, Akahira J, Niikura H et al. Small cell carcinoma of the endometrium: report of three cases and literature review. Int J Gynecol Cancer 2004;14;1018-23.
Van Hoeven KH, Hudock JA, Woodruff JM, Suhrland MJ. Small cell neuroendocrine carcinoma of the endometrium. Int J Gynecol Pathol 1995;14:21–9.