Low-grade endometrial stromal sarcoma with extensive sex cord differentiation, heterologous elements, and complex atypical hyperplasia: Case report and review of literature

Abstract

•Endometrial stromal sarcoma (ESS) may have sex cord differentiation, usually focal.•Diagnosis of ESS is difficult when variant morphology predominates.•Prognosis differs between ESS and UTROSCT; therefore, distinction is critical.•Extensive tumor sampling is mandatory to identify neoplastic endometrial stroma.•Sex cord differentiation may be associated with endometrial hyperplasia.

Keywords: Endometrial stromal sarcoma; Endometrial stromal tumor; Uterine tumor resembling ovarian sex cord tumor.

Fig. 1

A–B – Gross and microscopic sections through tumor demonstrate permeative growth into surrounding myometrium. C – Tumor (right) adjacent to uninvolved endometrium (left). Note the resemblance between benign and malignant endometrial stroma. D – Tumor cells whorl around a delicate capillary network. E – Sheets and nodules of Leydig-like cells occupied the majority of the tumor. F – Sertoli-like elements were also present. G – Heterologous glands resemble colonic epithelium with columnar absorptive cells and goblet cells. Leydig-like cells are also seen (center). H – Complex atypical hyperplasia is present in the overlying endometrium. Note the differing cytology of neoplastic glands compared with a single entrapped benign gland. (b–h. hematoxylin and eosin; b–c. 40 ×, d. 100 ×, e. 20 ×, f–h. 100 ×).

Fig. 2

Leydig-like cells are positive for calretinin (A) and negative for CD68 (B). Surrounding neoplastic endometrial stromal cells are positive for CD10 (C). (a–c. 400 ×).

Fig. 3

Endometrial glands are positive for CK7 (A) and negative for CK20 (B). CDX2 is negative in the majority of endometrial glands (C) with only weak staining in rare glands, while ER is strongly and diffusely positive (D). Conversely, colonic-type epithelium is negative for CK7 (E) in the majority of glands and positive for CK20 (F). CDX2 is strongly and diffusely positive (G) in the colonic-type glands, while ER is uniformly negative (H). (a–h. 200 ×).