Coexistence of endometrial mesonephric-like adenocarcinoma and endometrioid carcinoma suggests a Müllerian duct lineage: a case report

Abstract

Background: Endometrial mesonephric-like adenocarcinomas exhibit classical histologic features of mesonephric carcinoma; however, it remains unclear whether these tumors represent mesonephric (Wolffian) carcinoma or endometrioid (Müllerian) carcinomas that closely mimic mesonephric carcinoma.

Case presentation: A 32-year-old Japanese primigravida presented with atypical vaginal bleeding. An endometrial biopsy suggested low-grade endometrioid carcinoma, and she was administered medroxyprogesterone acetate. Her tumor recurred 6 years later, and she underwent hysterectomy, salpingo-oophorectomy, and omentectomy, at which point she was diagnosed with mesonephric-like adenocarcinoma of the uterine endometrium. Retrospective pathological review of the initial biopsy confirmed coexisting low-grade endometrioid carcinoma and mesonephric-like adenocarcinoma of the uterine endometrium. On immunohistochemistry, the endometrioid carcinoma component was diffuse positive for estrogen and progesterone receptors but negative for thyroid transcription factor 1. However, the mesonephric-like adenocarcinoma component exhibited a mixture of estrogen receptor- and thyroid transcription factor 1-positive cells within the same glands.

Conclusions: We encountered a patient with coexisting endometrial mesonephric-like adenocarcinoma and low-grade endometrioid carcinoma, which was treated using medroxyprogesterone acetate therapy, resulting in recurrence of mesonephric-like adenocarcinoma alone. These clinicopathological findings support the prevailing notions that mesonephric-like adenocarcinoma is a Müllerian adenocarcinoma exhibiting mesonephric differentiation.

Keywords: Endometrial cancer; Endometrioid carcinoma; Medroxyprogesterone acetate therapy; Mesonephric-like adenocarcinoma; Müllerian duct.

Fig. 1

Magnetic resonance imaging and macroscopic analysis: (a) T2-weighted image of the initially diagnosed tumor (red arrow). (b) T2-weighted image of the recurred tumor (red arrow). (c) The endometrial mass (red arrows) was 40 × 23 mm-sized in the left wall of the uterine body and (d) had yellow-whitish cut surface

Fig. 2

Histology and immunohistochemistry of the recurred tumor. The tumor had a variety of histologic patterns including (a, 20×) tubular and glandular, (b, 20×) papillary, and (c, 40×) spindled and solid with a heterologous element (cartilage without atypia). Immunohistochemical analysis showed positive staining for (d, 2 × 0) thyroid transcription factor 1 and (e, 20×) GATA-3; however, the tumor was negative for (f, 20×) estrogen receptor

Fig. 3

Histology and immunohistochemistry of the initially diagnosed tumor. The tumor had (a, 20×) a low-grade endometrioid carcinoma component and (d, 20×) a mesonephric-like adenocarcinoma component. Immunohistochemically, the endometrioid carcinoma was diffuse positive for (b, 20×) estrogen receptor (ER) and negative for (c, 20×) thyroid transcription factor 1 (TTF-1). The mesonephric-like adenocarcinoma showed a transition pattern with a mixture of cells positive for (e, 20×) ER- (a Müllerian duct marker) and (f, 20×) TTF-1- (a Wolffian duct marker) within the same glands (asterisk)