Huge polypoid endometriosis: report of a case and review of the literature

Abstract

'Polypoid endometriosis' is a rare variant of endometriosis. We describe a case of an extremely large polypoid endometriosis mimicking a malignant tumor. A 37-year-old nulliparous woman was referred due to the rapid growth of an endometriotic cyst of the ovary and a high serum CA125 level. MRI revealed solid components in the pelvic mass. These preoperative clinical data were compatible with an ovarian carcinoma. A frozen section of the tumor biopsy showed as if an adenosarcoma, but finally the diagnosis of polypoid endometriosis with decidual change was made on permanent section. Polypoid endometriosis is a part of the differential diagnosis for malignant tumors in women with endometriosis, and we should consider carefully decision making for treatment.

Keywords: Adenosarcoma; Decidual change; Polypoid endometriosis; Uterine serosa.

Fig. 1

Pelvic MRI: T2-weighted imaging shows irregular shaped mass with solid components occupying the whole pelvis

Fig. 2

Macroscopic findings: a cauliflower-like polypoid mass arising from the serosa of the uterus. b Both ovaries are present separately from the tumor

Fig. 3

Microscopic findings: the polypoid lesion consisted of endometriosis with decidual change. a The tumor is covered with monolayered columnar epithelia on the surface. A dense cellular layer and relatively loose cellular layer were located under the epithelial layer. b Stromal cells are polygonal having abundant cytoplasm and an enlarged nucleus with prominent nucleoli

Fig. 4

Immunochemical findings: a estrogen receptor is positive on most epithelial and stromal cells, b a few stromal cells are positive for CD10, c most stromal cells are strongly positive for vimentin, d MIB-1 index is 5 %

Fig. 5

Some parts of the tumor are composed of endometrium-like tissue showing the secretory phase