Florid cystic endosalpingiosis associated with a retroperitoneal leiomyoma mimicking malignancy: a case report

Abstract

Florid cystic endosalpingiosis (FCE) is a rare type of endosalpingiosis that presents as a mass-like lesion. Here we report an unusual case of FCE associated with a retroperitoneal leiomyoma. A 46-year old female presented with a palpable abdominal mass. A pelvic CT revealed a 23.5×16.3×9.4 cm sized multilocular cystic and solid mass in the retroperitoneum. Surgical excision of the mass was performed. Microscopically, the cystic spaces were lined by a single layer of ciliated tubal epithelium. The solid areas consisted of thick bundles of spindle cells. There were no cytologic atypia, mitosis or necrosis. The spindle cells were positive for actin and desmin, and were negative for c-kit, CD34, S100 and HMB-45, confirming the diagnosis of FCE associated with retroperitoneal leiomyoma.

Keywords: Florid cystic endosalpingiosis; endosalpingiosis; leiomyoma; mimicker; retroperitoneal mass.

Figure 1

Radiologic and gross findings. A. Pelvic CT reveals a 23.5×16.3×9.4 cm sized retroperitoneal mass at the right anterior pararenal space. It has a lobulated contour with multiloculated cystic (C). and solid (S) portions. B. Gross examination reveals a gray to white colored, lobulated solid and cystic mass, measured 23.5×16.3×9.4 cm. On cut section, multilocular cysts filled with clear serous fluid were mainly located at the peripheral area, and white colored multinodular solid areas with whirling features were present at the central portion.

Figure 2

Microscopic findings. A. Solid mass lesion at the lower field with cystic area at the upper field. B. The cysts were lined with a single layer of ciliated tubal epithelium. There are no endometrial stromal-like areas near the epithelial lining. C. The solid area consisted of thick bundles of spindle cells with elongated cigar shaped nuclei. D. On immunohistochemistry, the epithelial lining were positive for cytokeratin 7. E. The spindle cells were positive for actin. F. The spindle cells were negative for HMB-45.