Primary retroperitoneal mullerian adenocarcinoma

Abstract

Mullerian tumors are extremely rare malignancies in the retroperitoneum. We report a case of a 46-year old woman who presented with an eight year history of lower abdominal mass. Ultrasonography (US) and computed tomography (CT) demonstrated a 15×10 cm cystic mass in the left lower retroperitoneum. As serial percutaneous needle aspiration cytology was negative for malignancy, she was observed for seven years. Eleven months ago, the mass was excised. The histopathology was reported as mucinous adenocarcinoma of the retroperitoneum. Six cycles of intraperitoneal (IP) chemotherapy was administered during the last six months after diagnosis of recurrence by aspiration cytology and high serum tumor markers (CEA, CA19-9). A few days ago, positron emission tomographic (PET) scanning showed evidence of local recurrence and single vertebral metastasis, so she was admitted again for systemic chemotherapy. Meticulous revision of additional sections of the tumor revealed papillary, serous, mucinous, and endometrioid subtypes of the mullerian adenocarcinoma. To our knowledge, there has been no similar case described in the literature.

Keywords: adenocarcinoma; mullerian tumor; retroperitoneum.

Figure 1

(A) Contrast-enhanced abdomino-pelvic CT scan shows a large unilocular cystic mass in the left retroperitoneal space. There is an enhancing solid portion in the posterolateral side of the cyst. (B, C) Photograph of cut specimens of the cyst shows cobble stone appearance with mural nodules. The resected part of left fallopian tube is shown (arrows).

Figure 2

(A) CT scan failed to show relevant data. (B) A 18-FDG PET scintigraphy. There is intense focal area of 18-FDG activity in the left iliac fossa which corresponds to the same slice of CT scan. This is consistent with recurrent disease (peritoneal surface implant). The right paracolic gutter adjacent to the cecum in the right iliac fossa has hypermetabolic activity. (C) Increased tracer activity is in the vertebral body of the last thoracic vertebra, which may represent metastatic deposit.

Figure 3

Histological findings of the retroperitoneal tumor, (A, B) showing branching papillae and apparently detached epithelial cell clusters. Atypical epithelial cells with pleomorphic nuclei and frequent mitotic figures can be seen. (H&E, ×40, ×100). (C, D) showing the columnar cells of mucinous adenocarcinoma portion with many goblet cells and pseudostratification. (H&E, ×40, ×100). (E, F) showing the characteristic tubular glands of the endometrioid subtype. The cells have tendency for stratification, and having oval nuclei (H&E, ×40, ×100). (G) A positive result for CK7 staining in the adenocarcinoma cells (×100). (F) stromal cells show immunoreactivity to CD10 (×100).