Heterologous carcinosarcoma of Douglas' pouch with adenocarcinomas of the fallopian tube and the peritoneal cavity

Primary peritoneal carcinosarcoma arising from the Douglas pouch: A case report

Primary peritoneal carcinosarcoma is extremely rare and only few cases have been reported in the literature to date. We herein present a case of carcinosarcoma of the Douglas pouch in a 73-year-old Japanese woman. The patient complained of fever and lower abdominal pain, and a large pelvic mass (>10 cm in diameter) was detected, with rectal invasion. Laparotomy was performed and revealed a left ovarian abscess and a Douglas pouch mass; however, there was no obvious tumor involvement of the bilateral ovaries or uterus. The patient underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy and tumor debulking, with a reduction rate of ~30%. Sigmoid colostomy was also performed due to the deep and wide rectal invasion. Histologically, the tumor was composed of a mixture of ovarian high-grade serous carcinoma and spindle-cell sarcoma mimicking leiomyosarcoma. Immunohistochemically, the serous carcinoma component was positive for cytokeratin (CK)7, Wilms' tumor-1 and p53 (null type), while CDX-2 and CK20 were negative. The spindle-cell sarcoma component was positive for vimentin and α-smooth muscle actin. The present case was diagnosed as carcinosarcoma of the homologous type derived from the peritoneum in the Douglas pouch. The patient received several courses of combination chemotherapy with paclitaxel, carboplatin and bevacizumab, and achieved complete remission. The principal treatment for such cases is surgery, and several chemotherapeutic regimens, including paclitaxel and carboplatin, or cisplatin and ifosfamide, have been reported. The accumulation of more clinical cases is crucial for understanding the clinicopathological characteristics of these rare tumors and establishing effective therapeutic strategies.

Carcinosarcoma in the pouch of douglas

INTRODUCTION

Only one case of carcinosarcoma in the pouch of douglas has been reported in the English literature.

CASE

The author herein reports a case of carcinosarcoma of the pouch of douglas. A rapidly growing tumor (10 cm in diameter) was found in the pelvic cavity of a 51-year-old woman, and an operation was performed for the clinical diagnosis of left ovarian malignancy. However, it was found that the tumor was located in the pouch of douglas, free of ovarian involvement. Because the tumor was impossible to resect totally, an incisional biopsy was performed. Histologically, the tumor showed a mixture of squamous cell carcinoma, atypical epithelial cells occasionally forming tubules, myxomatous spindle cell sarcoma, and chondrosarcoma. The tumor showed abundant vessels, hemorrhage and necrosis. Immunohistochemically, the squamous cell carcinoma and atypical epithelium components were positive for cytokeratins, CEA, CA125, and p53 protein. The spindle cell sarcoma and chondrosarcoma components were positive for vimentin and p53 protein. The overall Ki-67 labeling was 30%. The author diagnosed the present case as carcinosarcoma of heterologous type.

CONCLUSION

The present case shows that carcinosarcoma can occur in the pouch of douglas. It may arise from misplaced Mullerian duct remnants in the pouch of douglas.