Primary retroperitoneal mucinous cystadenocarcinoma during pregnancy.

Primary retroperitoneal mucinous cystadenocarcinoma (PRMC) is an extremely rare tumour. This case report describes the treatment and prognosis of a patient with PRMC during pregnancy. This is the third case of PRMC in a pregnant woman, worldwide. The patient was a 37-year-old woman presenting with a left mid-abdominal and pelvic semisolid, cystic mass at 29 weeks' gestation. At 30 weeks' gestation, she underwent an exploratory laparotomy, which revealed a solid tumour (22 × 13 × 11 cm) with an intact capsule extending from the inferior pole of the left kidney to the pelvic inlet in the left retroperitoneal area. The tumour had adhesions with the surrounding connective tissue and could be excised with its capsule intact. In conclusion, based on the limited information available, a PRMC with no visible dissemination excised with an intact capsule appears to have a good prognosis. Tumour excision may be adequate for treatment of PRMCs in the extragenital space and with no dissemination.