Peritoneal mucinous cystadenocarcinoma of probable urachal origin: a challenging diagnosis.

This report describes the case of a mucinous cystadenocarcinoma of probable urachal origin that presented with mass effect, precipitating deep venous thrombosis and pulmonary embolism. The patient presented with acute symptoms of leg swelling, pain and dyspnoea, and a vague awareness of lower abdominal distension. Computer tomography showed a cystic mass closely related to the anterior abdominal wall and the superior aspect of the bladder. A 1500 cm(3) cyst adherent to the dome of the urinary bladder was resected on laparotomy. Partial cystectomy was not carried out in the belief that the cyst represented a benign lesion. Subsequent imaging has shown cystic changes in the anterior bladder wall, and the patient has been referred for partial cystectomy.