A Huge Asymptomatic Urachal Mucinous Cystic Carcinoma: A Case Report With Differential Diagnosis and Surgical Considerations.

Cystic mucinous neoplasms of urachal origin cover a wide spectrum of benign and malignant lesions arising from the remnants of the urachus. They display various degrees of tumor cell atypia and local invasion, with no reported cases of metastasis or recurrence after complete surgical resection. We present a 47-year-old man who referred to our Surgical Department due to an abdominal cystic mass incidentally found upon abdominal ultrasound. He underwent en block resection of the cystic mass along with partial bladder dome cystectomy. The histopathology of the resected specimen revealed a cystic mucinous epithelial tumor of low malignant potential with areas of intraepithelial carcinoma. The patient showed no evidence of disease recurrence or distant metastasis 6 months after resection and is scheduled for follow-up with serial MRI or CT scans and blood tumor markers over the next 5 years.