Signet-ring cell carcinoma of urachus: a case report and review of literature.

Signet-ring cell carcinoma of the urachus and bladder is a rare lesion. Its histological picture is unique and similar to linitis plastica of stomach. The tumor arises through metaplasia of the totipotent transitional epithelium lining the urachus. It is a highly malignant tumor with propensity for local invasion and distant metastasis, and carries a uniformly poor prognosis. Herein we report one such rare case of urachal carcinoma who is free of disease for 2 years after surgical treatment.