[Early urachal carcinoma diagnosed by magnetic resonance imaging: a case report].

A case of an early urachal carcinoma is reported. A 46-year-old man was referred to our hospital because of urinary bladder tumor. Microhematuria had been detected by a medical health examination two months earlier. Gold punch biopsy under cystoscopy proved adenocarcinoma. Sagittal view in magnetic resonance imaging (MRI) clearly demonstrated a small tumor at the bladder dome. En bloc partial cystectomy and pelvic lymphadenectomy was performed under diagnosis of early urachal carcinoma. Microscopically, papillary adenocarcinoma like colon carcinoma was revealed, but the bladder wall and urachus were free from the infiltration of carcinoma cells and no pelvic lymph node metastasis was found. There has been no evidence of recurrence or metastasis 5 months after the operation.