We report a case of metastatic
bladder tumor from
gastric cancer, which was difficult to differentiate from urachal
tumor preoperatively, especially computed tomographic scan, cystoscopy, and biopsy. A 51-year old man visited our hospital with the chief complaint of asymptomatic gross
hematuria. He had received subtotal
gastrectomy for
gastric cancer two years earlier. Because the possibility of urachal
tumor could not be excluded, en bloc segmental resection of the bladder, the urachus, and the umbilicus was carried out. This case was diagnosed as
adenocarcinoma histologically, but it was difficult to determine whether the case was a metastatic
bladder tumor from
gastric cancer or urachal
tumor by the routine staining method.
High iron diamine-alcian blue and paradoxical
concanavalin A (ConA) stainings were performed, on the surgical specimens of this case and other urachal
tumor already diagnosed. In these cases, metastatic
bladder tumor could be differentiated from an urachal one by mucohistochemically paradoxical Con A staining. Seventeen cases of metastatic
bladder tumor from
gastric cancer including our cases were collected from the Japanese literature and reviewed.