尿膜管癌からの転移性脳腫瘍の1例

Metastatic Brain Tumor Originating from Urachal Carcinoma ： Case Report

Ⅰ．はじめに

　尿膜管癌は尿膜管より発生する癌腫であり，全膀胱腫瘍の0.17～0.34％という極めて稀な腫瘍である⁷⁾．局所浸潤傾向が強く予後不良で，5年生存率は35％前後とされている⁹⁾．遠隔転移は晩期になるまでみられず，肺，肝，骨などへの転移が報告されている⁷⁾．

　しかし，尿膜管癌の脳転移については過去5例の報告をみるに過ぎない^1,3,5,6,8)．

　今回われわれは，脳転移巣発見後に原発巣の尿膜管癌が診断された症例を経験し，その診断治療等について，若干の文献的考察を加え報告する．

The authors presented a patient with metastatic brain tumor originating from urachal carcinoma. A 64-year-old female was admitted to our hospital with complaints of memory disturbance,indifference and apathy of 3 months duration. Head CT and MRI on admission showed a round mass with perifocal edema in the right frontal lobe. After administration of Gd-DTPA,the mass lesion showed ringed enhancement effect. Pelvic MRI scan revealed a bladder tumor,which was diagnosed as urachal carcinoma. The brain lesion was suspected to have metasta sized metastatic from urachal carcinoma,and was excised by craniotomy. Histology of the brain tumor was identical to that of urachal carcinoma. Postoperatively the patient received local radiation therapy,but died of multiple metastasis to lung and local recurrence,18 months later. Urachal carcinoma is an extremely rare tumor,comprising 0.17-0.34％ of all bladder tumors. Though this rare tumor carries a poor prognosis,it may be effective for longer survival of a patient to treat the metastatic brain lesion with surgery and radiation.