成人型Wilms' tumorの1例

Abstract

症例は22歳女で, 肉眼的血尿と右背部痛を主訴とした.画像所見から右腎の悪性腫瘍を強く疑い, 経腹式根治的右腎摘出術を施行した.腫瘍は腎下極にあり, 径5×5×5cmの黄白色・充実性で, 明らかな腎被膜外への進展はみられなかった.顕微鏡学的には, 好塩基性の胞体を有する核細胞質比の大きい上皮性腫瘍細胞の管状及び管状乳頭状の増生がみられ, 一部に芽腫成分を認めた.間葉系成分は少ないものの, ごく一部に分化した軟骨組織を認めた.これらの所見から成人型Wilms' tumorの上皮型と診断した.術後補助療法は患者の強い希望で施行せず経過観察となったが, 術後26ヵ月経過して再発は認めない.本例を加えた成人型Wilms' tumorの報告例16例について臨床的検討を行ったところ, 疼痛や腹部腫瘤, 血尿など何らかの臨床症状を呈した症例が多かった.また, 初診時に隣接臓器への浸潤もしくは血行性遠隔転移を認めた症例が半数近くを占めていた

We present a case report of adult Wilms' tumor and reviewed from 1981. A 22-year-old woman with chief complaints of gross hematuria and right backache was introduced to our hospital in March 1998. Abdominal computed tomography (CT) revealed a solitary irregular mass (5.0 cm) at the lower pole of right kidney with no contrast medium enhancement. Angiography showed a hypovascular character, but irregular vascularization was found in the tumor. We performed a radical nephrectomy with a preoperative diagnosis of malignant renal tumor. Finally, adult Wilms' tumor (epithelial type) was diagnosed by pathological examination. We retrospectively studied the clinical and radiological features in 16 reported cases of adult Wilms' tumor from 1981. The average age was distinctly younger than that of renal cell carcinoma. Nearly half of the cases were at an advanced clinical stage (direct invasion or metastasis to other organs) at first consultation. Radiologically, Wilms' tumor tends to be visualized as a low density mass in the precontrast CT scan (75.0%) and hypovascular tumor by selective angiography (84.6%). Although this is not a definitive character to distinguish adult Wilms' tumor from renal cell carcinoma, it may be useful information for differential diagnosis.