腎細胞癌との鑑別が困難であった後腎腺腫の1例

Metanephric adenoma：A case report

　61歳，女性。腹部CTにて，右腎臓に直径40mm大の腫瘤を認めた。造影CTでは，全体としてhypovascularであり，内部構造は，囊胞状の所見であった。腎細胞癌の診断のもとに，経腹的根治的腎摘出術を施行した。病理組織学的診断は，後腎性腺腫であった。後腎性腺腫は，稀であり，われわれが調べた限りでは，本症例は本邦22例目にあたる。

　A 61-year-old female presented with a right renal mass detected by CT scan at a mass health screening. MRI revealed a solid tuomr in the lower pole of the right kidney measuring 40mm in diameter. Radical nephrectomy was performed under the diagnosis of suspected renal cell carcinoma. Histlogically,the tumor was composed of epithelial,small and uniform cells with scant cytoplasm and hyperchromatic round nuclei,which formed a tubular or glomerular-like structure. The histological diagnosis was metanephric adenoma.