Renal oncocytoma treated by surgical enucleation: a case report

Abstract

46歳女.健診時の超音波検査で右腎腫瘤を指摘され受診.CT, 血管撮影で, 腫瘤は, 腎オンコサイトーマが疑われた.迅速病理の結果は, オンコサイトーマの可能性大で悪性像はみられないとの診断であった為, 予定通り核出術で手術は終了した.摘出標本の病理組織は, 好酸性顆粒状の細胞質を持ち, 核は類円形で核異型は乏しく核分裂像もみられなかった.電顕像では, 多数のミトコンドリアが認められた

We experienced a case of renal oncocytoma, in a 46-year-old woman. At a health examination, ultrasonography revealed a right renal tumor, and she was admitted to our hospital for evaluation. From the ultrasonogram, computerized tomography (CT) and angiography, we suspected a renal oncocytoma, but renal cell carcinoma was not completely ruled out. Since the location of the tumor seemed suitable for a local resection, we scheduled a surgical enucleation, but we intended to switch to a radical nephrectomy if examination of a frozen-section suggested renal cancer. Because the frozen findings were suggestive of an oncocytoma without malignancy, the surgical enucleation procedure was completed as scheduled. Pathological findings of the resected specimens were characterized by granular eosinophilic cytoplasm, and rounded nuclei without nuclear pleomorphism or mitotic figures. Electron microscopic studies revealed an increased number of mitochondria. The patient was accordingly diagnosed as having renal oncocytoma. We also reviewed the literature to elaborate procedures for a preoperative diagnosis and therapy for renal oncocytoma.