腎細胞癌と鑑別が困難であった腫瘤形成性慢性腎盂腎炎の1例

Abstract

症例は62歳男で, 臨床所見と画像所見から右腎細胞癌を強く疑い腎摘出術を施行したが, 病理組織検査の結果は慢性腎盂腎炎であった.術前に炎症性腫瘤と診断し得なかった要因として, 発熱や尿路感染等の症状がなく, CRPも陰性を示し, 造影CT・造影MRIで腫瘤性病変が増強効果を示したこと等が挙げられた

We experienced a rare case of tumor-forming type of chronic pyelonephritis that could hardly be differentiated from renal cell carcinoma. A 62-year-old man was admitted to our department with right renal tumor which was discovered when he underwent examination for gastric cancer. Abdominal ultrasound sonography and computed tomography revealed a mass in the middle portion of the right kidney, measuring 3.8 x 3.5 cm in diameter, with irregular surface and isoechoic and isodense inner mass. Renal angiography demonstrated a hypervascular area in the middle portion. Radical nephrectomy and subtotal gastrectomy were performed under a tentative diagnosis of right renal cell carcinoma and early gastric cancer. The excised specimen macroscopically demonstrated a yellowish mass in the middle portion and microscopically revealed many lymphocytes and few neutrophils, macrophages or foam cells. The patient was diagnosed as tumor-forming type of chronic pyelonephritis. Such obvious inflammatory findings very rarely exist in the tumor-forming type of chronic pyelonephritis. Therefore, caution should be exercised in the differential diagnosis between this disease and renal cell carcinoma.