自然破裂をきたした腎癌の1例 : 本邦68症例の統計学的検討

Abstract

53歳男.右腰背部痛で右腎被膜下血腫を指摘された.超音波で右腎を圧排する8.0×6.7×6.2のiso-low echoicの不均一なmassを認め, CTでは右腎上極～下極に被膜下血腫を, 下極に6×3cmの被膜外への突出を認めた.MRIでは右腎被膜下にT1強調像で一部斑状の高信号を伴う低信号を認め, Gd-DTPAでは造影されず, 下極には4×3cmの不規則な造影を認めた.右腎癌の自然破裂を疑い, 手術を行った.後腹膜・Gerota筋膜下に血腫は認めず, 周囲の癒着も軽度で, 腎動静脈を一塊として結紮切離し, 右腎を適除した.摘出臓器は925g, 18.5×12×12cmであった.血腫は肥厚した腎被膜を越えず, 腎実質を覆うように存在した.割面で下極に1cm大の白色腫瘤を認めた.病理組織学的にはrenal cell carcinoma, clear cell carcinoma, grade 3, INFγ(infiltrating type), pTla, pV0で, stage Iと診断した.術後インターフェロンα300万単位を週2回投与し, 14ヵ月経過で再発・転移はない

A 53-year-old man presented to our hospital as an emergency admission with sudden right flank pain. No examinations using contrast media could be performed due to allergies. Abdominal plain computed tomography and ultrasonography revealed right peri-renal hematoma, but causes were unknown. Magnetic resonance imaging (MRI) contrasted with gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) revealed right spontaneous rupture of renal cancer and radical nephrectomy was performed. The surgical specimen displayed renal subcapsular hematoma, and histopathology revealed renal clear cell carcinoma, grade 3, INF gamma, pT1a, pV0. The patient was well and without local recurrence or distant metastasis at 14 months postoperatively. Spontaneous rupture of renal cancer is uncommon, and our case is the 68th reported in Japan. MRI is useful for diagnosis and surgical intervention is recommended. Analysis by the Kaplan-Meier method showed good prognosis in spite of spindle cell carcinoma and advanced disease (stage IV).