Multiple angiomyolipomas mimicking metastases of concurrent clear cell renal cell carcinoma

Introduction: Concurrence of clear cell renal cell carcinoma and angiomyolipoma is quite rare. We report a case of large localized clear cell renal cell carcinoma with concurrent multiple angiomyolipomas mimicking lymph node metastases.

Case presentation: A 60-year-old woman presented with general malaise, weight loss, and intermittent fever. Computed tomography scan demonstrated an 8-cm mass in the left kidney, enlarged para-aortic lymph nodes, and small renal nodules adjacent to the main tumor. She was diagnosed preoperatively as having clear cell renal cell carcinoma (cT3a) with multiple para-aortic lymph node metastases, and underwent laparoscopic radical nephrectomy and dissection of the para-aortic lymph nodes. Pathologically, the main tumor was diagnosed as clear cell renal cell carcinoma. By contrast, both the para-aortic lymph nodes and nodules were diagnosed as lipid-poor angiomyolipomas.

Conclusion: With the expanding first-line use of molecular targeted therapy for metastatic renal cell carcinoma, nephrectomy may be avoided by overdiagnosis. Upfront nephrectomy can avoid overdiagnosis and undertreatment of nonmetastatic renal cell carcinoma.

Keywords: clear cell renal cell carcinoma; kidney cancer; lipid‐poor angiomyolipoma; multiple angiomyolipomas.