Renal granuloma misdiagnosed as renal papillary carcinoma: a case report

The imaging appearance of renal granuloma is very similar to that of a renal tumor. Granulomatous lesions usually do not require surgical treatment, while kidney tumors typically necessitate surgical removal. The diagnosis of renal granuloma typically relies on the history of bacillus Calmette-Guérin perfusion and the position of the renal pelvis in the image (malignant tumors usually destroy or compress the surrounding renal pelvis). However, in this case, the patient has no history of bacillus Calmette-Guérin perfusion, making the diagnosis more challenging. The ultrasound and enhanced CT findings were consistent with renal papillary carcinoma. Laparoscopic partial nephrectomy was performed, revealing degeneration and necrosis of the renal cortex and formation of granulomas. The imaging diagnosis of renal granuloma is difficult. Ultrasound-guided biopsy may be a preferable method to avoid unnecessary surgery.