Renal Pelvis Epidermoid Cyst Mimicking Staghorn Calculus: Successful Treatment with Percutaneous Approach (PCN).

Abstract

BACKGROUND: Renal pelvis epidermoid cysts are extremely rare and often misdiagnosed as stones or tumors. Only one previous case has been treated via the percutaneous approach (PCN). CASE PRESENTATION: A 67-year-old diabetic female on Empagliflozin presented with imaging suggestive of a staghorn calculus. During Percutaneous Nephrolithotomy (PCNL), whitish keratinous material was found in the renal pelvis along with a small obstructing stone. All material was evacuated through the Amplatz sheath. Urine culture was negative. Histopathology confirmed an epidermoid cyst. Postoperative CT scan at one month showed complete resolution. DISCUSSION: Epidermoid cysts can mimic staghorn calculi radiologically. A Fungal ball was initially suspected due to diabetes and SGLT2 inhibitor therapy, but radiopacity, negative culture, and histology ruled this out. PCNL served as both a diagnostic and therapeutic procedure, preserving renal function. CONCLUSION: Renal pelvis epidermoid cysts should be considered in the differential diagnosis of opaque pelvic lesions. PCNL is a minimally invasive, kidney-preserving treatment that can be performed as a renal-sparing procedure.