Incidental identification of a multilocular cystic renal neoplasm of low malignant potential: A rare case report

Abstract Multilocular cystic renal neoplasms of low malignant potential (MCRNLMP), which account for <1% of renal neoplasms, predominantly affect middle-aged males and are often asymptomatic and incidentally identified through imaging. This report presents a case involving a 49-year-old man with an incidentally detected Bosniak III cystic renal lesion measuring 5.7 cm in the left kidney. Preoperative imaging evaluation suggested the lesion’s complexity, guiding the decision toward implementing a nephron-sparing surgical approach. The patient, therefore, underwent robot-assisted partial nephrectomy using the Da Vinci surgical system, achieving complete tumor resection with minimal blood loss and no complications. Histopathological and immunohistochemical analyses revealed clear cells lining the thin fibrous septa without significant atypical features, confirming MCRNLMP. Despite the critical role of imaging in lesion characterization, definitive differentiation between MCRNLMP and clear cell renal cell carcinoma remains challenging due to overlapping imaging and histological features. This case highlights the importance of advanced imaging modalities in improving the diagnostic accuracy when computed tomography findings are inconclusive. Given the excellent prognosis associated with MCRNLMP, nephron-sparing surgery remains the gold-standard diagnostic and treatment approach. This report emphasizes the need for a multidisciplinary approach integrating clinical evaluation, advanced imaging, and precise histopathological assessment to optimize outcomes in patients with rare renal conditions.