Clinical, pathological, and radiological features of the cystic renal lesions

Abstract

Cystic lesions of the kidney represent a heterogeneous group of conditions ranging from non-neoplastic processes to benign and malignant neoplasms. With the widespread use of cross-sectional imaging, these lesions are detected with increasing frequency, often incidentally during radiologic evaluation. The Bosniak classification system remains the primary radiologic framework for estimating malignancy risk and guiding management decisions for cystic renal masses. However, imaging findings alone are frequently insufficient for definitive diagnosis, and accurate classification often requires integration with gross and histopathologic evaluation. In this review, we provide an integrated overview of cystic renal lesions with emphasis on their clinical, radiologic, gross, histopathologic, and immunohistochemical characteristics. The spectrum includes nonneoplastic entities to benign and malignant neoplasms. In addition, tumors that are typically solid but may demonstrate prominent cystic change are discussed, highlighting the importance of including these entities in the differential diagnosis when evaluating complex cystic renal masses. Understanding the morphologic spectrum and recognizing key diagnostic features are essential for distinguishing benign cysts from cystic neoplasms and for avoiding both underdiagnosis and overtreatment. Radiologic-pathologic correlation and a structured diagnostic approach are critical for accurate classification and optimal patient management. Continued refinement of imaging criteria and improved multidisciplinary collaboration will further enhance the diagnostic evaluation and clinical management of cystic renal lesions.