Abstract

Renal papillary adenomas, typically benign and under 15 mm, are found more frequently in patients with hereditary renal carcinoma or end-stage renal disease. Renal adenomatosis, the presence of numerous adenomas within one or both kidneys, is rare. We report an unusual case involving simultaneous hybrid carcinomas (papillary type I and clear cell) and multiple adenomas in a patient with renal adenomatosis, contributing to the understanding of the mechanisms of neoplastic progression within this pathological context. A 63-year-old male with a history of benign prostatic hyperplasia presented with incidental findings of multiple cystic and solid renal lesions in both kidneys during an ultrasound examination. Some of these lesions appeared suspicious for malignancy, prompting surgical intervention. Initially, a left partial nephrectomy was performed, followed by a right radical nephrectomy one year later to manage the complex presentation. Comprehensive histopathological and immunohistochemical analyses were conducted on the excised specimens to classify and characterize the tumors. This case illustrates an unusual coexistence of multiple renal neoplasms, including hybrid carcinomas and papillary adenomas, which may indicate an underlying genetic predisposition, potentially involving the MET and VHL pathways. Such genetic interactions may contribute to the multifocal nature of tumor development in renal adenomatosis. This finding underscores the importance of detailed genetic and histopathological profiling to enhance our understanding of biological behavior and the potential progression of these tumors. Comprehensive profiling in similar cases could also offer valuable insights into personalized treatment approaches and long-term management.