Multifocal and microscopic chromophobe renal cell carcinomatous lesions associated with ‘capsulomas’ without FCLN gene abnormality

Abstract

Chromophobe renal cell carcinoma (RCC) accounts for approximately 5% of renal epithelial neoplasms. Multiple and/or bilateral chromophobe RCCs in an individual are generally rare but frequently occur in patients with Birt-Hogg-Dubé syndrome (BHDS) and in patients with tuberous sclerosis complex (TSC). The responsible genes in both BHDS and TSC act as tumor suppressors. Therefore, it seems that some genetic backgrounds are required for the generation and progression of multiple chromophobe RCCs. Here, we report a case of multiple and bilateral chromophobe RCCs along with several small-sized capsular angiomyolipomas known as 'capsulomas' in a 39-year-old woman who had neither a particular medical history nor specific gene mutation. There has been no report of sporadic multiple chromophobe RCCs and 'capsulomas' developing in a patient without genetic features, having potential for novel genetic variation.