Imaging characteristics of rare renal cell carcinoma subtypes: diagnostic challenges and clinical implications

The molecularly defined renal cell carcinomas (RCC) are named based on characteristic molecular alterations or familial predisposition syndromes, which were usually diagnosed at advanced stages and contribute significantly to renal cancer-related mortality. The diagnosis of molecularly defined renal cancer relies on advanced histological experiments, thus reliable preoperative prediction can reduce unnecessary costs. We reviewed the literature about the molecularly defined RCCs to summarize radiological features, that could assist in preoperative diagnosis. Currently some specific imaging features could help assist in diagnosing molecularly defined RCCs, for example magnetic resonance spectroscopy for fumarate hydratase–deficient RCC. However, current research is based on small sample sizes, and we need larger cohorts for analysis in the future. 1 The molecularly defined renal tumors are defined by characteristic molecular alterations or familial predisposition syndromes. 2. The molecularly defined renal tumors are mainly diagnosed by immunohistochemistry and advanced molecular tests. 3. Special imaging features could assist in diagnosing molecularly defined renal tumors preoperatively.