[A CASE OF FUMARATE HYDRATASE (FH)-DEFICIENT RENAL CELL CARCINOMA SUSPECTED OF HEREDITARY LEIOMYOMATOSIS RENAL CELL CARCINOMA].

We experienced a case of fumarate hydratase (FH) -deficient renal cell carcinoma (RCC) suspected of hereditary leiomyomatosis renal cell carcinoma (HLRCC) and herein report our findings. A 42-year-old man with an unremarkable medical history was referred to our hospital with an initial impression of renal cancer, cT3aN2M0. He underwent a right radical nephrectomy with lymph node dissection and showed a pathological diagnosis of FH-deficient RCC, pT3aN2. Clinicopathologic features indicated the possibility of HLRCC; however,-associated RCC. genetic testing showed negative for pathogenic FH mutation.HLRCC is an autosomal dominant condition caused by an FH gene mutation on chromosome 1q43. It is also a syndrome that develops in the smooth muscles of the skin and uterus, and has a renal cancer risk of 10-16%. HLRCC-associated RCC tends to metastasize early and shows poor prognosis. In FH-deficient RCC, the possibility of HLRCC-related RCC should be considered; thus, if patients fulfill the clinical diagnostic criteria, genetic counseling and screening of HLRCC are needed. Even if genetic testing does not confirm HLRCC, FH-deficient RCC still has a poor prognosis and careful follow-up is required.