Radiologic features of fumarate hydratase-deficient renal cell carcinoma

Objective To investigate the clinical and imaging features of fumarate hydratase-deficient renal cell carcinoma (FH-RCC) in order to improve clinical understandings of this disease. Methods A retrospective study was conducted on all pathologically confirmed FH-RCC patients in our hospital from 2020 to 2022. Their clinical information, pathological data and imaging features were collected and analyzed with descriptive study. Results There were 6 pathologically confirmed FH-RCC patients (8 tumors) enrolled, and they were 4 males and 2 females, at an age of 27~48 year. Imaging Results showed that 62.5% (5/8) tumors were cystic solid lesions and 37.5% (3/8) were pure solid lesions. One lesion showed mixed signal on MRI and limited diffusion of the solid component of the lesion on diffusion-weighted imaging. Enhanced scanning displayed 71.4% (5/7) had progressive enhancement of the solid portion of the lesion, and 75.0% (6/8) had invasion of the renal sinus, including 1 case with simultaneous invasion of the adrenal gland. Retroperitoneal lymph node metastasis was 66.7% (4/6) cases on first examination. All 6 patients were treated with surgical resection, and 66.7% (4/6) had metastases at 2 to 21 (6.8±7.8) months of follow-up. Conclusion Radiological features of FH-RCC were mainly cystic solid occupancy with a thin cystic wall and progressive enhancement of the solid part after contrast enhancements.