Multidetector CT Characteristics of Fumarate Hydratase-Deficient Renal Cell Carcinoma and Papillary Type II Renal Cell Carcinoma

Abstract

Objective To investigate the multidetector computed tomography (MDCT) features of fumarate hydratase-deficient renal cell carcinoma (FH-deficient RCC) with germline or somatic mutations, and compare them with those of papillary type II RCC (pRCC type II). Materials and Methods A total of 24 patients (mean ± standard deviation, 40.4 ± 14.7 years) with pathologically confirmed FH-deficient RCC (15 with germline and 9 with somatic mutations) and 54 patients (58.6 ± 12.6 years) with pRCC type II were enrolled. The MDCT features were retrospectively reviewed and compared between the two entities and mutation subgroups, and were correlated with the clinicopathological findings. Results All the lesions were unilateral and single. Compared with pRCC type II, FH-deficient RCC was more prevalent among younger patients (40.4 ± 14.7 vs. 58.6 ± 12.6, p < 0.001) and tended to be larger (8.1 ± 4.1 vs. 5.4 ± 3.2, p = 0.002). Cystic solid patterns were more common in FH-deficient RCC (20/24 vs. 16/54, p < 0.001), with 16 of the 20 (80.0%) cystic solid tumors having showed typical polycystic and thin smooth walls and/or septa, with an eccentric solid component. Lymph node (16/24 vs. 16/54, p = 0.003) and distant (11/24 vs. 3/54, p < 0.001) metastases were more frequent in FH-deficient RCC. FH-deficient RCC and pRCC type II showed similar attenuation in the unenhanced phase. The attenuation in the corticomedullary phase (CMP) (76.3% ± 25.0% vs. 60.2 ± 23.6, p = 0.008) and nephrographic phase (NP) (87.7 ± 20.5, vs. 71.2 ± 23.9, p = 0.004), absolute enhancement in CMP (39.0 ± 24.8 vs. 27.1 ± 22.7, p = 0.001) and NP (50.5 ± 20.5 vs. 38.2 ± 21.9, p = 0.001), and relative enhancement ratio to the renal cortex in CMP (0.35 ± 0.26 vs. 0.24 ± 0.19, p = 0.001) and NP (0.43 ± 0.24 vs. 0.29 ± 0.19, p < 0.001) were significantly higher in FH-deficient RCC. No significant difference was found between the FH germline and somatic mutation subgroups in any of the parameters. Conclusion The MDCT features of FH-deficient RCC were different from those of pRCC type II, whereas there was no statistical difference between the germline and somatic mutation subgroups. A kidney mass with a cystic solid pattern and metastatic tendency, especially in young patients, should be considered for FH-deficient RCC.

The clinicopathologic and molecular features, and treatment outcome of fumarate hydratase-deficient renal cell carcinoma: a retrospective comparison with type 2 papillary renal cell carcinoma

“…This study analyzed the baseline characteristics, immunohistochemical features, gene mutation and prognosis of 16 FH-dRCC patients and compared with those of 44 patients with T2 pRCC. Many of our findings support the conclusions described in previous studies [ 14 , 18 ], including that FH-dRCC tend to present at a younger age than T2 pRCC (median age of 43.5 years), behave aggressively (50% of cases presented at tumor stage pT3a or higher) and more common in males. Lymph node and distant metastases were more frequent in FH-dRCC, as shown in the present study, metastases are commonly observed in the LNs, liver, lungs, bone and peritoneal seeding, and portend a poor prognosis.…”

“…As found in our study, the prognosis of FH-dRCC is worse than T2 pRCC. The proportion of patients with distant metastasis was higher in our study (81.3% vs. 13.6%) than in the study by Yang, while that of LNs metastasis was lower (37.5% vs. 6.8%) [ 18 ]. Since FH-dRCC is significantly more invasive than T2 pRCC, RN and lymph node dissection are recommended.…”

“…After the release of 2016 WHO classification criteria, studies have documented FH deficiency in many T2 pRCC cases [14,15]. Recent investigations into the images of papillary type II HLRCC-associated RCC and FH-dRCC have identified some distinct features that may help clinical practitioners in differentiating FH-dRCC from T2 pRCC and pathologists in IHC or even gene sequencing [16][17][18]. However, few studies have systematically compared the clinical features and prognostic outcomes of patients with FH-dRCC and T2 pRCC.…”

Case report: Ultrasonographic findings of retroperitoneum and abdominal wall metastases of renal cell carcinoma with FH gene deletion

“…Yang et al. ( 11 ) investigated the multidetector computed tomography (MDCT) features of FH-d RCC, and Nikolovski et al. ( 12 ) evaluated the imaging features of FH-d RCC on CT, MRI, and FDG PET.…”