Collecting duct carcinoma may cause diagnostic difficulties with pRCC and FH-deficient RCCs [40], but the usual pattern of tubular structures, infiltrative growth with desmoplasia and localization of these tumors in the renal hilus usually creates more challenges in the differential to urothelial carcinoma of the renal pelvis [41]. The gene discussed is FH; the disease is urothelial carcinoma.