New and emerging renal tumour entities

In this review, we discuss new and emerging renal cell carcinoma (RCC) entities, including anaplastic lymphoma kinase (ALK) RCC, oncocytic variant of chromophobe RCC, atrophic kidney-like renal tumour, biphasic alveolosquamoid RCC, tubulocystic RCC, thyroid-like follicular carcinoma of the kidney, succinate dehydrogenase-deficient RCC, Birt–Hogg–Dubé syndrome-associated renal tumour, hereditary leiomyomatosis/renal cell carcinoma associated RCC, tuberous sclerosis-associated RCC, PTEN hamartoma tumour syndrome, clear cell papillary RCC, acquired cystic disease-associated RCC, Xp11.2 RCC, t(6;11) RCC and renal hemangioblastoma. These tumours have clinical, pathological and genetic features distinct from other common RCCs and therefore are important to recognize. Some of them have been recognized as distinct histological subtypes in the 2016 World Health Organization Classification. However, further studies are needed to elucidate their clinicopathologic features and molecular mechanisms.