Classification of renal cell cancer

Classification

Three main histopathological RCC types have been described in the 2004 WHO classification and modified by International Society of Urological Pathology (ISUP) Vancouver Classification.

• clear cell (ccRCC)
  • make up about 70% of all cancers of the kidney
  • commonly affects patients in their sixth to seventh decades of life but may occur in all age groups
  • tumor cells have clear cytoplasm and are arranged in compact nests, sheets, alveolar, or acinar structures separated by thin-walled blood vessels
    
    
• papillary (pRCC - type I and II)
  • second most common type of RCC and accounts for 10-15% of RCCs
  • has a better prognosis (5-year survival around 90%)
  • two subtypes are recognised according to histology - type I & type II
    • type 1patients have a better prognosis than type II patients
      
      
• chromophobe (chRCC)
  • accounts for 5% of RCC
  • cells contain largely empty cytoplasm
  • typically have characteristic perinuclear clearing
  • has the lowest risk of developing metastasis

Other renal tumors which include a variety of uncommon, sporadic, and familial carcinomas constitute the remaining 10-15 % of renal cortical tumours.

• rare tumors of the nephron and collecting system
  • occurs in less than 5% of cases
  • e.g. - collecting duct carcinoma, renal medullary carcinoma, and urothelial carcinoma
  • highly distinct disease entities that bear little resemblance to RCCs.
• premalignant and benign lesions arising in the kidney
  • include angiomyolipomas, oncocytomas (1,2,3)

Reference:

• (1) Jonasch E, Gao J, Rathmell WK.Renal cell carcinoma. BMJ. 2014;349:g4797.
• (2) Ljungberg B et al. EAU guidelines on renal cell carcinoma: 2014 update. Eur Urol. 2015;67(5):913-24.
• (3) Dutcher JP. Steven C. Campbell, Brian I. Rini (eds). Renal cell carcinoma: clinical management (current clinical urology series), series editor: Eric A. Klein, Humana Press, 2013, 362 pp. Med Oncol. 2013;30(2):510.