WHO classification of tumors of the kidney

The World Health Organization (WHO) classification of tumors of the kidney is the most commonly used pathologic classification system for such disorders. The current revision, part of the 4 edition of the WHO series, was published in 2016 as part of the WHO Classification of Tumors of the Urinary System and Male Genital Organs . It is heavily based upon the International Society of Urological Pathology (ISUP) Vancouver classification of renal neoplasia of 2013 and supercedes the 2004 WHO classification. The 2016 version is reflected in the article below.

Classification

Renal cell tumors
Metanephric tumors
Nephroblastic and cystic tumors occurring mainly in children
Mesenchymal tumors occurring mainly in children
Mesenchymal tumors occurring mainly in adults
Mixed epithelial and stromal tumor family
Neuroendocrine tumors
Miscellaneous tumors
  • renal hematopoietic neoplasms
  • germ cell tumors of the kidney
Metastatic tumors

Changes from prior versions

Several but not all familial forms of renal cell carcinoma have been subsumed into the corresponding histology, which can also arise sporadically (e.g. clear cell renal cell carcinoma in von Hippel-Lindau disease, chromophobe renal cell carcinoma in Birt-Hogg-Dubé (BHD) syndrome).

The entity previously known as multilocular cystic renal cell carcinoma or multilocular clear cell renal cell carcinoma is now described as multilocular cystic renal neoplasm of low malignant potential in recognition of the low incidence of recurrence and metastasis.

The size cutoff for papillary adenoma was increased from ≤0.5 cm to ≤1.5 cm.

Cystic nephroma has been divided into the adult and pediatric forms. The adult form is included along a spectrum of mixed epithelial and stromal tumors.

Renal carcinoids have been redesignated well-differentiated neuroendocrine tumors of the kidney and placed in a group with small cell neuroendocrine carcinomas, large cell neuroendocrine carcinomas, and paragangliomas (extra-adrenal pheochromocytoma).

Several entities are newly established:

See also