Anaplastic Kidney Wilms Tumor

**Semantic type:** Neoplastic Process

**Definition:** Wilms tumor of the kidney characterized by the presence of nuclear anaplasia. Anaplasia is defined by the presence of all of the following: multipolar polyploid mitotic figures, marked nuclear enlargement, and hyperchromasia. When anaplasia is diffuse, it is associated with an unfavorable clinical outcome.

**Synonyms:** - Anaplastic Renal Wilm's Tumor - Anaplastic Renal Wilms Tumor - Anaplastic Renal Wilms' Tumor