Metanephric adenofibroma are seen in children and young adults and metanephric stromal tumor are primarily seen in younger children. BRAF V600E mutations are present in most of the cases, and rarely other codon V600 mutations.  Immunohistochemistry (IHC) for BRAF V600E may be helpful, but not in the BRAF variants. ¹ See also details on Metanephric Tumors described in the WHO 2022 Urinary and Male Genital Tumours.