A 58-Year-Old Woman Undergoing Mammographic Screening, Breast Neurofibroma
Breast neurofibromas in the context of Neurofibromatosis Type 1 (NF1) 1. Cause and Etiology Neurofibromatosis Type 1 (NF1) is a genetic disorder caused by mutations in the NF1 gene on chromosome 17q11.2 , which encodes neurofibromin , a tumor suppressor protein. Neurofibromin negatively regulates the RAS/MAPK signaling pathway , and its loss leads to increased cellular proliferation. Breast neurofibromas in NF1 are: Benign peripheral nerve sheath tumors involve the intradermal or subcutaneous nerves of the breast tissue. Considered a cutaneous manifestation of systemic NF1. May arise from terminal cutaneous branches of peripheral nerves within the breast. Rare compared to other typical locations (e.g., trunk, limbs, face), but when present, usually occur in subareolar or subcutaneous tissue . 2. Pathophysiology The formation of neurofibromas in the breast in NF1 follows the same mechanism as...