Malignant Peripheral Nerve Sheath Tumour in the Setting of a Rare Germline BAP1 Disease Causing Variant presenting as a Metastatic Melanoma Mimic

A 47-year-old male presented with a 9-year history of a subcutaneous swelling on his right, his initial diagnosis was a stage IV metastatic melanoma deposit on the right wrist originating from a pT4a BAP1 inactivated primary melanoma on the back. Due to the unusual nature of the presentation further input from a specialist skin cancer multidisciplinary team with an interest in BAP1 tumour predisposition syndrome (BAP1-TPDS) led to a revised diagnosis of a Malignant Peripheral Nerve Sheath Tumour (MPNST) on the wrist.