Metastatic melanoma presenting as a malignant peripheral nerve sheath tumour

This is a report of a metastatic melanoma presenting clinically as a soft tissue mass and histologically being diagnosed as a malignant peripheral nerve sheath tumour. In this case the metastatic melanoma was preceded by a primary cutaneous melanoma in a similar anatomical region. Histologically the tumour was characterised by a malignant-appearing Spindle cell proliferation, arranged in fascicules. There was no evidence of connection to a nerve, co-existent neurofibroma or stigmata of neurofibromatosis. This presentation is only infrequently mentioned in the literature and heterogeneity can make clinical and histological diagnosis of metastatic melanoma problematic. It can easily be misinterpreted without effective clinico-histological correlation, making a good working relationship between Clinician and Histopathologist essential for correct diagnosis.