Neurotropic malignant melanoma of right temple with orbital metastasis: a clinicopathological case report

Abstract

A case is reported of neurotropic melanoma developed from a superficial spreading melanoma with minimal cytological deviation, situated in the right temple. The nine-year course was clinically characterised by local recurrences, involvement of the orbit and the parotid region via neurogenic invasion, and systemic metastases to lung, seventh rib, and the brain. The histopathology was characterised by fascicles of dysplastic spindle cells, neuroid arrangement in loose fibrillary matrix, and peri- and intraneural permeation of the nerve trunks. Despite minimal atypism the neoplasm metastasised and had a fatal outcome. The spindle cell component of the neurotropic melanoma lacked melanogenesis; Fontana stains were negative. As previously demonstrated, the histogenesis of the neurotropic melanoma is possibly a Schwann cell differentiation of the dysplastic atypical melanocytes, as shown by the positive reactions to Bodian's stain.