Chondrosarcomatous Differentiation in a Large Malignant Melanoma of the Scalp.

. Divergent differentiation in malignant melanoma is a rare phenomenon, which can lead to delayed diagnosis or misdiagnosis, impacting upon patient treatment and outcome, as well as the understanding of tumour behaviour. . We present the case of a large long-standing tumour on the scalp of a 72-year-old female patient, which when excised and examined histologically was revealed to be a nodular malignant melanoma displaying chondrosarcomatous differentiation. Foci suggestive of lentigo maligna were also present. Rapid metastatic spread of the tumour was observed shortly after the primary resection. . To our knowledge, this is the first reported case in the literature of chondrosarcomatous differentiation in a lentigo maligna melanoma. The clinical and histopathological details and images of this case are presented alongside a discussion regarding such tumours and patterns of similar tumour behaviour.