Malignant melanoma is known to spread by local extention, by the lymphatics by the blood stream. Direct invasion of the bone from a cutaneous melanoma is unknown. Hence, this case is presented in view of its rarity. A 75-year-old Caucasian lady presented with a small papillary lesion in the region of a recurrent chronic cellulitis on the lower third of the lateral aspect of the right leg. Histopathology diagnosed the lesion as locally advanced malignant melanoma. Radiological investigations by X-ray and magnetic resonance imaging revealed malignant infiltration of the tibia in its mid and lower third with two soft tissue metastatic masses adjacent. Histology following amputation confirmed malignant melanoma with cranial resection margin involvement. She underwent a further above-knee amputation followed by chemotherapy. The patient recovered from the amputation but subsequently died 6 months later due to bronchopneumonia from lung metastasis.
Keywords: Bone tumor; direct invasion; malignant melanoma; metastatic melanoma.