Metastatic amelanotic melanoma simulating giant-cell tumor of bone.

A case of metastatic malignant melanoma simulating a giant cell tumor of bone is reported. This case typifies the diversity of expression of malignant melanoma. Osteoclast-like giant cells were present only in the femoral head metastasis and were not present in the primary lesion. The giant cell component may be reflective of an inherent and indiscriminant expression which may be seen in a variety of neoplastic bone lesions.