Giant acral melanoma on the left thumb of a korean patient.

The acral regions of the limbs of Asians are predisposed to develop malignant melanoma, but giant-sized acral melanoma has not been previously reported in the Asian population. Giant-sized melanoma implies aggressive tumor invasion and so it is more difficult to achieve a therapeutic cure. A 56-year-old woman presented with a giant acral melanoma of the left thumb with concomitant bone destruction and axillary lymph node metastasis. The initial lesion was a subungual black macule on the left thumb that had grown into a giant 7.0x4.0x3.5 cm-sized melanoma over a 3 year period. The left thumb was amputated and the axillary lymph nodes were completely dissected. During the ensuing 3 months, she underwent adjuvant treatment with interferon-alpha-2a. The interesting feature of this case is that the large melanoma mass of this patient, which was accompanied with adjacent bone destruction and lymph node metastasis, had developed rapidly from a small black macule in the nail matrix, and this black macule was suspected to be a subungual melanoma.