A case of multiple primary cutaneous melanoma

According to Western reports, there's a 1?8% possibility that multiple melanomas can occur in one individual. Although two melanomas occurring simultaneously or metachronously on different areas of the skin in a patient are rare and this has not yet been reported in the Korean dermatological literature, there could be two possible explanations. One is cutaneous recurrence/metastasis from a primary cutaneous melanoma (PCM) and the other is development of another new PCM, and this is the so called multiple primary cutaneous melanoma (MPCM). We report here on a 72-year-old man who presented with a subungual melanoma on the right thumb (T2bN0M0, duration: 3 years) and the other melanoma was on the right sole (TisN0M0, duration: 10 years). We could not find any evidence of recurrence/metastasis on the physical examinations and various imaging studies. Pathological differences were shown between the 2 melanomas and, more importantly, the differences were anatomically irrelevant. So, we diagnosed the lesions as MPCM instead of recurrence/metastasis of PCM or other possibilities.