Subungual Melanoma is Not so Rare: Report of Four Cases from India.

Subungual melanoma (SUM) is an uncommon form of acral melanoma that arises within the nail matrix. The incidence for acral melanomas is similar worldwide, however, the proportion is higher in dark-skinned individuals. The subungual form represents approximately 2% of cutaneous non-sun-induced melanomas in the western world and up to 75% in Africans, 10% in Japanese, and 25% in the Chinese. No specific figures are available from the Indian subcontinent; however, the authors could trace three anecdotal case reports published over the last two decades. A general reluctance to biopsy a nail lesion to confirm the diagnosis may be contributing to the missed diagnosis. We report four cases of SUM of the big toenails seen over a period of 2.5 years. They were three women and one man with an age ranging from the 4th to 7th decade and disease duration of 6-18 months. The lesion involved the big toe in all and two patients had liver and lymph node metastasis at the time of presentation. Awareness among dermatologists regarding clinical manifestations, high index of suspicion for acral pigmented lesions, and nail bed biopsy may help in the early diagnosis and management and can prevent mortality.