Amelanotic melanoma of the skin – detailed review of the problem

Abstract

Background Malignant melanoma (MM) of the skin accounts for about one per cent of all malignancies in humans. Amelanotic melanoma is a rare tumour, diagnosed in eight per cent of all melanomas. Aims The study aimed to analyse our clinical experience with amelanotic MM of the skin and the statistical data from a retrospective five year analysis of pigmented and amelanotic types of skin melanoma. Furthermore, we compare our results to those from other teams' studies. To reach the corresponding in-depth conclusions. Methods The study included 151 patients with malignant melanoma of the skin, diagnosed and treated at Dr. Georgi Stranski University in Pleven, Bulgaria, between 2012 and 2016. All the patients signed informed consent forms. Results Of the 151 patients we studied, 14 (9.3 per cent) were diagnosed with amelanotic melanoma. The average Breslow thickness in patients with amelanotic MM was 4.2mm, while in pigmented MM patients it 2.1mm. Local recurrence rates (35.7 per cent) were higher in patients with amelanotic melanoma. Distant metastases were found in 39 of all tested patients with melanoma. Of the 14 patients with amelanotic MM, eight had such metastases. Conclusion Amelanotic melanoma was diagnosed too late. Local recurrences were six times as many as the ones diagnosed in pigment melanoma. Distant metastases were twice as many, and mortality rates were three times higher.