LAUSR

Melanoma of unknown primary (MUP) was originally defined in 1963 by Dasgupta et al. as melanoma in the subcutaneous tissue, lymph nodes or visceral organs without the presence of cutaneous, ocular or mucosal primary [1]. The incidence of MUP is reported as between 1 and 8% of all melanomas [2]. The median age of presentation of MUP is between 40 and 50 years of age [3]. The male to female ratio is approximately 2:1 [4]. Sixty per cent of MUP presents in the lymph nodes — most frequently axillary lymph nodes, followed by cervical, inguinal and parotid lymph nodes [4]. Other sites of presentation include the subcutaneous tissue, lung, gastrointestinal tract and brain [5]. The American Joint Committee on Cancer (AJCC) classifies MUP presenting in a lymph node or subcutaneous tissue as stage three and MUP presenting within a visceral organ as stage four [4].