Multiple Primary Melanomas in a Young Patient

A 45-year-old HIV-negative Caucasian man with no reported past medical history was referred to our Department with a large (7 cm in diameter) oozing nodule on the occipital region of the scalp with spontaneous periodical bloody or purulent discharge. The lesion had appeared over a period of six months, had an irregular color, non-specific dermoscopic features, and resembled squamous cell carcinoma. The physical examination revealed three more atypical melanocytic lesions (on the abdomen, back, and buccal mucosa), and multiple swollen occipital, postauricular, as well as superficial and deep cervical lymph nodes. After clinical evaluation, the patient reported having another in situ melanoma (submammary region) excised 7 years ago. All the lesions were excised and sent for histopathologic examination, which was compatible with primary cutaneous melanoma. Total body computed tomography revealed the presence of multiple visceral metastases, and the patient was referred to an oncologist. He did not consent to proceed to genetic testing. The occurrence of multiple primary melanomas (MPM) is a rare but recognized phenomenon. The estimated incidence of a second primary tumor ranges from 0.2% to 8.7% in large retrospective reviews. While 63% to 88% of patients with MPM are reported to have two primary tumors, the occurrence of more than four primary melanomas is considered exceedingly rare (1-2). Whether the presence of multiple primary melanomas is a function of increased genetic susceptibility of the individual, consistent exposure to a common exogenous promoter of malignancy, or a combination of these two factors remains to be elucidated. These patients should undergo intensive dermatologic screening for the rest of their lives and should consider genetic testing.