A Rare Case of Malignant Melanoma of the Cervical Lymph Nodes with an Unknown Primary Origin; A Case Report.

Metastatic malignant melanomas to the neck of an unknown primary origin are very rare in Japan. A 76 year-old woman presented to our hospital complaining of a neck tumor on the left side. Cervical CT scanning revealed three swollen lymph nodes. A biopsy was performed, and the histopathological findings demonstrated that metastatic malignant melanomas had developed in the three cervical lymph nodes as large as 35mm in diameter. Subsequent staging examinations which were carried out included inspection of the whole skin and adjacent mucosa, CT scanning of the brain, neck and chest, abdominal ultrasound and CT scanning, a bone scan and Ga scintigraphy. We performed a radical left neck dissection, and a total of 60 Gy of irradiation therapy was delivered after the surgery. No recurrence has been observed for 15 months after the patient's first visit. Our report reviews this rare case of metastatic malignant melanoma to the left cervical lymph nodes of an unknown primary origin.