Soft tissue masses of the chest wall and axilla: Has metastatic melanoma been considered?

Isolated axillary and chest wall soft tissue masses are an uncommon presentation of metastatic cancer. The authors present three patients in whom malignant melanomas metastatic to these sites had been misdiagnosed, leading to inappropriate oncologic treatment planning in all three cases. The presumed diagnoses, even after fine-needle aspiration or trucut biopsies, were soft-tissue sarcoma (n = 2) and undifferentiated breast cancer (n = 1). The combination of taking a thorough history and performing proper immunohistochemical analysis of the biopsy material would have suggested the presence of malignant melanoma in all cases. As the disease appeared locoregionally limited in all patients, radical surgical resection with extended lymphadenectomy was performed without significant dysfunction of the upper extremity. One patient agreed to postoperative immunotherapy with interferon-alpha. Two patients are currently alive 17 and 14 months after operation. One patient was found to have systemic recurrence at 5 months, one experienced two isolated local recurrences in a prior operative site that were amenable to reresection and presently has no evidence of disease 12 months after resection, and one patient remains free of disease at 14 months. Clinical presentation, suggested diagnostic workup, and therapeutic implications are discussed to avoid misdiagnoses in this setting of possible clinical presentations of metastatic melanoma.