Primary malignant melanoma of the lung: a case report of a rare tumor and review of the literature

Primary malignant melanoma of the lung (PMML) is a rare malignancy that exhibits aggressive behavior and has a very poor prognosis. We are reporting on a case of PMML in an otherwise healthy 22-year-old Caucasian male with no significant past medical history and an unremarkable family history. The patient initially presented with a 2-month history of a cough and an unexplained 22-lb weight loss. His initial chest X-ray demonstrated opacification of the right lower lobe (RLL) of his lung and a subsequent computerized tomography scan (CT scan) of his lung revealed a large mass occupying most of his RLL (Figure 1). The patient subsequently underwent a bronchoscopy with endobronchial ultrasound. Biopsies revealed a poorly differentiated carcinoma. A positron emission tomography with low dose CT scan was performed per protocol and revealed an intensely hypermetabolic tumor with no evidence for lymphatic disease or extra-thoracic spread. The patient underwent a surgical exploration and a right lower lobectomy with a thoracic lymphadenectomy. The pathology including immunohistochemical stains demonstrated a malignant melanoma with no lymph node involvement. A physical examination including ophthalmic, mucosal, and skin examinations revealed no evidence for an extra-thoracic site of the disease. The patient had negative margins for resection and did not receive any adjuvant therapy and is alive and well with no evidence for recurrence 3years after the resection.