Primary melanomas of the lung are rare malignant tumors of uncertain histogenesis believed by some to arise from melanocytic metaplasia of the bronchial respiratory epithelium or from primitive displaced melanocytic cells from the foregut, during the process of embryogenesis. Melanomas show no gender predilection and most occur between the ages of 29 and 80 years. Clinical symptoms are related to obstruction with dyspnea or hemoptysis predominating. Little is known about the radiographic appearance of primary melanomas of lung. Some present as pleural effusions of unknown origin. Metastatic melanoma usually presents as multiple tumor masses but may on occasion be single.