Pulmonary involvement of malignant melanoma: thin-section CT findings with pathologic correlation

The purpose of this study was to characterize the thin-section computed tomography (CT) findings of primary and secondary pulmonary malignant melanoma and to correlate them with the histopathologic features.

Patients were identified from a pathologic registration system database through a query for patients with diagnosed primary or secondary pulmonary melanoma who had undergone surgical resection. A total of 19 pulmonary malignant melanomas, including one primary and 18 secondary involvements, from 10 patients were enrolled into this study. The patients consisted of 3 men and 6 women, with a mean age of 55 years (range, 28 to 71 years). Thin-section CT findings evaluated by consensus between two radiologists were compared with the histopathologic specimens.

Tumor size ranged from 4 to 62 mm (mean, 19 mm) on thin-section CT images. Four characteristic patterns including solitary or multiple solid nodule, endobronchial lesion, cavitary nodule, and nodule with ground-glass attenuation were disclosed by correlation between thin-section CT and pathologic findings. The most common thin-section CT finding was a solid nodule with a well-defined, smooth margin (n=14). Endobronchial lesions were seen in one primary and one secondary involvement (n=2). Less common CT findings were cavitary nodule (n=1) and nodule with ground-glass attenuation (n=1).

Primary and secondary pulmonary malignant melanomas show various patterns of involvement on thin-section CT.