Solitary pulmonary metastasis from malignant melanoma of the bulbar conjunctiva presenting as a pulmonary ground glass nodule: Report of a case

We herein report a case of solitary pulmonary metastasis from malignant melanoma that presented as a pulmonary ground glass nodule. A 57-year-old man who had undergone resection of a malignant melanoma of the right bulbar conjunctiva at the age of 51 was referred to our hospital for management of ground glass opacity in his left lung. Because radiological examination suggested the nodule was an adenocarcinoma in situ, computed tomography (CT) follow-up was planned. CT examination performed nine months later showed that the nodule had grown from 6 mm to 8 mm. Moreover, CT performed one and a half years after first detection revealed that the nodule had grown up to 10 mm. The patient, therefore, underwent partial resection of the lung for diagnosis and treatment. Pathological examination of the resected specimen revealed atypical cells with melanin granules proliferating in a lepidic-like fashion. The cells were positive on S-100 staining, indicating a pulmonary metastasis from malignant melanoma. Thus, metastatic tumors from malignant melanoma can present as ground glass opacities.