Two Cases of Cutaneous Metastasis from Small Cell Lung Cancer / 대한피부과학회지

ABSTRACT

The frequency of metastasis to the skin from lung cancer is 1-12%. The incidence of cutaneous metastasis was high in patients with large-cell lung cancer, whereas squamous cell and small-cell lung cancer showed the least tendency to extend to cutaneous sites. Adenocarcinoma was intermediate in the tendency to metastasize in the skin. Histological findings of small-cell lung cancer show solid, tumor cell nests composed of neoplastic cells with large, round nuclei. So, it is often difficult to distinguish small-cell lung cancer from other poorly differentiated small-cell tumors, such as Merkel cell carcinoma, metastatic carcinoid, lymphoma, etc. We report here two cases of skin metastasis from small-cell lung cancer. Case one was a 74-year-old man presenting with a single, round, dome-shaped nodule on the alar nasi which had been present for 1 month. The second case was a 73-year-old man who had found three, non-tender, freely movable subcutaneous nodules on the abdomen 3 days before. Both cases were diagnosed as small-cell lung cancer. On histopathological examination of the skin lesions, we could observe that small round to oval cells with dark staining nuclei and scant cytoplasms were arranged in anastomosing trabecular streams through the dermis, separated by strands of connective tissue in both cases. In the first case, the tumor cells were positive to cytokeratin and NSE, negative to neurofilament antiagen and LCA.