A rare case of combined small-cell lung cancer with unusual soft tissue metastasis.

Combined small-cell lung carcinoma (SCLC) is a rare tumor. We report a case of combined SCLC of the lung, including adenocarcinoma and spindle-shaped cell tumor, with an unusual initial presentation. The patient suffered from a right shoulder mass, subsequently undergoing biopsy. A lung nodule was noted later after complete examination. The diagnosis turned out to be combined cell carcinoma with three different components (small-cell carcinoma, adenocarcinoma, and spindle-shaped cell tumor) after examination upon total removal of the lung nodule by lobectomy. In addition to the rarity of the three components in such a tumor, soft tissue metastasis also made it an unusual case.