Squamous cell carcinoma of lung associated with osteoclast-like giant cells: report of a case.

Resently, we treated a 69-year-old patient with squamous cell carcinoma of lung with osteoclast-like giant cells which were similar with the giant cell tumor of bone. The clinical and pathological characteristics of this case were presented, and the literatures were reviewed. The tumor differed histologically from the pleomorphic carcinoma, which occurs most commonly in the lung and showed diverse pleomorphic manifestation with benign looking osteoclast-like multinucleated cells and bizarre giant cells. In addition, undifferentiated carcinoma with a sarcoma-like appearance containing small areas of papillary adenocarcinoma was evident in the tumor. Histological features and immunohistochemical staining could be helpful in differential diagnosis.