Spindle cell carcinoma of the gingiva: report of an autopsy case.

An autopsied case of an 80-year-old man with spindle cell carcinoma of the gingiva is reported. The tumor was polypoid and mostly composed of a sarcomatous proliferation of spindle cells with a small focus of squamous cell carcinoma at the stalk portion. The carcinoma metastasized to a cervical lymph node, lungs and pleura with extension to the diaphragm. In the metastatic lymph node, the squamous cell component was more prominent than the spindle cell one, while only anaplastic pleomorphic carcinoma cells were found in the lungs. The spindle or anaplastic cells were immunohistochemically positive for vimentin and carcinoembryonic antigen (CEA) but not for other epithelial antigens. We have concluded that the sarcomatoid component arose from the oral squamous cell carcinoma by a metaplastic process. This is the first case report of an oral spindle cell carcinoma examined by autopsy.