Spindle cell carcinoma of the larynx.

The clinicopathological features of 14 laryngeal neoplasms consisting of spindle-shaped cells are presented. Light microscopy showed a variety of morphological patterns from that of pleomorphic sarcoma and fibrosarcoma to more loose vascular patterns. Immunohistochemistry revealed that the spindle-shaped cells had a positive keratin immunoreactivity in 8 of 14 cases, and also that some cases had a dual expression of keratin and vimentin filaments. Electron microscopy showed that spindle-shaped cells had epithelial ultrastructures. The results support the hypothesis that the spindle cell carcinomas are true carcinomas with mesenchymal metaplasia and that the spindle-shaped cells are part of the neoplasm and not benign, reactive fibroblasts. These lesions occurred mainly on the true vocal cords in elderly patients. The neoplasms were nearly all polypoid, and many also ulcerated. There is no significant difference in clinical behaviour between laryngeal spindle cell carcinomas and ordinary squamous cell carcinomas of the larynx, and the same treatment policy is therefore advocated. Being polypoid and therefore able to be surgically removed with relative ease, they may even present a more favourable clinical course.