Post-irradiation malignant fibrous histiocytoma of the larynx: A case report with an unusual metastatic spread pattern.

We report a case of a laryngeal malignant fibrous histiocytoma (MFH) that showed an uncommon clinical behavior. This tumor occurred in a 70-year-old male patient 5 years after radiation treatment for laryngeal squamous cell carcinoma, and unusual metastases were spread unusually to the pleural cavity. The interval between the end of radiotherapy and the onset of MFH can be justified by the development of laryngeal stenosis by fibrotic tissue as a late complication of radiotherapy. Laryngeal fibrosis after radiotherapy probably triggered the MFH. Neither computed tomography nor magnetic resonance imaging differentiate between fibrotic tissue and MFH, and only repeated biopsy was definitive to give us the correct diagnosis.