INFLAMMATORY MYOFIBROBLASTIC TUMOR OF THE LARYNX - A CLINICOPATHOLOGIC STUDY OF 8 CASES SIMULATING A MALIGNANT SPINDLE CELL NEOPLASM

Background. Inflammatory myofibroblastic tumors of the larynx are unco mmon lesions that easily may be misinterpreted as malignant epithelial or mesenchymal spindle cell neoplasms. Methods. Eight cases of laryng eal inflammatory myofibroblastic tumors were identified from the files of the Otolaryngic Tumor Registry-Armed Forces Institute of Pathology , Clinical records and follow-up were available in all cases, The ligh t microscopic features (hematoxylin and eosin and special histochemica l stains) were evaluated in all cases; immunohistochemical analysis wa s performed in the seven cases with available paraffin blocks; in four cases ultrastructural analysis was done. Results. The patients includ ed five males and three females ranging in age from 19-69 years (media n, 59 years). Presenting symptoms included hoarseness, dysphonia, or r apidly progressive strider with the duration of symptoms ranging from 10 days to 4 months. The most common site of involvement was the true vocal cord. The lesions appeared as polypoid or pedunculated masses. H istologically, the cellularity of the lesions varied, consisting of sp indle-shaped to stellate cells with no consistently discernible growth pattern, in a fibromyxoid stroma that included a mixed inflammatory c ell infiltrate. Features suggesting a malignant cellular infiltrate we re not present. The spindle-shaped cells had consistent immunoreactivi ty with vimentin, muscle specific actin, and smooth muscle actin. Ultr astructurally, intracytoplasmic microfilaments were identified. In sev en of the patients, conservative but complete excision of the lesion w as curative; these patients have been free of disease over periods ran ging from 12 to 36 months. In one patient, the lesion recurred twice o ver a 2-year period and ultimately required a total laryngectomy. This patient died of unrelated causes. Conclusions. Inflammatory myofibrob lastic tumors of the larynx are unusual benign proliferative lesions. Conservative surgical management is advocated and is curative. Recurre nce is rare, but metastases disease or death attributable to these les ions is not.