Inflammatory myofibroblastic tumor of larynx: a benign lesion with variable morphological spectrum

Abstract 

Inflammatory myofibroblastic tumor is a recently characterized lesion, composed of exuberant myofibroblastic proliferation and an inflammatory component. Its etiology remains controversial, as to whether this represents a benign tumor with limited potential to recur or progress. Exaggerated response to trauma or infection has also been implicated. Only a few cases of laryngeal inflammatory myofibroblastic tumor have been described in English after it has been assigned the new name. The prototype lesion, inflammatory pseudotumor, has been best described in association with the lung but has also been reported involving various organs. We report 2 additional cases with a considerable variation in the presentation and histology of the lesion, thus expanding the morphological spectrum of the entity. Both lesions appeared aggressive in clinical presentation. One case had relatively more pleomorphic appearance and increased mitotic rate. Both lesions were surgically resected, and complete voice preservation was achieved. No postoperative complications or recurrence were noticed. This uncommon neoplasm may appear clinically as a large infiltrating mass and may be mistaken as a malignant growth. Conservative resection of the tumor may provide a cure with adequate voice preservation.

Keywords: Inflammatory myofibroblastic tumor, Inflammatory pseudotumor, Plasma cell granuloma, ALK1, Immunohistochemical studies