Inflammatory myofibroblastic tumor of paranasal sinuses.

Inflammatory myofibroblastic tumors IMTs are clinico-pathologically distinctive but biologically controversial entities; they rarely affect the head and neck region and usually follow a benign clinical course after radical excision. We reviewed the literatures of IMTs and present a rare case of IMT arising from the maxillary paranasal sinus of an 11-year-old girl. Moreover, we elaborate on the morpho-immunophenotypic characteristics of this lesion. Microscopic examination revealed a spindle cell proliferation set in a highly vascular stroma with numerous inflammatory cells. Tumor cells were immunoreactive for vimentin, and smooth muscle actin, negative for desmin, S-100, p53, Cyclin D1, and bcl-2. The potential neoplastic nature of this lesion was substantiated by the strong diffuse immuno-expression of ALK-1 protein, a marker that has been linked to neoplastic transformation. The lesion was excised completely by a CO2 LASER as a new treatment modality and the patient manifested no evidence of disease recurrence at 10-months recall.