Laryngeal inflammatory myofibroblastic tumors: Different clinical appearance and histomorphologic presentation of one entity.

Abstract

Inflammatory myofibroblastic tumors (IMFTs) of the larynx are rare. We report the clinical presentation, histomorphology, and new molecular findings of 2 cases. Paraffin-embedded specimens were stained immunohistochemically (eg, vimentin, AE1/3, Alk-1, smooth muscle [sm-]actin, p53, Rb1, immunoglobulin G4 [IgG4]). Epstein-Barr virus-encoded RNA (EBER) in situ hybridization and HHV8-polymerase chain reaction (PCR) were done. Comparative genomic hybridization (CGH) was performed. Case 1 was that of a 56-year-old man with an infiltrating plasma-cell-rich tumor (Alk-1-, sm-actin+). Plasma cells were strongly positive for IgG4. CGH was unsuspicious. Case 2 was that of a 34-year-old woman with an exophytic tumor (Alk-1+). CGH revealed losses on 13q14-22. The few plasma cells were negative for IgG4. The proliferation (Ki67) was low in both cases. Different types of IMFTs may exist and could indicate different therapeutic strategies. Alk-1-positive cases with only scattered inflammatory cells could represent the neoplastic variant, whereas cases rich in plasma cells could be associated with IgG4 sclerosing diseases.