Background
Inflammatory myofibroblastic tumors (IMFTs) of the larynx are rare. We report the clinical presentation, histomorphology, and new molecular findings of 2 cases.
Methods
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.
Results
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.
Conclusion
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. © 2009 Wiley Periodicals, Inc. Head Neck, 2009