Inflammatory Myofibroblastic Tumor of the Temporal Bone: A Case Report

Inflammatory myofibroblastic tumor (IMT) is classified as an uncommon intermediate-grade neoplasm that rarely involves the temporal bone.We report a case of a 23-year-old female who presented with right aural fullness and pain.Computed tomography findings showed a 1.6-cm well-circumscribed soft tissue mass in the superior mastoid portion of the right temporal bone, with bone destruction extending to the tegmen mastoideum.Magnetic resonance imaging (MRI) showed T1 isointensity and predominantly mild T2 hyperintensity with internal hypointense areas.Two months later, preoperative MRI showed interval enlargement of the mass to 2.4 cm, with heterogeneous enhancement and adjacent dural thickening and enhancement.The biopsy results showed proliferation of the spindle cells with inflammatory cell infiltration, and the tumor cells were positive for anaplastic lymphoma kinase (ALK), supporting the diagnosis of IMT.Histopathologic evaluation of the resection specimen revealed collagen-rich fibrous components and myxoid stroma, mixed inflammatory infiltrates, hemorrhage, hemosiderin deposition, and focal dural invasion without brain involvement.The patient remained recurrence-free five years after surgery.The heterogeneous T2 signal may reflect the underlying histologic heterogeneity of the tumor.IMT may be considered in young patients with a bone-destructive temporal bone mass showing heterogeneous T2 signal, contrast enhancement, and interval enlargement.Furthermore, histopathologic evaluation is essential to reach a definitive diagnosis.