Inflammatory pseudotumors of the head and neck in pathology-proven cases.

The purpose of this case series is to characterize the CT and MRI features of pathology-proven inflammatory pseudotumors in the head and neck. Our search identified three orbital, one maxillary sinus, and one skull base inflammatory pseudotumor. All of the lesions demonstrated some degree of infiltrative features on imaging. On CT, all of the orbital inflammatory pseudotumors were of homogeneous soft tissue density. One of the orbital inflammatory pseudotumors demonstrated bone erosion and two others demonstrated stranding of the orbital fat. The maxillary sinus lesion initially appeared aggressive with bone erosion and orbital invasion. Calcifications were identified in the dural inflammatory pseudotumor. Among the lesions that were given contrast during CT or MRI. All exhibited some degree of enhancement. The two pseudotumors that underwent MRI were isointense on T1 and T2, with scattered areas of low signal. The orbital inflammatory pseudotumors underwent orbitotomy. However, the maxillary sinus and skull base lesions regressed with steroid therapy. Inflammatory pseudotumors of the head and neck regions typically manifest as enhancing soft tissue masses associated with infiltrative changes. Despite their sometimes-aggressive appearance, these lesions may respond well to steroid treatment. Imaging plays an important role in diagnosing and following inflammatory pseudotumors.