IgG4 Related Sclerosing Inflammatory Pseudotumor Simulating Cholesteatoma Of The Temporal Bone

Abstract

Introduction Sclerosing inflammatory pseudotumor of the temporal bone is a rare fibro-inflammatory, benign albeit locally aggressive pathological entity. Case Report We report a case of Sclerosing inflammatory pseudotumor of the temporal bone, simulating a cholesteatoma. A 61-year-old female presented with right otalgia, hearing loss, facial pain and imbalance. Ear microscopy revealed a pulsatile mass in the external auditory canal. HRCT temporal bone and MRI reported soft tissue mass in the right middle ear and mastoid air cells, causing attenuation of the ossicles with erosion through the tegmen and mastoid cortex. The patient underwent canal wall down tympanomastoidectomy. The histopathology with immunohistochemistry was consistent with IgG4 related sclerosing inflammatory pseudotumor. Discussion This case report explores the similarities as well as the clinical differences between cholesteatoma and IgG4 sclerosing inflammatory pseudotumor of temporal bone, along with the diagnostic and treatment challenges. It is often mistaken for neoplasm or cholesteatoma, hence should be considered as a differential diagnosis.