Background: Inflammatory myofibroblastic tumor (IMT) is an intermediate malignancy characterized by myofibroblast proliferation and inflammatory cell infiltration. The most common sites of origin of IMT are the lungs, abdominal pelvis, and retroperitoneum, with the orbits being rare. Here, we report a case of a patient with IMT of the orbit.
Case: A 46-year-old female patient visited a local ophthalmologist with a chief complaint of diplopia. Orbital mass was identified, and the patient was referred to the Department of Ophthalmology of Kyushu University Hospital. A reddish mass under the right conjunctiva and 35×20×15 mm spindle-shaped mass inferiorly in the right orbit causing eye movement disorder were observed on imaging at the initial examination. Biopsy of the subconjunctival tumor revealed spindle-shaped cell proliferation with inflammatory cell infiltration. The proliferating cells were immunohistochemically positive for anaplastic lymphoma kinase (ALK), α-smooth muscle actin (α-SMA) and desmin; hence, we diagnosed the patient with IMT. The patient underwent conjunctival resection and a surgical approach under nasal endoscopy, and the mass was completely removed. No recurrence was observed after 24 months of surgery.
Conclusion: When nonepithelial tumors of the orbit are suspected, the possibility of IMT should be considered.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 126: 820-826, 2022.