Rapidly enlarging intraocular inflammatory myofibroblastic tumor in an adult

Intraocular inflammatory myofibroblastic tumor (IMT) is an extremely rare entity, and its clinical characteristics, immunopathological features, and optimal management remain insufficiently defined. A 57-year-old man presented with visual field defect in his right eye. Ophthalmic examination revealed an intraocular mass associated with retinal detachment. Magnetic resonance imaging and N-isopropyl-p-[123I] iodoamphetamine single photon emission computed tomography (¹²³I-IMP-SPECT) demonstrated mild uptake suggestive of a malignant intraocular tumor, although differentiation from malignant melanoma remained difficult. The tumor exhibited rapid enlargement over a three-month period, leading to loss of light perception. Following enucleation, histopathological evaluation revealed proliferation of spindle-shaped tumor cells accompanied by prominent inflammatory cell infiltration. Immunohistochemical analysis demonstrated diffuse and strong positivity for anaplastic lymphoma kinase (ALK). Fluorescence in situ hybridization (FISH) for ALK rearrangement yielded equivocal results. Based on an integrated assessment of clinicopathological and immunohistochemical findings, a final diagnosis of intraocular IMT was deemed most appropriate. Intraocular IMT should be considered in the differential diagnosis of rapidly progressive intraocular tumors. Accurate diagnosis requires comprehensive clinicopathological correlation, including detailed immunohistochemical evaluation. Given the potential aggressive clinical behavior despite its inflammatory nature, timely surgical intervention may be necessary for both diagnostic confirmation and disease control.