Conventional, diffusion, and permeability MR findings in ocular medulloepithelioma

To describe the neuroradiological features of intraocular medulloepithelioma.

We retrospectively analyzed the clinical, histopathological, and MRI data of five children with medulloepithelioma. In addition to conventional images, DWI was performed in four patients and mean ADC was calculated; this was limited to the technique of this cohort of patients. DCE was performed in all patients. This is the first paper that presents diffusion and perfusion characteristics of medulloepithelioma.

Four tumors were malignant teratoid variants, two non-teratoid variants. Tumors were hyperintense on T1-weighted images and hypointense on T2-weighted images. Calcifications were detectable in two out of five tumors. Cavities were detectable in three out of five tumors. All tumors showed some degree of enhancement. The mean ADC of all four patients was 1.156 ± 242.75 × 10^-3 mm²/s. Mean ktrans, Ve, Kep, TME, AUC, SER, and peak enhancement were 0.082 ± 0.054, 0.19 ± 0.076, 0.31 ± 0.084, 0.97 ± 0.0784, 1.22 ± 0.81, 67.34 ± 31.7, and 14.84 ± 7.34 respectively. TICs showed a very high ratio of slow increase, > 50% persistence and some degree of wash out. Teratoid variants showed higher K-trans, AUC, VE, TME, and persistent TIC pattern than non-teratoid ones, while plateau pattern ratio was lower.

Conventional MR findings were similar to previously reported cases. Mean ADCs were moderately high. TICs showed slow increase and presence of wash out. K-trans, AUC, VE, and TME were higher in teratoid variants. Permeability parameters in differential diagnosis with lesions mimicking medulloepithelioma need further investigations.