case_images: PMC9062903_01
case_images: Serial images of noncontrast axial computed tomography scans of the region below the orbital floor (a), at the level of the lower bulb (b), and at the level of the equator of the bulb (c) showing a mass lesion in the anterior part of the left orbit that is isodense relative to the extraocular muscles and located in the inferior (a), inferolateral (b), and posterior (c) aspects of the bulb (arrow). a (inferior) c (superior).
case_images: SNI-13-130-g001.jpg
case_images: PMC9062903_01_SNI-13-130-g001.jpg
case_images: F1
case_images: The mass was isodense relative to the extraocular muscles and located in the inferior, inferolateral, and posterior aspects of the bulb [Figure 1].
case_images: Serial images of the axial T1- (a-c) and T2-weighted (d-f) magnetic resonance imaging (MRI) and postcontrast fat suppression T1-weighted coronal MRI (g-i) showing the left orbital lesion (arrow) that is well-demarcated and separate from the inferior rectus muscle, appearing isointense both on T1- and T2-weighted imaging, and intensely enhanced after intravenous infusion of gadolinium. a (inferior) c (superior); d (anterior) f (posterior); g (anterior) i (posterior).
case_images: SNI-13-130-g002.jpg
case_images: PMC9062903_01_SNI-13-130-g002.jpg
case_images: F2
case_images: On magnetic resonance imaging (MRI), the mass was well-demarcated and separate from the inferior rectus muscle, appeared isointense on both T1- and T2-weighted imaging, and was intensely enhanced after intravenous infusion of gadolinium [Figure 2].
case_images: Photomicrographs of the resected specimens showing sheet-like proliferation of small round cells with a high nuclear-to-cytoplasmic ratio and lacking findings of atypia (a and b). They are positively stained for CD20 (c) and CD79a (d) markers specific for B-lymphocytes, as well as CD3 (e) and CD5 (f) markers specific for T-lymphocytes. HE: Hematoxylin and eosin stain.
case_images: SNI-13-130-g003.jpg
case_images: PMC9062903_01_SNI-13-130-g003.jpg
case_images: F3
case_images: T-lymphocytes [Figure 3].
case_images: (a-c) Serial images of coronal T2-weighted MRI performed 3 months after surgery showing a remarkable improvement of the swelling of the inferior oblique muscle (arrow). a (anterior) c (posterior).
case_images: SNI-13-130-g004.jpg
case_images: PMC9062903_01_SNI-13-130-g004.jpg
case_images: F4
case_images: MRI performed 3 months after surgery showed remarkable regression of the swollen IObM [Figure 4].