Retinoblastoma

Image 1

Image 1

Clinical History:
A 15 month old female infant.

Diagnosis:
Retinoblastoma

MR Technique:
Axial 2.5 mm pre-contrast SE T1- and FSE T2-weighted images are presented, acquired at 1.5 T. Sequence parameters were TR/ TE = 500/10 and 5800/104.5 respectively.

Imaging Findings:
There are three distinct lesions involving the right globe (with only the largest of the three illustrated). This lesion demonstrated prominent enhancement (not illustrated). Additionally, there is a large area of abnormal signal involving the entire vitreous of the left globe. There is a small fluid-fluid level posteriorly. There is also a large mass (which appears as two separate components on the images presented), isointense to the mass in the right globe on T2-weighted images on which it is easily identified, involving the left globe. This also demonstrated prominent enhancement (not illustrated). A pertinent negative (indicating the lack of disease extension), there did not appear to be any enhancement posterior to either globe within the intraconal fat and no abnormal enhancement was noted involving the optic nerves. Additionally, there was an 8 mm, prominently enhancing, soft tissue mass involving the pineal area (not illustrated). In a child of this age, with bilateral lesions involving the globes, and a lesion of the pineal, the imaging findings are consistent with a trilateral retinoblastoma (which was confirmed by histopathology).

Retinoblastoma is a malignant retinal neoplasm. In trilateral disease, there are bilateral ocular tumors and a midline lesion, with the pineal the most common location (a suprasellar lesion is much less common). Retinoblastomas are typically calcified (by CT), and are unilateral in 75% of cases. They demonstrate on MR moderate to marked enhancement. Being soft tissue lesions, they are higher SI than the vitreous on T1-, and lower SI than the vitreous on T2-weighted scans.