Imaging description

A two-year-old boy presented with leukocoria (= white pupil). Ophthalmoscopy demonstrated large masses in both globes. A CT scan showed extensive calcifications of both lesions (Fig. 1.1a). An MR scan better delineated the contrast-enhancing masses in the bilateral globes, both of which demonstrated extraocular extension (Fig. 1.1b).

An axial contrast-enhanced MR scan of the brain in a different patient with retinoblastoma shows an additional, inhomogeneously enhancing mass in the pineal gland (Fig. 1.2).

Importance

Retinoblastoma is the most common intraocular tumor of childhood, occurring in one in 15000 to 20000 live births. Approximately 200 new cases a year are diagnosed in the USA. The disease presents in infancy or early childhood, with the majority of cases diagnosed before the age of 4 years.

A second primary malignancy, most commonly a midline intracranial tumor, is found in 5–7% of patients with bilateral retinoblastoma. Often, these other brain tumors occur weeks or months after the diagnosis of the retinoblastoma, with a median interval of 21 months. Trilateral retinoblastoma has traditionally been nearly universally fatal, although a recent study suggests that intensive chemotherapy may improve survival. Early detection is likely an important factor in survival.