The relative value of neural imaging studies in the diagnosis of a neonatal astrocytoma associated with tuberous sclerosis is reported from the Departments of Neurosciences, Pediatrics, and Pathology, University of California, San Diego, CA. The infant was hypotonic at birth and had poor respiratory effort. Apgar scores were 3/8. Motor examination revealed decreased tone in proximal upper extremities and neck. Deep tendon reflexes were generally exaggerated and plantar responses were extensor bilaterally. Wood’s lamp examination was equivocal. There was no family history of tuberous sclerosis or epilepsy and the parents showed no neurocutaneous stigmata. An echoencephalogram revealed a large mass in the left lateral ventricle arising from the left caudate nucleus and obstructing the foramen of Monroe. The study was consistent with an intraventricular tumor rather than a hematoma. The MRI revealed a large irregular lobulated mass believed to be a tumor arising from the corpus callosum, possibly a lipoma. The CT revealed a nonenhancing, hyperdense mass in the left frontal horn interpreted as an intraventricular hemorrhage. A CT-guided needle biopsy of the mass showed gemistocytic cells resembling large reactive astrocytes. A cardiac echocardiogram revealed multiple nodules in the intraventricular septum, consistent with multiple rhabdomyomas. Funduscopic exam revealed two small retinal hamartomas in the right eye. Ultrasound of the kidneys was negative. At eight weeks of age the infant had developed multiple hypopigmented macules on trunk and extremities. 
COMMENT. The interpretation of the echoencephalogram was closer to the correct diagnosis than that of the MRI and CT. Even without the needle biopsy of the mass the diagnosis of tuberous sclerosis and associated tumor may have been suspected and almost certainly determined by the echocardiogram and cardiac rhabdomyomas. Echoencephalogram may be the diagnostic study of choice in newborns. The MRI picture is atypical showing decreased signal intensity on T2-weighted imaging and increased signal intensity on T1-weighted studies.