The presenting symptoms and signs of intracranial tumors diagnosed before the age of 2 years in 21 children treated at the University Hospital of Wales are reported from the Department of Child Health, Cardiff, UK. Nine of the tumors were supratentorial and 12 were infratentorial. The commonest tumor types were astrocytoma in 5, ependymoma 4, and medulloblastoma in 4. The interval between onset of symptoms and diagnosis ranged from less than 1 day to 7 months. Nine had symptoms for at least 3 months before diagnosis. CT or MRI and biopsies were performed in all cases. The commonest presenting symptoms were vomiting in 9, and unsteadiness in 8. The commonest presenting sign was enlarged head circumference in 16. Meningitis was suspected initially and a spinal tap was performed before neuroimaging in 5 of the cases with raised intracranial pressure. Only one had neck stiffness. One received antituberculous treatment before a diagnostic CT was prompted by a rapidly deteriorating state. Multiple diagnoses were considered other than tumor and the significance of the head enlargement was not recognized in cases diagnosed late. 
COMMENT. The diagnosis of intracranial tumor presenting in infancy may be difficult. A high index of suspicion is advisable in infants presenting with vomiting, unsteadiness, and enlarged head circumference. CT or MRI should precede consideration of spinal tap in infants with the above presenting features, especially if the diagnosis of meningitis is clinically indefinite. Not only is a spinal tap hazardous in the presence of raised intracranial pressure but a CSF pleocytosis and elevated protein, frequently found with tumors, may be misleading and lead to incorrect treatment and delay. Seizures are an uncommon presenting symptom in this age group of brain tumor patients whereas in children of all ages, seizures occur in 17% of cases, especially with supratentorial tumors. See Progress in Pediatric Neurology II, 1994, pp344-5.