TWO YOUNG ADULT siblings independently developed similar neurological
complaints that included headaches, photophobia, nausea, and intermitt
ent lancinating facial pains. Magnetic resonance imaging revealed four
th ventricular lesions that required surgery in both patients. A patho
logical review revealed subependymomas with virtually identical histol
ogical features. The clinical features and common pathological finding
s of both patients suggest that familial subependymomas may have a mal
developmental origin with genetic implications.