Although we report only 4 cases, the striking similarity of clinical presentation and roentgenographic findings in these cases, and those reported by others, causes us to strongly consider this entity a distinct neuroendocrinologic and roentgenographic syndrome. These patients suffer from double, possibly simultaneously arising, atypical teratomas and may present with symptoms referable to one or other of the lesions. However, the anterior lesion usually produces symptoms first and characteristically there is insidious, but progressive, onset of diabetes insipidus and hypopituitarism. The posterior lesion characteristically leads to abnormal eye signs consisting of loss of pupillary light reflex and loss of upward gaze (Parinaud’s syndrome). In addition, if the lesion is large enough, aqueduct obstruction and hydrocephalus occur. The anterior lesion, if large enough, may encroach upon the optic nerves and produce visual field deficits.