Three children, aged 4, 5, and 9 years, had an insidious onset of ataxia. Magnetic resonance imaging (MRI) showed hydrocephalus and countless foci of high T2 signal coating the cerebellum, basilar cisterns, brainstem, and fourth ventricle. Similar lesions were present in the spinal cord. Symptoms were relatively mild given the massive tumor burden. Biopsies were composed of superficially infiltrating cells with oligodendroglioma-like features (perinuclear halos and cytologic monotony) and microcysts. Classical cytogenetic analysis of 2 cases showed normal karyotypes. Chromosome fluorescence in situ hybridization revealed 1p36 deletion with intact 19q in 2 cases and no abnormality in one. A similar combination of clinical, MRI, and histopathologic findings has been reported previously in 10 other cases. The pathologic findings suggest a glioma with diffuse or multifocal superficial origin and do not correspond to a described entity in the current World Health Organization (WHO) classification of brain tumors.

Hemangiomas, which are usually found in the skin, are extremely rare in an intradural location. An unusual case of capillary hemangioma intimate to the cauda equina is discussed. This entity has not previously been reported in the pediatric or adolescent population to the best of our knowledge, although it has been reported in adults.

Astroblastoma is a very rare primary glial tumor occurring in children and young adults that is almost exclusively supratentorial in location. We report an extremely unusual presentation of a densely calcified posterior fossa astroblastoma with disseminated spinal and supratentorial metastasis. The mass exhibited neoplastic bone formation, which has not been reported, although calcifications are commonly seen in astroblastomas. A companion case of a low-grade astroblastoma that demonstrated classic histologic features but nonspecific and atypical imaging findings is also included. These cases expand the imaging and pathologic spectrum of this controversial tumor that shows highly variable biologic behavior and is difficult to distinguish from ependymoma.