Rate of spontaneous hemorrhage in histologically proven cases of pilocytic astrocytoma.

OBJECT: Spontaneous intracerebral hemorrhage is an uncommon but recognized initial presenting sign of both primary and metastatic brain tumors. The rate of tumor-related intracranial hemorrhage is variably reported from <1 to 14.6%. Hemorrhage in primary gliomas occurs in 3.7-7.2% of gliomas, mainly in glioblastoma muliforme and oligodendroglioma with low-grade astrocytomas accounting for <1%. Hemorrhage associated with pilocytic astrocytomas (PAs) is only sporadically reported. The authors report on a series of patients in whom PAs presenting as hemorrhages prompted them to examine the incidence of bleeding in these tumors.
METHODS: Cases involving a confirmed tissue diagnosis of PA from 1994-2005 were reviewed retrospectively. The authors included only patients with evidence of hemorrhage on computed tomography and/or magnetic resonance imaging seen prior to biopsy or resection and in the absence of trauma or other vascular pathological entities.
RESULTS: In 138 patients with histologically proven PAs, the mean age at diagnosis was 23 years. In 11 patients (8%; 5 male and 6 female) there was evidence of hemorrhage at presentation. There were no locations more susceptible to hemorrhage than any other, although no bleeding occurred within the cerebellum. All but 1 patient was treated with a gross-total resection.
CONCLUSIONS: Hemorrhage in association with PAs likely results from the frequently observed abnormal vasculature in these tumors, occurs with a greater frequency than previously thought, and should be considered in the differential diagnosis of spontaneous intracerebral hemorrhage.