Differences in the clinical courses of pediatric and adult pilocytic astrocytomas with progression: a single-institution study

Pilocytic astrocytoma (PA) is a World Health Organization grade I neoplasm that generally follows a benign course. However, in some patients, PA exhibits an aggressive clinical course. Here, we examined the clinical course of pediatric and adult PAs with progression at a single institution. Between 1995 and 2013, 39 patients with PA were treated. Nineteen were pediatric patients (mean age, 12 years; range, 1-17 years) with a male-to-female patient ratio of 10:9, while 20 were adults (mean age, 36.4 years; range, 19-65 years) with a male-to-female ratio of 9:11. We analyzed and compared tumor location, extent of tumor resection, adjuvant treatment, and clinical course in all patients. In the 19 pediatric patients, tumors were located in the cerebellar vermis, cerebellar hemisphere, optic pathways plus hypothalamus, hypothalamus, brainstem, and the temporal lobe in 6 (31.6 %), 5 (26.3 %), 3 (15.8 %), 2 (10.5 %), and 2 (10.5 %) patients and 1 (5.3 %) patient, respectively. The mass was totally, subtotally, or partially resected in 11 (57.9 %), 2 (10.5 %), and 4 (21.1 %) patients, respectively; biopsies were performed in 2 (10.5 %) patients. Immediate postoperative adjuvant treatment was carried out in 6 patients. Tumor progression was detected in 3 patients at 3.0, 4.6, and 5.2 years after treatment, respectively, without significant symptoms. In the 20 adult patients, tumors were located in the cerebellar hemisphere, cerebellar vermis, hypothalamus, brainstem, cerebral hemisphere, and lateral ventricle in 5 (25 %), 4 (20 %), 3 (15 %), 3 (15 %), 3 (15 %), and 2 (10 %) patients, respectively. The mass was totally, subtotally, or partially resected in 11 (55 %) and 6 (30 %) patients and 1 (5 %) patient, respectively; biopsies were performed in 2 patients. Immediate adjuvant treatment was carried out in 2 patients. Progression was detected in 3 patients at 0.3, 0.9, and 2.5 years after treatment, respectively, with progressive neurologic symptoms. There was one case of disease-related mortality during follow-up among the adult patients. Most of the PA cases evaluated in this study were benign. However, tumor progression in adult PAs followed a more aggressive clinical course than those in pediatric PAs.