LG-02CHALLENGES IN THE MANAGEMENT OF HYPOTHALAMIC JUVENILE PILOCYTIC ASTROCYTOMA

INTRODUCTION: Juvenile pilocytic astrocytoma is a relatively common pediatric intracranial tumor. In rare cases it arises from the region of the hypothalamus and optic pathways, with extensive anterior skull base involvement. Optimum treatment strategies have not been fully defined. We describe 2 cases in which different approaches were undertaken. METHOD: Patient 1 presented at age 1 year with visual and endocrine disturbance, macrocrania, and diencephalic syndrome. A large enhancing mass involving the anterior skull base and exerting mass effect on the brainstem was seen on MRI. This patient underwent surgery for tissue diagnosis, relief of mass effect on the brainstem, and alleviation of obstructive hydrocephalus. A subtotal resection was achieved. Patient 2 presented at age 5 years with subacute headaches, and recent nystagmus and ataxia. Endocrine evaluation was normal. Brain MRI showed a similar anterior skull base enhancing mass and associated hydrocephalus, although with less mass effect on the brainstem. The patient underwent stereotactic biopsy and ventriculoperitoneal shunt placement. RESULTS: Pathologic diagnosis was juvenile pilocytic astrocytoma in both cases. The postoperative course of patient 1 was complicated by panhypopituitarism and failure of visual acuity to improve. He had disease progression after 2 cycles of monthly carboplatin, and was changed to TPCV chemotherapy per CCG-9952 protocol. There has been some radiographic response over 1 year and he continues on this regimen. Patient 2 has shown good radiographic response to vincristine/carboplatin per CCG-9952, without any shunt complications over 1 year. This patient has remained neurologically normal with intact vision and endocrine axis. CONCLUSIONS: The primary advantage to open surgical debulking may be in the potential for shunt independence in patients with associated hydrocephalus. Neurologic and endocrine function at presentation corresponded with posttreatment status in our patients. Chemotherapy alone can achieve good radiographic results, although long term outcomes are not known.