Histologically benign, clinically aggressive: Progressive non‐optic pathway pilocytic astrocytomas in adults with NF1. Issue 6 (14th March 2016) - Strowd, Roy E.
Abstract : Although optic pathway gliomas are the most common brain tumors associated with neurofibromatosis type 1 (NF1), extra‐optic gliomas occur and may behave more aggressively with outcomes that differ by age. A retrospective case‐control study was designed to describe the clinical course of adult NF1 patients with progressive extra‐optic pilocytic astrocytomas (PAs) and compare to a pediatric cohort. Data for patients treated at the Johns Hopkins Comprehensive Neurofibromatosis Center from 2003 to 2013 were reviewed to identify cases (adults, age >18) and controls (pediatric, age <18) with clinically or radiographically progressive extra‐optic PAs. Demographic, clinical, histologic, and radiographic data were collected. Three adult NF1 cases and four pediatric NF1 controls were identified. Mean age was 32.3 ± 9.5 years, 66% male (cases); 12.8 ± 4.2 years, 100% male (controls). Symptomatic progression occurred in two‐of‐three adults (67%) while the majority of pediatric patients presented with isolated radiographic progression (n = 3, 75%). Onset tended to be more rapid in adults (4 ± 1 vs. 14 ± 8.3 months, P = 0.10). Subtotal resection was the treatment for all pediatric patients. Radiotherapy (n = 2), chemotherapy (n = 2), and targeted, biologic agents (n = 2) were administered in adults. Although all pediatric patients are living, outcomes were universally poor in adults with progression to death in all (median survival 17.1 months, range 6.6–30.3). In conclusion, despite grade I histology, all three adult NF1 patients with progressive extra‐optic PAs suffered an aggressive clinical course which was not seen in pediatric patients. Clinicians should be aware of this clinico‐histologic discrepancy when counseling and managing adult NF1 patients with progressive extra‐optic PAs. © 2016 Wiley Periodicals, Inc.