Simultaneous Supratentorial and Infratentorial Pilocytic Astrocytomas in an Adult Patient with Concurrent Neurofibromatosis Type 1 and HIV Infection.

Neurofibromatosis type 1 (NF1) has been identified as a predisposing factor in the development of pilocytic astrocytoma (PA), a common benign central nervous system tumor. Although this is a common association, simultaneous development of multiple lesions is an infrequent finding, especially in nonoptic and hypothalamic locations. A 41-year-old female patient with NF1 and uncontrolled human immunodeficiency virus (HIV) type 1 infection presented with a first generalized seizure and associated headache and ataxia. Imaging studies revealed 2 large intra-axial PAs, nodular-cystic in the supratentorial compartment and solid in the infratentorial compartment. Both lesions were treated by gross total resection in 2 surgeries performed 1 week apart. Despite their different imaging patterns, the tumors were histologically and genetically identical. We present a unique case involving 2 histologically and genetically identical PAs occurring simultaneously in supratentorial and infratentorial locations. We suggest that an intrinsic predisposition to tumor development in patients with NF1 might have been enhanced by the HIV-related immunosuppression in this case. Strict oncologic surveillance is essential in patients with a tumor predisposition syndrome combined with immunosuppression.