Gliomatosis cerebri

Abstract

A 21-year-old immunocompetent woman in apparent good health and without a significant past medical history presented with progressive headaches and horizontal diplopia. She was alert, oriented, and the remainder of the neurologic exam was unremarkable. Based on her brain MRI, what is the diagnosis?a)Acute viral encephalitisb)Multiple sclerosisc)Progressive multifocal leukoencephalopathyd)Gliomatosis cerebrie)Primary CNS lymphoma Stereotactic biopsy demonstrated WHO grade III astrocytoma, IDH mutant, ATRX lost. Her extensive involvement evidenced by imaging suggests a gliomatosis cerebri growth pattern. Gliomatosis cerebri refers to an extensive and invasive growth pattern that involves at least three contiguous lobes and typically resembles a low-grade lesion radiologically (e.g., non-contrast enhancing), but is associated with a poor prognosis [[1]Georgakis M.K. Spinos D. Pourtsidis A. Psyrri A. Panourias I.G. Sgouros S. et al.Incidence and survival of gliomatosis cerebri: a population-based cancer registration study.J Neurooncol. 2018; 138: 341-349Crossref PubMed Scopus (15) Google Scholar]. Until recently, it was classified separately within gliomas, but molecular studies did not warrant separation [[2]Cavenee W.K. Louis D.N. Ohgaki H. Wiestler O.D. International Agency for Research on Cancer. WHO classification of tumours of the central nervous system.Revised 4th ed. International Agency For Research On Cancer, Lyon2016Google Scholar]. It can be present in any diffuse glioma subtype, but it is especially common in anaplastic astrocytoma. Gliomatosis cerebri is generally categorized in two groups based on having a focal tumor mass: type 1 (no focal mass), and type 2 (with a focal mass). Treatment is challenging due to the extensiveness and irresectability of the lesion. Radiation therapy is especially restricted due to the extensive involvement, which often requires dosage adjusting, decreased length of therapy, and have a high likelihood of causing neurotoxicities [[3]Morales La Madrid A. Ranjan S. Warren K.E. Gliomatosis cerebri: a consensus summary report from the Second International Gliomatosis cerebri Group Meeting, June 22–23, 2017, Bethesda, USA.J Neuro-oncol. 2018; Crossref Scopus (9) Google Scholar]. Lower doses of ionizing radiation may also reduce the effectiveness of chemotherapy, as the length of concurrent radiation can be reduced. Our patient being younger, received a full dose of radiation (59.4 Gy) with concurrent temozolomide for 6 weeks, followed by maintenance temozolomide for one year. She tolerated treatment well, but unfortunately progressed soon afterwards and passed away after initiating bevacizumab. Gliomatosis cerebri remains a therapeutic challenge that warrants further investigation (Fig. 1). Dr. Garcia: Concept, design, drafting, revising, and critical revision of content. Dr. Villano: Concept, design, drafting, revising, and critical revision of content. The authors have no disclosures.