Title:Diffuse Leptomeningeal Glioneuronal Tumors: A Case Series of Five Patients
with Parenchymal Forms and an Analysis of the Diagnostic Challenges,
Treatment Options and Outcomes
Volume: 19
Author(s): Mustafa Kemal Demir*, Ozlem Yapıcıer, Turker Kılıc, Serkan Celik, Bala Basak Oven, Umut Ozdamarlar, Naz Ece Kundak, Duaa Kanan, Alp Dincer, Onder Ertem, Tahsin Yakut, Baran Yılmaz and Sebnem Safi
Affiliation:
- Department of Radiology, Bahçeşehir University School of Medicine, Göztepe Medical Park Training and Education
Hospital, Istanbul, Turkey
Keywords:
Diffuse leptomeningeal glioneuronal tumor, glioneuronal tumor with oligodendroglioma-like cells, magnetic resonance imaging, histopathology, immunohistochemistry, CNS.
Abstract:
Background: Diffuse leptomeningeal glioneuronal tumors (DL-GNT) are rare glioneuronal
neoplasms with oligodendroglioma-like cells. These tumors can present as a dominant intracranial
mass or as a solitary spinal cord mass without leptomeningeal involvement. In this study, we aimed to
determine the magnetic resonance imaging and histopathological features, treatment modalities, and
clinical outcomes of the parenchymal forms of DL-GNTs.
Methods: This is a retrospective three-center case series study of 5 patients with a confirmed parenchymal
form of DLGTs, out of which 4 patients were adults. Brain and spinal cord MR imaging were
performed in all patients at either 1.5 or 3T. The patients' age ranged from 5 years to 50 years with a
mean age of 27.6 years at presentation.
Results: Four of the tumors were located in the frontal lobe, and one in the tectum. They were usually
solid-cystic enhancing tumors as the other mixed neuronal-glial tumors. All of the tumors had an extension
to the superficial surface of a cerebral hemisphere. One had systemic bone metastases. The
clinical signs and symptoms of the parenchymal form varied based on the location of the mass, in contrast
to the leptomeningeal form associated with hydrocephalus. In one case, the tumor’s initial grade
was defined as intermediate. The initial histopathology of the two cases was low-grade and no upgrade
occurred in the follow-up period. In two cases, although the tumors were low grade initially, they
progressed to an anaplastic form in the follow-up period.
Conclusion: The parenchymal form of DL-GNTs is common in adults. Extension to the superficial
surface of a cerebral hemisphere is a distinctive imaging feature. Systemic osseous metastasis may
occur. Due to the presence of common histopathological features, including the biphasic composition
of glial and neuronal cell elements and oligodendroglioma-like cells, a proposed classification approach
might be more beneficial for the histopathological and imaging description, and management of
the glioneuronal tumors with oligodendroglioma-like features.
