Significance of perilesional T1 hyperintense areas in the differential diagnosis of primary adult-type diffuse glioma: A case report

Abstract

Perilesional T1 hyperintensity on magnetic resonance imaging (MRI) of intra-axial brain masses is an unusual feature of the perilesional area, characteristic of cavernous malformations (CMs) and metastatic brain tumors (METs). Here, we report a case of primary diffuse glioma with a perilesional T1 hyperintense area (HIA) on MRI. A 61-year-old woman with transient aphasia visited our hospital. Radiological examination revealed an intra-axial mass with acute/subacute hemorrhaging and calcification in the left frontal lobe. It was presumed to be a CM because of the perilesional T1 HIA. Gross total resection of the tumor was performed, and the pathological diagnosis was anaplastic oligodendroglioma, not otherwise specified by World Health Organization 2016 classification. Histopathological findings in the perilesional T1 HIA indicated hemorrhage involvement in the surrounding white matter. No recurrence appeared after radio-chemotherapy. Perilesional T1 HIAs, characteristic of CMs and METs, are also seen in primary diffuse gliomas. Therefore, caution should be taken when using this sign for the differential diagnosis of intracranial masses.

Keywords: Cavernous malformation; Glioma; MRI; Oligodendroglioma; Perilesional T1 hyperintense area.

Fig. 1

Computed tomography (A, B) showing an intra-axial mass with partial hemorrhage and calcification in the left frontal lobe. Partially include a slightly high-density area suspected intratumoral hemorrhage.

Fig. 2

T1-weighted images (WIs) (A) showing a perilesional high-intensity area (HIA), which also indicates high intensity on T2WIs (B). T2*WIs (C) suggest hemosiderin deposition and a hemorrhage in the lesion. The lesion rim shows ring-like contrast enhancement by gadolinium (D). MRI Axial T1WIs show regions of interest located in the perilesional T1 HIA (1) and the contralateral white matter (2). The mean T1 signal intensity ratio of the perilesional area to the contralateral white matter is 1.26 (E).

Fig. 3

Histopathological findings of the tumor (A) show cells with round nuclei and perinuclear haloes. Microvascular proliferation (arrow) and necrosis (arrowhead) are also seen in this field which suggests the high-grade malignancy of this tumor (Hematoxylin and Eosin staining, x100). In the perilesional white matter (B), brown and yellow hemosiderin (arrow) are scattered in the tissue (Hematoxylin and Eosin staining, x200).