Diffuse Midline Glioma with H3-K27M Mutation: A Rare Case with GFAP-positive Anucleate Whorled Patterns

Abstract

Background: Diffuse midline glioma with H3-K27M mutation is a new tumor type in the 2016 WHO classification of tumors of the central nervous system, with predominantly astrocytic differentiation and is characterized by K27M mutation in either H3F3A/-HIST1H3B/C. It occurs at the midline of the CNS. It is mainly found in children, and adult cases are relatively rare . Although its histopathological features have been widely described, GFAP-positive anucleate whorled patterns have not been reported to the best of our knowledge. Hence, we have reported this unusual case.Case presentation：A woman presented with complaints of walking instability. MRI showed a mass shadow of isometric T1 and slightly longer T2 with mild mixed signals in the third ventricle of the suprasellar region, about 3.4 x 2.5 x 3.4 cm in size. The enhanced scan showed that the lesion was irregular and annular, with a clear edge. The lesion had spread to the right lateral ventricle, which dilated the ventricular system, especially the right lateral ventricle. Furthermore, the lamellar long T2 signal was seen in bilateral paraventricular white matter, the midline structure had shifted to the left, and the corpus callosum was thinner. Radiological findings suggested ependymoma. Subtotal resection craniotomy was performed. After surgery, the patient was routinely treated with temozolomide for chemotherapy and synchronous radiotherapy (Dt=60 Gy/30f). It has been 11 months now, and the patient is living well.Result: We described an extremely rare case of diffuse midline glioma, H3-K27M mutation with GFAP-positive anucleate whorled patterns. Conclusions: This case report provides information on the microscopic morphological features of diffuse midline glioma with H3K27M mutation, which can help pathologists to make a definitive diagnosis of this tumor.

Exosomes Derived from Hypoxic Glioma Cells Reduce the Sensitivity of Glioma Cells to Temozolomide Through Carrying miR-106a-5p

“… 3 , 4 TMZ often promotes apoptosis by inducing the DNA damage. 5 , 6 The prognosis of many patients is not ideal as the glioma cells could acquire chemoresistance. 7 , 8 It has been revealed that low oxygen tension (hypoxia) established in growing tumor masses could induce the chemoresistance of tumor cells.…”