Tectal glioma as a distinct diagnostic entity: a comprehensive clinical, imaging, histologic and molecular analysis

Abstract

Tectal glioma (TG) is a rare low-grade tumor occurring predominantly in the pediatric population. There has been no detailed analysis of molecular alterations in TG. Risk factors associated with inferior outcome and long-term sequelae of TG have not been well-documented. We retrospectively studied TGs treated or referred for review at St. Jude Children’s Research Hospital (SJCRH) between 1986 and 2013. Longitudinal clinical data were summarized, imaging and pathology specimen centrally reviewed, and tumor material analyzed with targeted molecular testing and genome-wide DNA methylation profiling. Forty-five patients with TG were included. Twenty-six (57.8%) were male. Median age at diagnosis was 9.9 years (range, 0.01–20.5). Median follow-up was 7.6 years (range, 0.5–17.0). The most common presenting symptoms were related to increased intracranial pressure. Of the 22 patients treated at SJCRH, 19 (86%) required cerebrospinal fluid diversion and seven (32%) underwent tumor-directed surgery. Five patients (23%) received radiation therapy and four (18%) systemic therapy. Ten-year overall and progression-free survival were 83.9 ± 10.4% and 48.7 ± 14.2%, respectively. Long-term morbidities included chronic headaches, visual symptoms and neurocognitive impairment. Lesion ≥3cm2, contrast enhancement and cystic changes at presentation were risk factors for progression. Among those with tumor tissue available, 83% showed growth patterns similar to pilocytic astrocytoma and 17% aligned best with diffuse astrocytoma. BRAF duplication (a marker of KIAA1549-BRAF fusion) and BRAF V600E mutation were detected in 25% and 7.7%, respectively. No case had histone H3 K27M mutation. DNA methylation profile of TG was distinct from other brain tumors. In summary, TG is an indolent, chronic disease with unique clinical and molecular profiles and associated with long term morbidities. Large size, contrast enhancement and cystic changes are risk factors for progression.Electronic supplementary materialThe online version of this article (10.1186/s40478-018-0602-5) contains supplementary material, which is available to authorized users.

Clinical, imaging, and molecular analysis of pediatric pontine tumors lacking characteristic imaging features of DIPG

“…Analysis of genome-wide DNA methylation profiles was performed as previously described [17][18][19][20]. Reference methylation profiles of IDH-mutant astrocytomas and H3 K27M-mutant DMG of the diencephalon and spinal cord were downloaded from a publicly available database for comparison [21].…”

Surgical Management and Prognostic Factors Based on 50 Tectal Plate Gliomas

“…The benefit of a pathological diagnosis is that it can identify the characteristics and grade of the tumor and guide subsequent treatment. [2,19]The follow-up treatment of patients with TG is very important based on the pathological diagnosis. [5,21] In our group of patients, one patient underwent ETV and received a biopsy.…”

“…Tectal glioma (TG) represents a unique subset of typically low-grade gliomas arising in the tectal region at the roof of the brainstem. [1,2] The clinical presentation is often related to symptoms of obstructive hydrocephalus from the compression of the cerebral aqueduct, including headache and nausea typically attributed to increased intracranial pressure. [3][4][5] Endoscopic third ventriculostomy (ETV) is a neurosurgical approach used to redirect cerebrospinal flow and is currently the most often used approach for the treatment of obstructive hydrocephalus.…”

Freiburg Neuropathology Case Conference:

“…A subgroup of brainstem gliomas, tectal glioma are rare low-grade tumors predominantly manifesting in children and young adults complaining about headaches caused by aqueduct stenosis and should be considered as differential of pineal region masses in rare cases when tectal gliomas are larger sized, invasive and not clearly nascent from the tectal plate [ 10 ]. MRI typically demonstrates a nonenhancing, T1-hypointense and T2-hyperintense lesion with “T2 shine through” phenomenon on DWI.…”

“…Due to their relatively benign course, CSF diversion is very often the only necessary treatment for symptom relief. In the rare cases of progress, contrast enhancement and cystic lesions are encountered [ 10 – 12 ]. In our case the clear enhancement made this diagnosis less likely.…”