Glioblastoma diagnosis
Diagnostic tools for glioblastoma diagnosis include computed tomography (CT or CAT scan) and magnetic resonance imaging (MRI).
Even though the appearance of the usual Glioblastoma is widely recognizable, one must bear in mind the possibility of unusual presentation. A case highlights the diagnostic difficulties of diffuse glioblastoma with atypical clinical presentation 1).
Magnetic resonance imaging
Positron emission tomography
Positron emission tomography (PET scan) can help detect recurring brain tumors.
Thirty-five percent of patients with a radiological diagnosis of glioblastoma in the western region of Sweden region lacked histological diagnosis. Apart from high age and poor performance status, they had more severe comorbidities and extensive tumor spread. Even for this poor prognostic group upfront treatment with temozolomide was shown of benefit in a subgroup of patients. This data illustrate the need of non-invasive diagnostic methods to guide optimal individualized therapy for patients considered too fragile for neurosurgical biopsy 2).
Histopathology
They are comprised of a heterogeneous population of tumor cells, immune cells, and extracellular matrix.
Interactions among these different cell types and pro-/anti-inflammatory cytokines may promote tumor development and progression.
Histologically, they are characterized by hypercellularity, nuclear pleomorphism, microvascular proliferation, and pseudopalisading necrosis.
Glioblastomas are among the most vascularized tumors in humans. There is also an abnormal vascular remodeling process that leads to microvascular proliferation that is a histopathological hallmark of glioblastoma.
In these tumors, angiogenesis appears to be triggered by expression of vascular endothelial growth factor, an important regulator of tumor blood vessel permeability 3).