Abstract

Glioblastoma is the most common primary brain tumour in humans. Diagnostic challenges can occur as glioblastomas are highly heterogeneous tumours. The aim of this study was to investigate the frequencies and correlations between several histological features in primary glioblastomas and describe any link to tumour biology.

Two hundred consecutively diagnosed adult patients with primary glioblastoma located supratentorally were included after revision according to the 2007 World Health Organization criteria. Several histological features were examined. All tumours contained necrosis and/or microvascular proliferation, with frequencies of 98.5% (197/200) and 84.5% (169/200) respectively. Most tumours had detectable mitoses (192/200, 96%), with a median value of 8.5 per 10 high power fields. Further, pseudopalisades (158/200, 79%), thromboses (157/200, 78.5%), atypical mitoses (119/200, 59.5%), and haemorrhages (106/200, 53%) were other common features. Among relevant correlations necroses were positively associated with pseudopalisades, thromboses, small cells and mitoses.

In conclusion, glioblastomas present a variety of cell types and histological features, important to know and be aware of for the diagnostic pathologist. Interestingly, microvascular proliferation and necroses were frequently found in co-existence. Further, several of these features are closely linked to tumour biology, making histopathology fundamental for increased understanding of gliomagenesis.

Keywords: Glioma; Astrocytoma; Brain tumour; Classification; Morphology; Diagnosis