Glioblastoma, IDH-wildtype manifesting as intracranial hemorrhage: A case report highlighting the clinical utility of digital polymerase chain reaction in integrated diagnoses

The manifestation of glioblastoma, IDH-wildtype (GB) as intracranial hemorrhage (ICH) presents diagnostic and therapeutic challenges. Molecular characteristics, including TERT promoter mutation, EGFR amplification, and chromosome 7 gain/10 loss, were incorporated to diagnose GB in the fifth edition of the World Health Organization Classification of Tumors of the Central Nervous System. When molecular analyses fail to detect low fractions of these genetic alterations, the integrated diagnosis of GB can be enigmatic. This case report describes a 58-year-old man presenting with ICH, masking an underlying GB. Initial histopathology of the evacuated hematoma revealed a small number of atypical glial cells, but a definitive diagnosis was deferred. Subsequent surgery and molecular analysis, including digital polymerase chain reaction (dPCR), confirmed the presence of a TERT C228T mutation in the promoter area, leading to an integrated diagnosis of GB. The patient experienced a favorable clinical outcome following surgery, radiation, temozolomide, and tumor-treating field therapy, without recurrence after 50 months. This case underscores the importance of meticulous histological examination of ICH and exemplifies the clinical utility of dPCR as a complementary diagnostic tool. The effectiveness of dPCR is particularly noteworthy, even in scenarios with minimal tumor cell content, reinforcing its value in the integrated diagnosis of GB.