Figure 1.

MRI images of the patient's brain tumour. Panel 1. Fluid Attenuated Inversion Recovery (FLAIR) images show the IDH1-mutant GBM at diagnosis in August 2014 (A–D) and ~8 months later, at the last follow-up MRI examination (December 2016) prior to surgical excision of the enhancing nodule (E–H). The lesion discovered on August 2018 is centered in the right inferior frontal lobe (A,B, arrowheads), and abuts the premotor cortex (C, arrowhead). There is an enhancing nodule within the lesion, as seen in the magnified post-contrast image (D) (arrow). This enhancing lesion measured 1.25 mL, which is calculated using the V = ABC/2 formula. Follow-up MRI (E–H) demonstrates interval progression of the non-enhancing tumor (arrowheads). Interval increase in size of the enhancing lesion, measuring 5.97 mL, was also observed (H, arrow). Panel 2 shows the evolution of the lesion between the May 2017 surgical excision (A–C), and in the most recent MRI evaluation, dated March 2020 (D–F). T2-weighted images indicate the residual GBM (arrowheads). (B) shows the T2-hyperintense GBM filling the surgical cavity. The lesion in the premotor cortex is clearly seen in (C). Please note that the surgical debulking involved only the enhancing tumor, while the largest non-enhancing part of the GBM was not excised by the neurosurgeon. The most recent brain MRI (D–F) shows interval increase in size of the GBM (arrowheads), which remains circumscribed to the right frontal region without infiltrating the white matter tracts.