In order to effectively grasp the oddity that the radiographic image of this patient presents, the differences between CCMs and GBMs on MRI must be accurately delineated. CCMs or cavernomas are vascular abnormalities of the brain that are primarily composed of a collection of irregular, hyalinized capillaries circumscribed within a gliotic margin showing hemosiderin deposits. [10] Co-existence and even mimicry of such lesions have been previously reported in literature, albeit, rarely. [4][11] Generally, CCMs can be differentiated from gliomas by the absence of mass effect and peripheral edema, however, these features are observed in the presence of hemorrhage, [12] as was the case for our patient.
On a genetic basis, it is well documented in literature that IDH-1 mutations are frequently observed in what was previously defined as ‘secondary’ GBM (73–85%) [6][13], which develop from a preexisting lower-grade glioma; a disease state that is in line with the diagnosis of the case we present. However, these mutations are rarely if ever present in ‘primary’ GBM [13], with the converse, the relationship of wild-type with GBM origin status, holding true as well. Further, IDH-1 mutations have been linked to younger age of patients who concomitantly suffer from either astrocytoma, anaplastic astrocytoma, anaplastic oligoastrocytoma, or glioblastoma [14]. Lastly, it has also been observed that patients with lower-grade gliomas tend to suffer from epilepsy as opposed to those with higher-grade gliomas [9].
Thus it is clear that the case we present is unique in relation to currently published literature on the subject, as not only did our patient’s GBM present as a mimetic CCM, her 20-year long history of epilepsy (which, according to the epidemiological data above, puts her below the mean age) points to her affliction being a lower grade glioma primarily, which then progressed into a glioblastoma; however, the molecular profile of the patient signifies the development of a de novo glioblastoma, due to the absence of an IDH-1 mutation. Similarly, a consistent association of increased serum GFAP concentration has been seen in relation to the development of IDH-1 wild-type GBM, [15] a factor additionally present in the molecular profile of the patient we present.