Fig. 2

Clinical cases. Case 1 (sequence a-d) is shown in red and case 2 is shown in blue (sequence e-h). The MRIs were carried out during the clinical course of preliminary diagnosis (a and e) with liquid biopsy (c and g). Diagnosis was subsequently confirmed by conventional tissue biopsy (d and h). Finally, MRIs as part of the follow-up were respectively reported for the two cases (b and f). Case 1. In a pre-operative MRI of the head shows an expansive lesion with peritrigonal localization. The lesion dislocates the ventricular system with relative dilatation of the left temporal horn. The parenchymal side of the lesion, after contrast infusion, shows a strong enhancement in respect to the perilesional oedema. Para-sagittal and coronal sections after contrast perfusion show the lesion proximal to the IV cerebral ventricle. In b MRI, performed during the follow up, shows relapsing lesion. In c Liquid biopsy, H&E staining of short-time cultivated CTCs shows elements with gemistocytic pattern and moderate nuclear atypia. The black arrow shows a cluster of cells with eosinophilic cytoplasm. Scale bars: 100 μm. In d Tissue biopsy, H&E staining of histologic glioblastoma specimen. Please note the necrosis, the atypical astrocytic cell proliferation, and the gemistocytic features. Scale bars: 100 μm. Case 2. In e pre-operative MRI of the head shows acystic expansion entrapping the temporal horn of the left lateral ventricle with controlateral dislocation of the ventricular system. In f MRI, performed during the follow up after treatment shows left-sided cyst and dilated ventricle with reduction of contrast-enhanced MRI of the primary lesion. In g H&E staining of cytological elements on slides obtained by short-time expansion of CTCs. Please note large, round elements with abundant cytoplasm, indicated by four black arrows. Scale bars: 100 μm. In h H&E staining of excisional biopsy shows Diffuse Large B-Cell Lymphoma. Scale bars: 100 μm