PMC10157200_01
Brain magnetic resonance imaging (MRI) and histopathological imaging. (A) Left-to-right, each row includes T2- and T1-weighted images (w.i.) and histological features at precise time points. First row, Time 0 (onset): a large intra-axial hemorrhagic (T1 spontaneous hyperintensity) lesion surrounded by edema (T2 hyperintensity) is visible in the right frontal-parietal region. View of Masson Trichrome stain (original magnification x20) showing partially organized hematoma surrounded by granulation tissue. Second row, Time 3 months: three small, new intracranial hemorrhagic lesions with extensive edema are noted. The left frontal lesion, shown in the figure, was removed and underwent a histopathological examination, which is concluded as a hemangioendothelioma (HE); in particular, the tissue morphology was characterized by papillary structures covered by a single endothelial cell layer, expressing the endothelial-specific markers, as CD31 (x20). Third row, Time 4: a new left frontal hemorrhagic mass is documented; histology with Masson Trichrome (x20) revealed the fibrous wall of hematoma and an area consisting of vascular proliferation with papillary architecture compatible with HE. Fourth row, Time 20: a new right hemispheric cerebellar hemorrhagic lesion associated with mass effect is found. Low-magnification (x10) view of the hematoxylin and eosin stain of the lesion shows only a partially organized hematoma. Fifth row, Time 80: the figure shows a new large hemorrhagic mass in the left parasagittal frontal region surrounded by edema. Hematoxylin and eosin stain (x20) demonstrate a compact network of papillary structures with a collagenous axis, suggestive of intravascular papillary endothelial hyperplasia (IPEH, Masson's tumor). (B) Times 87 (left) and 89 (right): T2* w.i. (top row) show that three further lesions with hemosiderin deposition (T2* hypointensities) without recent-bleed hyperintensity in T1 w.i. (bottom row) in right internal subcapsular (Time 87) and frontal and parietal white matter (Time 89), respectively. Note: arrows show the new lesions on MRI images. (C) T2 w.i. (top) and contrast-enhanced T1 w.i. (bottom) at Time 116, after 27 months of treatment with sirolimus, showing no new lesions.
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Brain magnetic resonance imaging (MRI) performed 4 days after clinical onset showed a right frontal-parietal hemorrhagic lesion (Figure 1A). The left basal frontal nodule (Figure 1A) was excised, and the headache resolved. After 4 months of the initial visit (Time 4), the patient presented with acute-onset right arm palsy; a brain MRI revealed a new lesion in the left motor cortex (Figure 1A). MRI revealed a right hemispheric cerebellar mass with radiological features similar to that of the previous lesions (Figure 1A). Brain MRI revealed a large hemorrhagic left frontal lesion (Figure 1A). In two brain MRIs, obtained at the 87th month (Time 87) and 89th month (Time 89) from the onset, new hemosiderin alterations in the right internal subcapsular (Figure 1B, left) and frontal and parietal white matter (Figure 1B, right) showed that three further lesions had occurred, without clinical signs. The last follow-up was performed 43 months into the treatment, and at the 132nd month from the onset (Time 132, Figure 1C).
The treatment timeline of the patient. Single-line units in the last 12 months. Dotted squared space: systemic therapy [interferon (IFN), red; sirolimus, green].
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