case_images: PMC10927221_01
case_images: Baseline noncontrast computed tomography and magnetic resonance imaging (MRI) images of the brain. (a) Coronal view shows an interhemispheric mass with left-sided mass effect. (b) Axial view using bone window reveals lytic involvement of calvarium. (c) Axial T2-weighted MRI shows superior sagittal sinus involvement. (d) Coronal T2-weighted MRI reveals tumor extension through the calvarium. (e) Sagittal T1-weighted MRI post-gadolinium shows tumor enhancement.
case_images: SNI-15-55-g001.jpg
case_images: PMC10927221_01_SNI-15-55-g001.jpg
case_images: F1
case_images: A baseline head computed tomography (CT) scan showed a lobulated hyperdense soft-tissue mass along the interhemispheric fissure and superior sagittal sinus (SSS) [Figures 1a and b]. Magnetic resonance imaging (MRI) of the brain with and without gadolinium demonstrated a large, hemorrhagic, and multilobulated enhancing mass measuring 10.3 x 4.8 x 4 cm (anteroposterior x transverse x craniocaudal dimensions) along the interhemispheric fissure encasing the SSS with possible sinus occlusion [Figures 1c and d]. There was biparietal calvarium involvement, including the inner and outer tables extending into the subgaleal soft tissues [Figure 1e].
case_images: Histologic features of the intracranial composite hemangioendothelioma. (a) Hematoxylin and eosin (H&E)-stained section shows an area of epithelioid hemangioendothelioma, with cells containing intracytoplasmic vacuoles embedded in a hyaline stromal matrix. (b) H&E-stained section shows an area of retiform hemangioendothelioma, with abundant arborizing vascular channels. (c) H&E-stained section shows an area of hemangioma, with dilated vascular channels lined by oval nuclei without atypia. (d) An anti-CD31 antibody reveals abundant endothelial cells in this neoplasm. (e) An anti-ERG antibody confirms the abundant endothelial cells in this neoplasm. (f) The Ki-67 proliferation index is low, with up to 3.6% of cells labeled with this antibody.
case_images: SNI-15-55-g002.jpg
case_images: PMC10927221_01_SNI-15-55-g002.jpg
case_images: F2
case_images: Approximately 30% of the neoplasm had abundant eosinophilic cytoplasm, nuclear atypia, and intracytoplasmic vacuoles with occasional hyalinized stroma, consistent with EHE [Figure 2a]. Many areas of the neoplasm (approximately 50%) consisted of long, branching, and thin-walled blood vessels with monomorphic cells that protruded into the lumen, occasionally forming a hobnail pattern consistent with RHE [Figure 2b]. In focal areas (approximately 20% of the examined neoplasm), markedly dilated thin-walled vascular channels were lined by bland, oval nuclei [Figure 2c]. Many of the tumor cells were strongly positive for CD31 [Figure 2d] and ERG [Figure 2e] by immunohistochemistry. The Ki-67 proliferation index was variably mildly elevated [Figure 2f].