MRI features of canine hemangiosarcoma affecting the central nervous system

Abstract

Hemangiosarcoma is the most common metastatic tumor involving the brain in dogs but detailed published descriptions of the magnetic resonance imaging (MRI) features are lacking. The objective of this multi‐center, retrospective case series study was to describe MRI characteristics of canine hemangiosarcoma affecting the central nervous system (CNS). Medical records of seven referral institutions were retrospectively reviewed. Dogs were included if they had a histopathologically confirmed diagnosis of hemangiosarcoma affecting the CNS and undergone an MRI of the brain and/or vertebral column. Lesions were independently evaluated by two observers. Twenty dogs met the inclusion criteria and one dog had both intracranial and intramedullary hemangiosarcoma. Consistent MRI features included heterogeneous (17/21) lesions in all sequences with mainly mixed signal intensity (12/21), presence of susceptibility artifact on T2*w (15/16), associated moderate to severe perilesional edema (21/21), and moderate to strong (20/21) heterogeneous (14/21) or ring‐like (6/21) contrast enhancement. Intracranial hemangiosarcoma was frequently multiple and intra‐axial, affecting consistently the telencephalon and no differences in MRI features were found between primary and metastatic hemangiosarcoma. This is the first MRI description of primary intracranial hemangiosarcoma and primary intracranial epithelioid hemangiosarcoma. Vertebral hemangiosarcomas were segmental poorly marginated polyostotic and highly aggressive lesions invading the thoracic vertebral canal and paraspinal tissues. Epidural hemangiosarcomas were single and well‐marginated lesions in the thoracolumbar and/or lumbar region. Intramedullary hemangiosarcomas were cervical, metastatic in origin, and frequently (3/4) accompanied by intracranial lesions. These described MRI features will aid early identification of hemangiosarcoma guiding subsequent diagnostics and therapeutics.

Cranial and vertebral osteosarcoma commonly has T2 signal heterogeneity, contrast enhancement, and osteolysis on MRI: A case series of 35 dogs

“…12 Spinal hemangiosarcoma has been reported to arise from the vertebrae or within the vertebral canal. 12,23,24 In one report, vertebral hemangiosarcoma had similar signal intensity and contrast enhancement compared to the cases of osteosarcoma reported here. Interestingly, three of four cases were polyostotic, and only one case had T2*weighted images available.…”

“…22 Future studies are warranted Magnetic resonance imaging features of undifferentiated sarcoma and hemangiosarcoma have been described. 12,13,23,24 Both osteosarcoma and undifferentiated sarcoma typically cause cortical lysis, but undifferentiated sarcoma is often centered on the paraspinal soft tissues. 12 Spinal hemangiosarcoma has been reported to arise from the vertebrae or within the vertebral canal.…”

“…Interestingly, three of four cases were polyostotic, and only one case had T2*weighted images available. 24 Susceptibility artifacts in T2*-weighted images may be a distinguishing feature of hemangiosarcoma; how-ever, the prevalence of this finding in dogs with osteosarcoma is not known, as many MRI protocols do not routinely include T2*-weighted images. 24,25 Magnetic resonance imaging features of chondrosarcomas have been described.…”

“…24 Susceptibility artifacts in T2*-weighted images may be a distinguishing feature of hemangiosarcoma; how-ever, the prevalence of this finding in dogs with osteosarcoma is not known, as many MRI protocols do not routinely include T2*-weighted images. 24,25 Magnetic resonance imaging features of chondrosarcomas have been described. 12,26 In one report of six dogs, the osteolytic and osteoproliferative masses involved the dorsal compartment of multiple consecutive vertebrae.…”

Clinical, Diagnostic, and Imaging Findings in Three Juvenile Dogs With Paraspinal Hyperesthesia or Myelopathy as a Consequence of Hemophilia A: A Case Report

“…Magnetic resonance imaging characteristics of hemorrhage into the vertebral canal have been reported previously in several case studies (5)(6)(7)(8)(9). Vertebral canal hemorrhage may be secondary to coagulopathy, neoplasia, trauma, intervertebral disc herniation, acute non-compressive nucleus pulposus extrusion, inflammatory diseases, iatrogenic, traumatic, or may be idiopathic (5,(7)(8)(9)(10)(11)(12)(13)(14). The progression of hemoglobin degradation and therefore the imaging findings may proceed differently than in the brain due to variability in the local environment, but this has not been established in the dog (5,15,16).…”