capillary hemangioblastoma

Etiology

• small number associated with von Hippel-Lindau disease

Epidemiology

• 7-10% of posterior fossa tumors
• 4% of spinal cord tumors

Pathology

• cerebellum most often involved (83%)
• also occurs in medulla (2%) & spinal cord (13%)
• occasionally multifocal
• often associated with or within a cyst & connected to meninges

Microscopic pathology

• reticular variant - uniformly distributed cells within intricate network of capillaries
• cellular variant - cells clustered forming groups separated by capillaries
• stromal cells
  • irregular hyperchromatic nuclei
  • eosinophilic, variably lipid rich, ill defined cytoplasm
  • abundant glycogen
  • mitoses absent or infrequent
• extramedullary erythropoiesis may be seen

Immunophenotype

• + vimentin,
• + neuron specific enolase
• +/- GFAP
• epithelial membrane antigen

Genetics

• inactivation of the vHL tumor suppressor gene
  • some sporadic cases
  • von Hippel-Lindau disease

Clinical manifestations

• may cause symptoms by compression of local neural structures
  • symptoms depend on location; i.e cerebellar ataxia, motor weakness, sensory deficits
  • pain may be a symptom
• bleeding may occur
• paraneoplastic syndrome may develop

Radiology

• magnetic resonance imaging (MRI) with gadolinium contrast
  • enhancing mass frequently associated with a cyst
  • smaller hemangiomas (< 10 mm) may be isointense on T1-weighted images & hyperintense on T2-weighted images
• angiography in conjunction with CT for patients who are not candidates for MRI

Complications

• compression of local neural structures
• spinal cord edema
• acute hemorrhage can be catastrophic

Differential diagnosis

• astrocytoma
• ganglioneuroma
• metastatic tumor

Management

• tumors best managed by multidisciplinary team including
  • neuroradiologist, radiation oncologist
  • neurosurgeon
  • neurooncologist
• preoperative angiogram
• embolization of feeding arteries may be indicated
  • microspheres, ethanol
• intra-operative microscopic microdissection
• stereotactic radiosurgery (gamma-knife radiosurgery)
• conventional radiation therapy
  • recurrence-free survival rates at 5,10 & 15 years are 76, 52 & 42%.

More general terms

• vascular tissue neoplasm; angioma
• central nervous system (CNS) neoplasm

Patient information

hemangioblastoma patient information