Hemangioblastoma

Hemangioblastoma occur almost exclusively in the posterior fossa, with almost 20% occurring in patients with von Hippel-Lindau disease. Other tumors associated with von Hippel-Lindau are renal cell carcinoma, pheochromocytoma, and retinal angiomas. Many will look as a cystic tumor within enhancing tumor on the cyst wall known as a mural nodule. The entity itself is benign.

Epidemiology
Most often seen in patients between 15 and 50 years old with no effect of race on incidence. There appears to be a dominant inheritance pattern of von Hippel-Lindau disease.

Clinical Manifestations
Hemangioblastoma of the cerebellum: most often seen with von Hippel-Lindau disease. Symptoms include dizziness, ataxia, headache, symptoms and signs of increased intracranial pressure from fourth ventricle compression. Later sequelae include development of malignant renal or adrenal tumors. Patients will also have polycythemia due to erythropoietin factor release by the tumor.

Hemangioblastoma is of the spinal cord: frequently associated with syringomyelic lesions.

Retinal hemangioblastoma: may lead to blindness if not treated by laser

Differential Diagnosis

 * Pilocytic astrocytoma: much more common in children, while hemangioblastoma would be more common in adults.
 * Metastasis: most common cerebellar adult neoplasm
 * Toxoplasmosis
 * Cystic gliomas

Diagnostic Tests
Based on capillary hemangioblastoma is of the central nervous system or retina in the presence of one von Hippel-Lindau associated tumor or a previous family history.

Treatment
Surgical resection is curative.

Radiology
A CT or MRI of a cerebellar cyst will show and enhancing nodular lesion on the wall. The associated retinal hemangioma will also be shown. The angiography will be diagnostic with a tight cluster of small vessels forming a mass. Multiple central nervous system hemangioblastoma is our characteristic. The lesions may be heterogeneous or homogenous to include cystic components, solid components or combined. Specific characteristics include a highly vascular, enhancing mural nodule associated with a predominantly cystic mass in the lateral cerebellum.

In patients with von Hippel-Lindau disease the hemangiomas will be multiple.

Look for large blood vessels leading to the nodule.

Pathology
Will reveal many thin-walled vascular channels.

Is intra-axial.

Gross specimen will show a cyst within enhancing mural module.

Microscopic examination: highly vascular, lipid stromal cells