Hemangioblastoma

The hemangioblastoma is an extremely rich vascular tumor, which can also occur in the soft tissue in the region of the central nervous system.

Hemangioblastomas are typically associated with the von Hippel -Lindau syndrome (VHL ), but may also occur sporadically. Hemangioblastomas of the central nervous system are classified as benign tumors according to the WHO classification of tumors of the central nervous system as a grade I.

Localization

Hemangioblastomas are frequently localized in the cerebellum, brainstem or spinal cord, are rare but also supratentorial ago. In the area of ​​the retina of the eye occurring hemangioblastomas are often incorrectly referred to as retinal angiomas.

Symptoms

Depending on the location of the tumor may cerebellar symptoms (eg impaired locomotor coordination (ataxia) or speech (dysarthria ) ), a spinal spinal cord injury or nerve root compression syndrome occur. Since some hemangioblastomas are the growth factor erythropoietin, a secondary production of red blood cells ( polycythemia ) occur.

Diagnostics

In radiological imaging, provide hemangioblastomas as contrast -accomodating, often pseudocystic room exposures;

Pathology

Histologically, it is a highly vascularized tumor. When frequent reticular subtype can be seen between densely packed capillary blood vessels located in the tumor stroma individual larger cells with pale or clear, often vacuolated cytoplasm, referred to as stromal cells, their histogenesis remains unclear. Rare is the already described by Harvey Williams Cushing and Percival Bailey cellular subtype, in which the stromal cells are summarized in cell bales, and reminds its histological appearance to that of paragangliomas. In the differential diagnosis important distinction from metastasis of renal cell carcinoma (which also occur frequently in patients with von Hippel -Lindau syndrome) may immunohistochemically in particular the lack of staining of the stromal cells for the epithelial membrane antigen ( EMA) and evidence of low proliferative activity in the staining for Ki67/MIB-1 be helpful.

Treatment and prognosis

Treatment is by surgical removal of the tumor. After complete removal of the tumor, the prognosis is generally favorable. Relapses occur in about 10 % of patients and seem particularly to affect the cellular subtype of Hämangioblastoms. The distinction from a newly developed second malignancies may be difficult in patients with von Hippel- Lindau disease.