Tumors from Blood Vessles

Tumors from blood vessels can either consist entirely of the vessels themselves or grow from the vessel wall. A tumor, which is formed from many entangled blood vessels, arises from a marked proliferation of endothelial cells (eg hemangioma). In contrast, tumors originating from the vessel wall are of mesenchymal origin (eg fibroma, myxoma, fibrosarcoma). The two types are not necessarily mutually exclusive.

Vascular pseudotumors[edit | edit source]

Tumor-like formations include:

Telangiectasia - small dilated arteries near the epidermis (visible), eg spider nevus with characteristic short-term disappearance when pressed.
Pyogenic granuloma (lobular capillary hemangioma) - acquired, exophytically growing hyperplasia of blood vessels.

Benign vascular tumors[edit | edit source]

The most common benign tumor of this group is hemangioma. It occurs practically anywhere in the body, for example in the liver, where it can be mistaken for a metastasis.

Hemangioma: a collection of blood vessels containing erythrocytes, thus appearing red. They are common in different morphological variants.
- Capillary – a ball of blood vessels with a narrow lumen, they occur mainly in children.
- Cavernous – composed of dilated thin-walled vessels that look spongy under the microscope.
  - Naevus flammeus is a special form of cavernous hemangioma, due to its large size it forms "maps" (e.g. the characteristic sign of Mikhail Gorbachev).
'Glomangioma: a common, well-circumscribed benign tumor that is very painful. It is located in the area of arteriovenous anastomoses, often on the fingers or under the nail. It comes from modified smooth muscle cells found here.
Hemangioendothelioma': a solid tumor that can form capillaries with an overlying endothelium. It is common in youth and there are multiple variants with variable prognosis (malignant reversal is relatively common).
Hemangiopericytoma: originates from pericytes, contains reticular fibers demonstrable by Gomori's method. It is rare and occurs in the brain.

Malignant vascular tumors[edit | edit source]

Angiosarcoma': this is a malignant hemangioendothelioma. It is a rare, aggressive and highly malignant tumor.
Kaposi's sarcoma: develops in immunosuppressed individuals who have been infected with herpes virus 8. Characteristic are multiple foci on the skin and mucous membranes, sometimes in combination with leukemias and lymphomas.