10 questions about vascular neoplasms of the skin: what is important to know
Vascular neoplasms of the skin are multifaceted, mysterious, and sometimes poorly predictable. They can be the first signs of both a malignant tumor and a systemic or infectious disease. Let's try to understand this issue and find answers to frequently asked questions.
What vessels form the microcirculatory bed of the skin?
The microcirculatory bed includes vessels with a diameter of less than 100 microns. These vessels can be divided into resistive capillaries, sphincters, capillaries, resistive postcapillaries and shunt vessels according to their main functions. The microcirculatory bed itself is the section of the vascular bed where the blood performs almost all of its metabolic functions. Significant thickening of the skin vessels is observed near the sensory organs, around the natural openings of the face and in the skin of the pads of the fingers. Vascular neoplasms and diseases can affect all sections of the microcirculatory bed.
How does the blood supply to the epidermis and dermis occur?
There are no blood vessels in the epidermis, and there are two parallel vascular plexuses in the dermis - superficial and deep. These vascular plexuses consist of arterioles, venules and capillaries and are interconnected by perpendicularly arranged vessels. The accepted division into two vascular plexuses is rather conditional and is used mainly for the diagnosis and description of inflammatory skin diseases. Multiple capillary loops extend from the superficial plexus, located in the reticular layer of the dermis, to the papillary layer. There are from 40 to 70 such loops per square millimeter of skin. Each loop of the so-called capillary “candelabra” has an ascending arterial part and a descending venous part. It is they who nourish the epidermis. Capillaries are true exchange vessels, other vessels create the conditions necessary for exchange.
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