Angiomas are benign tumours of either blood vessels(haemangiomas) or lymph vessels(lymphangiomas). The latter rarely occur, so angioma is usually taken to mean haemangioma.
Haemangiomas. These are not true tumours,but are sufficiently similar to be classified as such. They consist of an excessive growth of blood vessels,arranged in an uncharacteristic manner and interspersed with collagen fibres.
Capillary haemangiomas. Excess capillary growth interspersed with collagen in a localised area makes a dense,plexus-like network of tissue. Each haemangioma is supplied by only one blood vessel and if it thromboses,the haemangioma atrophies and disappears.
Cappilary haemangiomas are usually present at birth and are seen as a purple or red mole or birthmark. They may be quite small at birth but grow at an alarming rate in the first few months,keeping pace with the growth of the child.
Cavernous haemangiomas. Blood vessels larger than capillaries grow in excess normal needs in a localised area and are interspersed with collagen fibres. They are dark red in colour and may be present in the skin,though more commonly in the liver. They grow slowly,do not regress and may become large and unsightly.
