Hemangioma

What is a hemangioma? 

A hemangioma is a non-cancerous tumour made from abnormal blood vessels. Without a microscope, the tumour looks red to blue in colour, and there tends to be a clear border between the tumour and the surrounding normal tissue.

This kind of tumour can start anywhere on the body, although they are most commonly found in the skin, head and neck, and liver. These tumours range in size from very small (1-2 millimetres) to very large (over 20 centimetres).

Hemangiomas can develop at any age. A tumour that is present at birth is called a congenital hemangioma. In contrast, a tumour that develops in the first few days or weeks after birth is called an infantile hemangioma. Other types of hemangiomas develop later in life.

Blood vessels

Blood vessels are hollow tubes that move blood around your body. Blood vessels that move blood away from the heart and towards the body are called arteries and arterioles. Blood vessels that bring blood back to the heart from the body are called veins or venules. The smallest blood vessels are called capillaries. They move blood inside an organ.

Types of hemangiomas

There are many different kinds of hemangiomas. The type of hemangioma depends on when the tumour developed, where the tumour is located on the body, and the types of blood vessels found inside the tumour. All types of hemangiomas are non-cancerous. Some types are likely to disappear on their own while other types may have to be removed surgically.

Common types of hemangiomas

• Capillary – This type is also called “strawberry hemangioma” because it has a red colour. It commonly starts in the skin and may slowly disappear over time.
• Cavernous – This type can be found in places like the liver, brain, and eye. Unlike other types of hemangiomas, it does not regress over time.
• Congenital – This type is present at birth.
• Epithelioid – This type is also called angiolymphoid hyperplasia with eosinophils is commonly found in the head and neck area. It can sometimes develop after an injury to the skin. When viewed under the microscope, lots of special immune cells called eosinophils are seen inside the tumour.
• Targetoid – This type is also called a hobnail hemangioma. It often has a bright red or blue centre with a pale or dark rim which looks like a ‘target’.
• Infantile – This type develops in the first few days or weeks after birth. It can regress over time.
• Lobular capillary hemangioma – Lobular capillary hemangiomas can grow very fast and can be initially confused for cancer. Some tumours develop after an injury and they are more common in women who are pregnant. This type is also called a pyogenic granuloma.
• Verrucous – This type develops shortly after birth and can look like a bump or ‘wart’ on the skin.
• Infiltrating – Most types of hemangiomas have a clear border between the tumour and the surrounding normal tissue. In contrast, the border of infiltrating hemangioma blends into the surrounding normal tissue which can make it difficult for your doctor to completely remove the tumour.

How do pathologists make this diagnosis?

The diagnosis of hemangioma can be made when a small sample of the tumour is removed in a procedure called a biopsy. The diagnosis can also be made when the entire tumour is removed and sent to a pathologist for examination under a microscope.

A hemangioma under the microscope

Tumour regression

Some types of hemangiomas can decrease in size or even disappear on their own over time. This type of change is called regression and it is more commonly seen in infantile hemangiomas.  Tumours that do not disappear on their own can be surgically removed. Some medications are also available to help shrink the tumour.

by Robyn Ndikumana MD BScN and Allison Osmond, MD FRCPC, updated December 14, 2020