Angiolipoma

Angiolipomatosis is a group of tumors found mostly on the face, neck, chest and back. They are benign (noncancerous) growths made up of cells that produce the hormone angiotensin II (ATII). ATII is produced by many types of blood vessels throughout your body including those supplying your heart, brain, kidneys and other organs.

These tumors are not only common but also very dangerous. Most patients with these tumors die within two years after diagnosis. The prognosis for surviving beyond this time depends on several factors such as the size of the tumor, its location and how it affects your overall health.

The most common type of angiolipomatosis is called Angiolipomas of the Face or Angiolipoma of the Neck (AOFN). These tumors occur in approximately one out of every five men over age 40.

Other types include:

• Angiolipomas of the Chest (AAC): These tumors occur in approximately one out of every ten women over age 50.

• Angiolipomas of the Back (ABB): These tumors occur in approximately one out of twenty women under fifty.

The cause of angiolipomatosis is unknown. This condition tends to run in families and is more common among people with a history of blood vessel diseases (atherosclerosis, Buerger’s disease).

Angiolipomatosis starts when small blood vessels become damaged and then are gradually replaced by ATII-producing cells. The exact cause of damaged blood vessels is not known but it may occur as a result of injury. This condition has also been found to occur in the skin of patients with diabetes and in the retina of patients with retinopathy.

Most tumors begin as a small bump under the skin which grows slowly over months or years. As a tumor grows it may get bigger and become more firm. A doctor can usually feel a tumor, even though it may not be visible. A doctor may also be able to detect a tumor during an examination of the skin.

Tumors can occur anywhere there are blood vessels but they tend to grow in places where the skin is thinner such as the face, neck, armpits, and groin.

The most common symptom of angiolipomatosis is a painless bump or swelling under the skin. Other symptoms may include:

• Redness or blueness of the skin overlying the tumor

• Hard lumps under the skin

• Skin sores that do not heal

Complications of angiolipomatosis may include:

• Sticky or dry skin (xerosis) at the site of the tumor. This is a result of the increased blood flow to the area.

• Skin ulcers that do not heal

• Excessive hair growth (hirsutism)

• A darkened area of skin (hyperpigmentation). A result of increased blood flow to the affected area.

Tumors may become large enough to cause symptoms such as pain, swelling or problems with body functions (organs) that are close to the tumor. If this occurs, a doctor should be notified immediately.

Most angiolipomas are not cancerous (malignant). However, a biopsy is usually recommended to confirm the exact nature of the tumor. The diagnosis is made based on the appearance of the tumor during surgery. A pathologist examines a sample of the tumor under a microscope to determine the cell type.

A biopsy may also be done to rule out other problems that have similar symptoms such as:

1. Aneurysm – abnormal widening of an artery

2. Arteriovenous malformation – abnormal connection between an artery and vein

3. Thyroid tumor

4. Lipoma – a common lipid (fat) tumor

5. Angioma – a benign tumor made of blood vessels

6. Hidradenoma – a common skin tumor

7. Seborrheic keratosis – a common benign skin growth

8. Milia – small solid bumps filled with liquid

9. Molluscum contagiosum – a viral infection of the skin

Because most angiolipomas are not cancerous, treatment is based on the symptoms and specific manifestations of the condition. Most tumors do not cause symptoms and may be monitored without treatment.

If your dog has a skin lump or bump, make an appointment with your veterinarian. Angiolipomas are often found during a routine physical examination of the external body by a veterinarian.

Tumors located in areas that cannot be easily operated on may be treated with medication. If the tumor is causing skin irritation or problems with movement, surgery to remove the tumor may be performed. Occasionally, a small number of angiolipomas may regrow after treatment. Your veterinarian will monitor your dog following treatment.

If the tumor is cancerous, surgical removal may not be an option. Treatment may include chemotherapy and radiation therapy. Chemotherapy uses drugs to kill cancer cells. Radiation therapy uses high-energy rays to kill cancer cells. Radiation may be applied to the entire body (systemic radiation) or directed at the area of the tumor (localized radiation).

Combination chemotherapy uses both drugs and radiation therapy.

Your veterinarian will recommend a treatment plan following a biopsy of the tumor. Angiomas located in areas that cannot be easily accessed or safely removed may be monitored without further treatment.

Surgery to remove the tumor is often successful if:

1. The angioma is accessible and can be completely removed.

2. Cancer has not spread (metastasized) to distant organs.

3. There are no signs of angiomas in other parts of the body.

Tumors that do not cause problems for your dog may be monitored without treatment. Regression of the tumors may occur without any treatment at all.

1. Aorta – The largest artery in the body.

It starts at the left ventricle of the heart and extends to the body organs and limbs.

2. Arrhythmia – An irregular heartbeat.

3. Aneurysm – A localized, enlargement of a blood vessel, due to illness or injury.

4. Angina pectoris – Chest pain or discomfort due to muscle fatigue caused by not getting enough oxygen to the heart.

Pain may also be caused by the heart muscle weakness caused by a lack of blood flow.

5. Apoplexy – Sudden, severe brain injury caused by a disturbance in the normal blood flow in an artery supplying blood to the brain.

6. Arteries – Large, rigid blood vessels that carry blood away from the heart.

7. Atherosclerosis – The hardening or clogging of arteries with plaque due to low-density lipoprotein.

8. Cardiomyopathy – The disease of the heart muscle.

9. ECG – Abbreviation for electrocardiogram.

A record of electrical activity made by attaching small metal discs called electrodes to the skin and by passing an electric current through the body.

10. Echocardiogram – A medical imaging technique that makes a picture of the heart based on the echoes of sounds produced by the heart muscles.

11. Embolism – A substance that has traveled from one location to another within the body.

12. Endocarditis – Infection of the endocardium.

13. Euthanasia – Painless, gentle death of a person or animal. The most common ways are by intravenous injection of a drug (euthanizing) solution that causes rapid loss of consciousness and death, or by an overdose of anesthetic given to end the life of the patient.

14.

Sources & references used in this article:

Angiolipoma by WR Howard, EB HELWIG – Archives of Dermatology, 1960 – jamanetwork.com

Two entities in angiolipoma(A study of 459 cases of lipoma with review of literature on infiltrating angiolipoma) by JJ Lin, F Lin – Cancer, 1974 – Wiley Online Library

Infiltrating angiolipoma by F GONZALEZ-CRUSSI, WF ENNEKING, VM AREAN – JBJS, 1966 – journals.lww.com

Cellular angiolipoma. by SJ Hunt, DJC Santa, RJ Barr – The American journal of surgical …, 1990 – europepmc.org

Extradural spinal angiolipoma by FS Haddad, A Abla, CK Allam – Surgical neurology, 1986 – Elsevier

Intracranial angiolipoma. by PR Wilkins, C Hoddinott, MD Hourihan… – Journal of neurology …, 1987 – ncbi.nlm.nih.gov

Spinal angiolipoma by DR Fourney, KA Tong, RJB Macaulay… – Canadian journal of …, 2001 – cambridge.org