Diagnosis of Hemangioma
Hemangiomas can be confused with other vascular malformations. Because treatment may vary considerably depending on whether the lesion is a hemangioma or other type of malformation, a thorough doctor's examination is recommended.

Medical History and Physical Examination
Before a physical examination, your doctor will talk with you about your general health and current condition-or that of your child's, if you are a parent or family member. He or she will want to get a good history of the lesion, particularly how long the mass has been there and whether it has changed at all over time. Your doctor will want to know what symptoms-such as pain-are associated with the lesion, and when the symptoms began.

During the physical examination, your doctor will inspect and palpate any mass, noting exactly where it is located, what it feels like, and perhaps any surrounding changes in the skin.

Tests
Although doctors can often diagnose hemangiomas based on medical history and physical examination alone, imaging tests can be helpful.

X-rays and computerized tomography (CT) scans. Although these tests create better pictures of dense structures like bone, plain x-rays and CT scans may show a cavernous hemangioma if it has calcifications. These calcifications are called phleboliths.

Magnetic resonance imaging (MRI) scans. These scans can create clear images of soft structures like a hemangioma. Hemangiomas in an MRI scan are often described as a "bag of worms" due to the way the blood vessels pack around one another.

Angiogram. In this test, dye is injected into the surrounding blood stream making the hemangioma show up in an x-ray image.

Biopsy. At times, it may be difficult to distinguish hemangiomas from other tumors, and a biopsy is sometimes necessary to confirm a diagnosis of hemangioma. In a biopsy, a tissue sample of the tumor is taken and examined under a microscope. Looking at the tissue under a microscope may be the best way to tell if the tumor is indeed a hemangioma and what subtype it is.

During the biopsy, your doctor may give you a local anesthetic to numb the area and take a sample using a needle. Biopsies can also be performed as a small operation.

Blood tests. If there are multiple tumors or if your symptoms are concerning for a specific disease pattern, your doctor may recommend blood tests for genetic analysis.