Diagnosis

Doctors use many tests to diagnose disease and determine its extent. Some tests may also determine which treatments may be the most effective. A biopsy is the only way to make a definitive diagnosis of mastocytosis. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out more about the disease. Your doctor may consider these factors when choosing a diagnostic test:

• Age and medical condition
• The type of disease suspected
• Severity of symptoms
• Previous test results

In addition to a physical examination, the following tests may be used to diagnose mastocytosis:

Laboratory tests. Tests on samples of the patient’s blood and urine may be able to detect high levels of mast cells and histamine, respectively. Blood tests can also determine how the liver, kidneys, and other vital organs are functioning. Tryptase (an enzyme) may be elevated in the case of systemic mastocytosis, which may help differentiate systemic mastocytosis from similar disorders.

Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that mastocytosis is present, but only a biopsy can make a definite diagnosis. The sample removed from the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). Skin biopsies are frequently used to diagnose mastocytosis.

Bone marrow aspiration and biopsy. A sampling of the bone marrow can be important in the diagnosis of systemic mastocytosis. The most common site to biopsy the bone marrow is the back of the pelvic (hip) bone. The skin is numbed and a needle is inserted into a bone in the hip until it reaches the marrow. A small amount of bone marrow is removed and examined under a microscope.

To learn about the terms used in this section, read the Cancer.Net Feature: Cancer Terms to Know: Newly Diagnosed.

To learn more about what to expect during common diagnostic tests, read Cancer.Net: Tests and Procedures.