A bone marrow biopsy is an essential part of the toolkit for the accurate diagnosis of systemic mastocytosis (SM). It is performed to analyze the mast cells, particularly their quantity, shape and position.
A clinician administers a local anesthetic then inserts a small needle into the hip bone to extract bone marrow fluid and a piece of bone marrow. The samples are sent to a laboratory for testing.
What is SM?
Systemic mastocytosis (SM) is a rare hematological disease characterized by mast cells that are overactive and accumulate in different parts of the body such as the bone marrow, liver, spleen, gastrointestinal tract and lymph nodes.
What is the significance of mast cells in SM?
SM is a mast cell disorder. Mast cells originate in the bone marrow and are then released into the blood. They then migrate to the skin and organ tissue, where they mature.
Read more about SM testing and diagnosis
The activation of mast cells is triggered by allergens, bacteria, viral products and foreign agents, causing the release of histamines, proteases, heparin and cytokines into the bloodstream.
In SM, the mast cells proliferate uncontrollably, leading to an excessive accumulation in the skin, tissue and organs.
Why is a bone marrow biopsy necessary?
In the diagnosis of SM, your doctor will take a full medical history and ask you about your symptoms. He or she may order a bone marrow biopsy, as well as blood or urine tests, a skin biopsy, imaging tests and genetic testing to ensure an accurate diagnosis.
A bone marrow biopsy will look at the shape of the neoplastic mast cells. In SM they occur in increased numbers and appear dense, compact and in a cluster. Their shape is spindled and elongated instead of isolated, round and granular. They can also form lesions — most often in indolent systemic mastocytosis.
What to expect
A bone marrow biopsy involves having a small needle inserted into the iliac crest, the curved part of the hip bone. It is a minimally invasive surgical procedure that is conducted with local anesthetic to reduce discomfort. You may feel a dull pressure on the bone, with pushing and pulling while the biopsy is extracted.
The procedure lasts around 30 minutes and is performed either by a hematologist or a specialized nurse. It has two steps: collecting the bone marrow aspirate sample — fluid containing hematopoietic cells, including red blood cells — and the core biopsy, which is a solid piece of bone marrow. Both samples are removed and sent to a laboratory to be analyzed under a microscope.
Following the procedure, you’re likely to experience some residual discomfort at the biopsy site. You may need to take pain relief in the first 24 hours and avoid physical exertion.
