A 55-year-old man with a type of blood cancer called acute myeloid leukemia was found to have mast cell leukemia after cancer treatment, according to a recent case report published in the journal Clinical Cytometry.
Mast cell leukemia is the most advanced form of systemic mastocytosis (SM). It is often linked to changes in certain genes, including TET2, SRSF2, ASXL1 and RUNX1.
The patient went to the doctor with easy bruising. Blood tests showed too many white blood cells and too few platelets, which are cells that stop bleeding. Bone marrow tests found that 40% of his blood-making cells were “blasts,” immature blood cells — a hallmark of leukemia. Doctors also noticed a higher-than-normal number of mast cells mixed in with the leukemia cells.
What is a mast cell?
Mast cells are specialized cells of the immune system that mediate inflammatory responses and allergic reactions. They are found in the body’s connective tissue.
Special genetic tests found several gene mutations but no changes in a gene called KIT, which is commonly seen in SM. Because the patient’s test results did not match the typical pattern for SM, doctors diagnosed the patient with acute myeloid leukemia with mast cell differentiation.
The patient received strong chemotherapy. The leukemia cells mostly went away, but the mast cells increased in number, filling over 75% of the bone marrow. Further testing confirmed the mast cells had transformed into another cancer: mast cell leukemia.
Read more about SM testing and diagnosis
Notably, a highly sensitive test called digital droplet PCR later found a small amount of the KIT mutation that standard testing had missed entirely. This suggests that routine genetic tests may sometimes fail to catch mast cell disease.
Despite trying several different treatments, the mast cell leukemia did not respond well. The patient entered hospice care and eventually passed away.
“Management remains challenging and underscores the need for novel targeted therapeutic approaches,” the case report authors said.
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