In a new study published in Case Reports in Hematology, researchers report on a rare case of acute myeloid leukemia (AML) relapse five years after an allogeneic stem cell transplant to treat systemic mastocytosis (SM) with associated hematological neoplasm (SM-AHN).
SM-AHN is a subtype of SM where SM occurs alongside another blood disorder — in this case, AML. AML is an aggressive type of blood cancer that affects the bone marrow and blood. For some individuals living with the disease, an allogeneic stem cell transplant offers the best chance of long-term remission or cure. Most relapses occur within the first year after transplant.
In this case, a 41-year-old woman with SM and AML achieved remission of both diseases after being treated with chemotherapy and a stem cell transplant. Five years later the leukemia returned. However, signs of SM did not: a bone marrow biopsyBone marrow biopsy A procedure to collect a sample of bone marrow using a needle. Often used to examine the characteristics of mast cells and diagnose SM. did not find unusual mast cells, and her serum tryptaseTryptase A protein enzyme that is primarily produced by mast cells and stored in small pockets within the cells, known as granules. High levels of tryptase are a key indicator of SM. levels were within the expected range.
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The long period before AML relapse and the fact that SM did not recur are both rare, the authors noted.
“The long duration of remission before relapsing in this case is exceptional, suggesting that the patient experienced a prolonged period of immune surveillance and control,” they wrote. The authors noted such a late relapse illustrates the need for long-term follow-up in individuals who undergo stem cell transplantation for leukemia.
Additionally, the report adds to evidence that blood cancers can evolve in unexpected ways years after apparent remission. The authors call for more research into the connections between mast cellMast cell A type of white blood cell produced in the bone marrow. They help defend against infections and play a key role in allergic reactions. In SM, mast cells become overactive and build up throughout the body. disorders and leukemia, which could ultimately lead to more personalized treatment strategies.
“Further research and patient characteristics are needed to better understand the rare disease entity of AML with SM and to optimize and improve treatment outcomes for this patient cohort,” the researchers concluded.
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