Systemic mastocytosis (SM) can be associated with severe complications and can present with atypical symptoms, according to findings from a case study recently published in Annals of Medicine & Surgery.
Thus, researchers stated the development of a reliable diagnostic and therapeutic approach is of key import.
An urgent need exists to delve deeper into exploring the potential effects and manifestations of SM, in an effort to advance our understanding and improve the care of patients with the disorder, according to the study authors. Mastocytosis comprises a broad range of disorders that are exhibited by the clonal accumulation of mast cells in various tissues, organs, and body systems, including the skin, bone marrow, and gastrointestinal tract.
In mastocytosis, the accumulation of clonal mast cells is associated with gain-of-function mutations in the tyrosine kinase domain of the KIT gene. In adult patients with SM, the dominant mutation is KIT D816V.
Mastocytosis can be classified as cutaneous mastocytosis (CM), SM, or mast cell sarcoma (MCS). Sm can be further divided into the following subtypes:
- Indolent SM (ISM)
- Bone marrow mastocytosis
- Smoldering SM (SSM)
- ISM with an associated hematologic neoplasm (ISM-AHN)
- Aggressive SM (ASM)
- Mast cell leukemia (MCL)
Read more about SM treatment and care
In more than 90% of individuals with typical ISM, SSM, or ISM-AHN, “neoplastic mast cells carry the KIT D816V mutation.” The diagnosis of SM is rendered according to criteria established by the World Health Organization (WHO). To confirm an SM diagnosis, the presence of the major criterion and at least one minor criterion, or more than two minor criteria, is necessary, according to the WHO.
The major criterion involves multifocal, compact infiltrates of mast cells of greater than 15% in bone marrow biopsy and/or other extracutaneous organ. The minor criteria included the following:
- More than 25% of spindle-shaped mast cells in bone marrow smears
- Aberrant expression of CD25 and/or CD2 by bone marrow mononuclear cells
- Detection of KIT D816V mutation in bone marrow
- Serum tryptase levels greater than 20 ng/mL
The current case describes a 32-year-old male patient who presented with a “history of recurrent anaphylactic attacks and elevated serum tryptase levels without apparent skin involvement.” The patient was referred to a tertiary immunology department at Taleghani Hospital in Gorgan City, Iran. The diagnostic process involved and the clinical implications of noncutaneous mastocytosis are based on existing WHO criteria.
The case report presented the detailed medical history, clinical manifestations, and diagnostic of workup of the patient. Of note, the patient also had experienced three episodes of spontaneous loss of consciousness in the prior year, all of which were not associated with insect bites or with any other known trigger.
The patient’s detailed medical history discussed recurrent anaphylactic attacks that were triggered by a variety of factors, such as insect stings. His childhood history involved rhinitis, skin lesions and wheezing. The patient reported experiencing symptoms of flushing, coughing, severe dyspnea, abdominal pain and hypotension following insect stings. No remarkable findings were revealed on a comprehensive physical examination.
Laboratory tests demonstrated no significant abnormalities. Although oral food allergy tests were negative, his serum basal tryptase level was elevated at 28 ng/mL, which immediately raised suspicion of the presence of mastocytosis.
Bone marrow aspiration revealed a normocellular sample with an increased quantity of mast cells. Immunohistochemistry markers, especially CD117, were positive in scattered mast cells.
“Considering the patient’s recurrent anaphylaxis and the possibility of mastocytosis, an action plan was devised for anaphylaxis management and mastocytosis control was developed,” the study authors wrote.
The patient also provided his consent for the creation of a bee venom immunotherapy program.
“There is a pressing need to delve deeper into the investigation of the potential impacts and manifestations of mastocytosis to further our understanding and enhance patient care,” the authors concluded.
