From the Guidelines
Yes, mastocytosis can be detected on a bone marrow biopsy, which is actually one of the key diagnostic procedures for systemic mastocytosis. During a bone marrow biopsy, pathologists look for characteristic clusters or aggregates of mast cells, typically consisting of 15 or more cells, as stated in the guidelines by the National Comprehensive Cancer Network 1. These abnormal mast cells often have a spindle-shaped appearance and may show atypical morphology. Special stains like tryptase, CD117 (c-KIT), and CD25 are used to identify these mast cells, as CD25 expression is particularly important since it's not typically found on normal mast cells 1. The bone marrow examination can also reveal other features of mastocytosis such as fibrosis, increased eosinophils, or abnormalities in other cell lines. For a definitive diagnosis of systemic mastocytosis, the bone marrow findings are combined with other criteria including serum tryptase levels, KIT D816V mutation testing, and clinical symptoms 1. In some patients with cutaneous mastocytosis only, the bone marrow may be normal, but for systemic forms, bone marrow involvement is a defining characteristic.
Some key points to consider in the diagnosis of mastocytosis include:
- The presence of multifocal, dense infiltrates of mast cells (≥15 mast cells in aggregates) in the biopsy sections of bone marrow and/or other extracutaneous organs, which is a major diagnostic criterion for systemic mastocytosis 1.
- The use of special stains and immunohistochemistry markers, such as tryptase, CD117, and CD25, to identify mast cells and determine their morphology and immunophenotype 1.
- The importance of evaluating the bone marrow for features of mastocytosis, including the percentage of neoplastic mast cells, their morphology, and the presence of associated hematologic neoplasms or other abnormalities 1.
- The need to consider other causes of mast cell activation symptoms, such as secondary mast cell activation syndrome or hereditary alpha-tryptasemia, in patients with suspected mastocytosis 1.
Overall, the diagnosis of mastocytosis requires a comprehensive approach that includes clinical evaluation, laboratory testing, and bone marrow examination, as outlined in the guidelines by the National Comprehensive Cancer Network 1.
From the Research
Mastocytosis Diagnosis
Mastocytosis can be noted on a bone marrow biopsy, as it is a key diagnostic tool for systemic mastocytosis. The diagnosis of systemic mastocytosis is substantially based on the histologic examination of bone-marrow biopsy specimens 2.
Bone Marrow Involvement
The bone marrow tryptase level appears to be a valuable diagnostic criterion for confirming systemic mastocytosis 3. A cut-off value of 50 μg/L for bone marrow tryptase identified systemic mastocytosis with a sensitivity of 93.0% and a specificity of 90.0% 3.
Diagnostic Criteria
Mastocytosis is a morphologic diagnosis and should not be diagnosed on the basis of clinical findings alone 4. The use of antibodies against tryptase, CD117 (KIT), and CD25 is recommended in every suspected case 4.
Key Findings
- Mastocytosis can be diagnosed by examining bone marrow biopsy specimens 2, 4, 5.
- Bone marrow tryptase level is a valuable diagnostic criterion for systemic mastocytosis 3.
- Serum tryptase levels can reflect the burden of neoplastic mast cells and are used as a diagnostic marker in mastocytosis 6.
- The updated classification for mast cell disease clarifies the clinical and pathological criteria for categorizing patients into relatively discrete subgroups 5.
Diagnostic Approaches
Some key diagnostic approaches for mastocytosis include: