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Name
ICD-O-3 Morphology
9741/3: Malignant mastocytosis
Effective
2001 and later
Reportable
for cases diagnosed
1978 and later
Primary Site(s)
C421
Primary site must be bone marrow (C421)
Coding Manual:
Hematopoietic Coding Manual (PDF)
Abstractor Notes
Systemic mastocytosis with an associated hematological neoplasm (SM-AHN) is part of the Mastocytosis lineage table in the WHO 5th edition of Hematolymphoid Tumors. (See Appendix B in the Hematopoietic Manual, Table B3)
See 9741/1 if the diagnosis is systemic mastocytosis, NOS, indolent systemic mastocytosis, bone marrow mastocytosis, or smoldering systemic mastocytosis
If the diagnosis "systemic mastocytosis with an associated hematological neoplasm (SM-AHN)" occurs at the same time as another hematological neoplasm (For example, SM-AHN with CMML found on bone marrow biopsy), this is the same primary and the histology is 9741/3.
If the CMML is diagnosed first, followed later by the SM-AHN, then the SM-AHN is a second primary.
See 9741/1 if the diagnosis is systemic mastocytosis, NOS, indolent systemic mastocytosis, bone marrow mastocytosis, or smoldering systemic mastocytosis
If the diagnosis "systemic mastocytosis with an associated hematological neoplasm (SM-AHN)" occurs at the same time as another hematological neoplasm (For example, SM-AHN with CMML found on bone marrow biopsy), this is the same primary and the histology is 9741/3.
If the CMML is diagnosed first, followed later by the SM-AHN, then the SM-AHN is a second primary.
Diagnostic Confirmation
None
Module Rule
None
Alternate Names
Malignant mastocytosis
Systemic mastocytosis with AHNMD
Definition
Systemic mastocytosis (SM) is a myeloid neoplasm characterized by clonal proliferation of mast cells, typically harbouring mutant KIT, involving at least one extracutaneous organ system, with or without evidence of skin lesions. (WHO 5th edition)
Systemic mastocytosis with an associated hematological neoplasm (AHN): This fulfills the general criteria for systemic mastocytosis as well as the criteria for an AHN. In most cases, a myeloid disease of non-mast cell lineage is detected, such as a myelodysplastic syndrome, myeloproliferative neoplasm, myelodysplastic/myeloproliferative neoplasm or acute leukemia.
Aggressive systemic mastocytosis (ASM): Mast cells in bone marrow smears may be increased in number, but account for less than 20% of all nucleated bone marrow cells. Most patients with ASM have no skin lesions.
Systemic mastocytosis with an associated hematological neoplasm (AHN): This fulfills the general criteria for systemic mastocytosis as well as the criteria for an AHN. In most cases, a myeloid disease of non-mast cell lineage is detected, such as a myelodysplastic syndrome, myeloproliferative neoplasm, myelodysplastic/myeloproliferative neoplasm or acute leukemia.
Aggressive systemic mastocytosis (ASM): Mast cells in bone marrow smears may be increased in number, but account for less than 20% of all nucleated bone marrow cells. Most patients with ASM have no skin lesions.
Definitive Diagnostic Methods
Cytogenetics
Genetic testing
Histologic confirmation
Immunophenotyping
None
Treatments
Chemotherapy
Immunotherapy
Transformations to
There are no known transformations
Transformations from
There are no known transformations
Same Primaries
Corresponding ICD-10 Codes (Cause of Death codes only)
C96.2 Malignant mast cell tumor
Corresponding ICD-10-CM Codes (U.S. only)
C96.21 Aggressive systemic mastocytosis (effective October 01, 2015)
Signs and Symptoms
Abdominal pain
Anemia
Arthralgias
Bone pain
Dermatographism
Diaphoresis
Eosinophilia
Fatigue
Fever
Flushing
Fractures
Gastrointestinal distress
Headache
Hepatosplenomegaly
Hypotension
Leukocytosis
Myalgias
Neutropenia
Osteopenia/osteoporosis
Organ impairment
Pruritis
Respiratory problems
Syncope
Tachycardia
Thrombocytopenia
Urticaria
Weight loss
Diagnostic Exams
Progression and Transformation
None
Epidemiology and Mortality
Age: primary second decade of life
Sex: no male or female predominance
Survival: patients with cutaneous involvement only follow indolent course and may have a normal life expectancy. Patients with no skin lesions and aggressive disease may survive only a few months
Sources
WHO Classification of Tumours Editorial Board. Haematolymphoid tumours. Lyon (France): International Agency for Research on Cancer; 2024. (WHO classification of tumours series, 5th ed.; vol. 11). https://publications.iarc.who.int/637.
Section: Mastocytosis
Pages: Part A: 64-70
Section: Mastocytosis
Pages: Part A: 64-70
International Classification of Diseases for Oncology, 3rd edition (including revisions). Geneva: World Health Organization, 2001, 2011, 2020.
Section: ICD-O-3.2 (2020) Morphological Codes
Pages: http://www.iacr.com.fr/index.php?option=com_content&view=category&layout=blog&id=100&Itemid=577
Section: ICD-O-3.2 (2020) Morphological Codes
Pages: http://www.iacr.com.fr/index.php?option=com_content&view=category&layout=blog&id=100&Itemid=577
