Search Database ICD-O-3 Code Lists

Name

Malignant mastocytosis (ICD-O-4: 97410/3)

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.

Diagnostic Confirmation

Assign code 1 for histological confirmation WITH or WITHOUT positive immunophenotyping or genetics

Module Rule

None

Alternate Names

Systemic mastocytosis with AHNMD (ICD-O-4: 97415/3)
Systemic mastocytosis with an associated hematological neoplasm (SM-AHN) (ICD-O-4: 97415/3)
Systemic mastocytosis with associated clonal hematological non-mast cell lineage disease (AHNMD) (ICD-O-4: 97415/3)
Systemic mastocytosis with associated clonal hematological non-mast cell lineage disorder (AHNMD) (ICD-O-4: 97415/3)

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.

Definitive Diagnostic Methods

Cytogenetics
Genetic testing
Histologic confirmation
Immunohistochemistry
Immunophenotyping

Genetics Data

KIT mutations (primarily p.D816V)

Immunophenotyping

CD2, CD25, CD30, CD117, mast cell tryptase

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
Pruritis
Respiratory problems
Syncope
Tachycardia
Thrombocytopenia
Urticaria
Weight loss

Diagnostic Exams

Bone marrow aspiration and biopsy
CT (CAT) scan
Cytogenetic analysis
Flow cytometry
Immunophenotyping
Peripheral blood smear
Physical exam and history
Skeletal survey
Skin biopsy

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

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
Glossary