Search Database ICD-O-3 Code Lists

Name

Mast cell sarcoma (MSC)

ICD-O-3 Morphology

9740/3: Mast cell sarcoma
Effective 2001 and later

Reportable

for cases diagnosed 1978 and later

Primary Site(s)

See Module 7
Most common sites of involvement: bones, gastrointestinal tract, lymph nodes, skin.
Spleen commonly involved (but this is not primary site), along with common metastatic sites liver and bone marrow.

Coding Manual: Hematopoietic Coding Manual (PDF)

Abstractor Notes

Mast cell sarcoma is part of the Mastocytosis lineage table in the WHO 5th edition of Hematolymphoid Tumors. (See Appendix B in the Hematopoietic Manual, Table B3)

Any organ or system may be involved, although the bones and gastrointestinal tract are most often affected, followed by the lymph nodes, skin spleen, liver

If the Mast cell sarcoma (9740/3) and mast cell leukemia occur during the same clinical workup, this is one primary, the mast cell leukemia.

If the Mast cell sarcoma occurs after the diagnosis of the mast cell leukemia, that is a manifestation of the mast cell leukemia and is the same primary.

See Multiple Primary Rule M3

Diagnostic Confirmation

This histology can be determined by positive histology (including peripheral blood) with or without genetics and/or immunophenotyping. Review the Definitive Diagnostic Methods, Immunophenotyping and Genetics Data sections below, and the instructions in the Hematopoietic Manual for further guidance on assigning Diagnostic confirmation.

Module Rule

None

Alternate Names

Definition

Mast cell sarcoma (MCS) is a rare and clinically aggressive form of mastocytosis characterized by the presence of a locally destructive solid tumor comprising highly atypical mast cells. (WHO 5th edition)

MCS usually shows locally obstructive growth and progression to aggressive systemic mastocytosis (9741/3) or mast cell leukemia (9742/3) (See abstractor notes regarding mast cell leukemia).

Definitive Diagnostic Methods

Histologic confirmation
Immunohistochemistry
Immunophenotyping

Genetics Data

None

Immunophenotyping

Immunohistochemical markers anti-tryptase/chymase and anti-CD117
KIT (CD117)+ (expression/positive)

Treatments

Chemotherapy
Radiation therapy
Surgery

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)

C96.22 Mast cell sarcoma (effective October 01, 2015)
C96.20 Malignant mast cell neoplasm, unspecified (effective October 01, 2015)

Signs and Symptoms

Abdominal pain
Arthralgias
Bone pain
Dermatographism
Diaphoresis
Fatigue
Fever
Flushing
Fractures
Gastrointestinal distress
Headache
Hepatosplenomegaly
Hypotension
Myalgias
Neutropenia
Osteopenia/osteoporosis
Pruritis
Respiratory problems
Syncope
Tachycardia
Thrombocytopenia
Urticaria
Weight loss

Diagnostic Exams

Bone marrow aspiration and biopsy
CT (CAT) Scan
Cytogenetics analysis
Flow cytometry
Immunophenotyping
Lumbar puncture
Molecular analysis
Peripheral blood smear
Physical exam and history
Skeletal survey
Skin biopsy

Progression and Transformation

Mast cell sarcoma is initially localized, followed within months by distant spread and terminal phase.

Epidemiology and Mortality

Survival: aggressive course, death within 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: 71-72

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