ICD-O-1 Morphology

9731/3: Solitary plasmactyoma of bone
Effective 1978 - 1991

ICD-O-2 Morphology

9731/3: Solitary plasmactyoma of bone
Effective 1992 - 2000

ICD-O-3 Morphology

Effective 2001 and later


for cases diagnosed 1978 and later

Primary Site(s)

See Module 7
Primary site cannot be bone (C400-419). Most common sites of involvement: upper respiratory tract (80%), oropharynx, nasopharynx, sinuses, larynx, gastrointestinal tract, lymph nodes, bladder, CNS, breast, thyroid, testis, parotid gland, and skin


Not Applicable

Module Rule

Module 2: PH2

Alternate Names

Extraosseous (extramedullary) plasmacytoma
Plasmacytoma, NOS (occurring outside of bone)
Solitary plasmacytoma (occurring outside of bone)


Solitary plasmacytomas are single localized tumors consisting of monoclonal plasma cells with no clinical features of plasma cell myeloma (PCM)(see 9732/3) and no physical or radiological evidence of additional plasma cell tumors.

Extraosseous (extramedullary) plasmacytomas are localized plasma cell neoplasms that arise in tissues other than bone. They occur most commonly in the mucous membranes of the upper air passages, but they can also occur in numerous other sites, including the gastrointestinal tract, lymph nodes, bladder, breasts, thyroid, testes, parotid glands, skin and CNS.

Plasmacytomas of the upper respiratory tract spread to cervical lymph nodes in about 15% of cases.

Abstractor Notes

This is a localized solitary tumor in sites other than the bone consisting of monoclonal plasma cells. Complete skeletal radiographs (preferably MRI) show no other lesions. If additional lesions are found on MRI or CT (or other radiological surveys), this is diagnostic of plasma cell myeloma (see 9732/3).

Do not code primary site to C40._ or C41._. These category codes should only be used with histology 9731/3.

FISH and immunophenotyping help to differentiate these lesions from MALT and Marginal zone lymphomas.

Definitive Diagnostic Methods

Genetic testing
Histologic confirmation

Genetics Data

t(11;14)(q13;q32) (IGH.CCNDI) lacking


C19 positive
CD20 expressed
CD45 positive
CD56 weakly positive
Cyclin DI (usually lacking)


Radiation therapy

Transformations to

Transformations from


Same Primaries

Corresponding ICD-9 Codes

203.8 Other immunoproliferative neoplasms

Corresponding ICD-10 Codes

C90.2 Plasmacytoma, extramedullary

Corresponding ICD-10-CM Codes (U.S. only)

C90.2 Extramedullary plasmacytoma (effective October 01, 2015)

Signs and Symptoms

Presence of M-protein, most commonly IgA (~20% of patients)

Progression and Transformation

Regional recurrences occur in ~25% of patients
Occasionally metastasis to distant extraosseous sites
Transformation to plasma cell myeloma occurs in ~15% of cases

Epidemiology and Mortality

Age: 55 years median age
Sex: male predominance
Survival: ~70% of patients remain disease free at 10 years


Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J (Eds):
WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (Revised 4th edition)
IARC: Lyon 2017
Section: Mature B-cell neoplasms
Pages: 251-253

International Classification of Diseases for Oncology, Third Edition, First Revision. Geneva: World Health Organization, 2013.
Section: ICD-O-3.1 (2011) Morphological Codes
Pages: http://codes.iarc.fr/codegroup/2

National Cancer Institute
Section: General Information About Plasma Cell Neoplasms
Pages: https://www.cancer.gov/types/myeloma/hp/myeloma-treatment-pdq