Extraosseous plasmacytoma

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, and skin

Not Applicable
Module Rule
Module 2: PH2
Alternate Names
Extraosseous (extramedullary) plasmacytoma
Multiple extraosseous (extramedullary) plasmactyomas
Multiple plasmacytomas
Plasmacytoma, NOS (not occurring in bone)
Plasmacytoma refers to a malignant monoclonal plasma cell tumor growing within soft tissue.

Clonal proliferation of plasma cells cytologically and immunophenotypically identical to those of plasma cell myeloma but forming tumors at extraosseous and extramedullary sites.
Abstractor Notes
Do not code primary site to C40._ or C41._. These category codes should only be used with histology 9731/3.

These plasmacytomas are localized plasma cell neoplasms that arise in tissues other than bone. About 15% of upper respiratory plasmacytomas spread to the cervical lymph nodes.

Radiology and bone marrow examination show no evidence of involvement.

Do not code plasma cell myeloma/multiple myeloma (9732/3) just because there are multiple extraosseous plasmacytomas.

FISH and immunophenotyping help to differentiate these lesions from MALT lymphoma.
Definitive Diagnostic Methods
Genetic testing
Histologic confirmation
Genetics Data
Ig clonal rearrangements, complex karyotypes with multiple chromosomal gains/losses; also translocations, deletions, mutations
Small M protein, most commonly IgA
Transformations from
Same Primaries
There are no known 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)
Diagnostic Exams
Progression and Transformation
Regional recurrences occur in ~25% of patients
Occasionally metastasis to distant extraosseous sites
Progression 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