Background
Systematic review and meta-analysis of extramedullary plasmacytoma (EMP), combining published series with the authors' own institutional data. 400+ cases analyzed. EMP arises outside bone marrow, most commonly in the upper aerodigestive tract (~80%: nasopharynx, nasal cavity, oropharynx, larynx, paranasal sinuses). Also occurs in GI tract, skin, thyroid, and other soft tissues.
Interventions and follow up
Arm A: RT alone (most common approach)
Arm B: Surgery ± RT; or combined modality; retrospective pooled analysi
Primary endpoint: Local control, overall survival, progression to multiple myeloma
mFollow up: Variable across included serie
Arm B: Surgery ± RT; or combined modality; retrospective pooled analysi
Primary endpoint: Local control, overall survival, progression to multiple myeloma
mFollow up: Variable across included serie
Results
Local Control (RT ± surgery): ~80–90%
5-Year OS: ~67%
Progression to Multiple Myeloma: 11–15% (substantially lower than bone SP)
Head/neck EMP: Best outcomes; >80% LC with RT ± surgery
GI tract EMP: Higher risk of local recurrence; resection often required
5-Year OS: ~67%
Progression to Multiple Myeloma: 11–15% (substantially lower than bone SP)
Head/neck EMP: Best outcomes; >80% LC with RT ± surgery
GI tract EMP: Higher risk of local recurrence; resection often required
Adverse events
Main adverse events: RT toxicity dependent on site: mucositis and xerostomia for head/neck EMP treated with RT. Surgery carries site-specific risks. Combined modality increases morbidity.
Conclusions
EMP is radiosensitive and has a favorable prognosis compared to bone SP, with low rates of progression to MM (~11–15%). RT alone achieves excellent local control for head/neck EMP. Surgery is preferred for resectable GI tract lesions, with RT for positive margins or unresectable disease.
Key Limitations
Key Limitations: Pooled retrospective analysis spanning decades with heterogeneous patient populations, RT techniques, and staging criteria; publication bias toward institutional series with good outcomes; no standardized RT doses across series; modern imaging (PET/CT) not used in older series.
Clinical Context
Classic reference establishing EMP as a distinct, favorable entity vs. bone SP. The ~11% MM progression rate vs. ~50% for bone SP drives different surveillance intensity and counseling. RT doses of 40–50 Gy are standard for EMP per ILROG 2018 guidelines, consistent with this review's findings.
References