Clinical course of solitary extramedullary plasmacytoma.
OBJECTIVE
Solitary extramedullary plasmacytoma (EMP) represents a rare category of malignant disease on which there are limited data in regard to diagnosis, staging and natural history. This study attempted to clarify the clinical course of solitary extramedullary plasmacytoma after radiation or surgical therapy given with curative intent.


METHODS
The diagnosis was based on a mass of clonal plasma cells separate from bone or bone marrow without evidence of occult disease elsewhere. Between 1963 and 1996, 22 previously untreated patients with an EMP were diagnosed. Disease presented in the head or neck in 86%, usually in the nasal cavity (NC) or maxillary sinus (MS), and in these areas local bone destruction was found in 10 of 11 patients. Among all patients, serum myeloma protein was present in three patients (14%) and Bence Jones protein alone was found in two patients (9%). Radiation therapy was the sole treatment for 18 of 22 patients, and the median radiotherapy dose was 50 Gy (range, 40-60 Gy); five of seven patients with an EMP of oral cavity (OC), oropharynx (OP), nasopharynx (NP), parotid or larynx also received elective neck irradiation. Two patients underwent surgery plus postoperative irradiation of a plasmacytoma of the sigmoid colon or pleura, and two patients had resection alone of a plasmacytoma of the colon or cervical lymph node.


RESULTS
Local control was achieved in 21 of 22 patients (95%), and disease never recurred in regional nodes. Disappearance of myeloma protein occurred in three of five patients with an evaluable abnormality. Multiple myeloma developed in seven patients (32%), all within 5 years. The 5-year rate of freedom from progression to multiple myeloma was 56% and the median survival was 9.5 years.


CONCLUSIONS
Radiation therapy achieved excellent locoregional control of EMP with an approximate cure fraction of 50%.
Liebross
R H
RH
Department of Radiation Oncology, The University of Texas, M.D. Anderson Cancer Centre, Houston 77030, USA.
Ha
C S
CS
Cox
J D
JD
Weber
D
D
Delasalle
K
K
Alexanian
R
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001536:Bence Jones Protein / Q000032:analysis; D003110:Colonic Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018450:Disease Progression; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D015993:Life Tables; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000473:pathology; D009194:Myeloma Proteins / Q000032:analysis; D009367:Neoplasm Staging; D010950:Plasma Cells / Q000473:pathology; D010954:Plasmacytoma / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D010997:Pleural Neoplasms / Q000532:radiotherapy / Q000601:surgery; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D012074:Remission Induction; D012811:Sigmoid Neoplasms / Q000532:radiotherapy / Q000601:surgery; D015996:Survival Rate
D009194:Myeloma Proteins; D001536:Bence Jones Protein