Plasmacytoma is a discrete, solitary mass of plasma cells growing in either bone or soft tissue. Solitary plasmacytoma can be present as a single bony lesion (medul lary) or in soft tissue outside the bone (extramedullary). Plasmacytoma also is referred to as:

• plasma cell dyscrasia

• plasma cell myeloma

• malignant plasmacytoma

• plasmacytoma of bone

• plasma cell tumor

• plasmacytoma of the skeletal system

• solitary bone plasmacytoma

• soft tissue plasmacytoma

• extramedullary plasmacytoma.

Plasmacytoma can arise in any part of the body. Solitary plasmacytoma of the bone is more common and arises from the plasma cells located in the bone marrow. Soft tissue plasmacytoma is thought to arise from plasma cells located in mucosal surfaces. The most common site for solitary plasmacytoma of the bone is the axial skeleton, specifically the spine. The most common site for soft tissue plasmacytoma is the upper respiratory tract.

No definite cause has been found for solitary plasmacytoma of the bone. The etiology of soft tissue plasmacytoma in the upper respiratory tract is probably related to chronic stimulation of inhaled irritants or viral infection. However, several risk factors have been noted to increase the risk for plasmacytoma. These include radiation exposure, heredity and carcinogens.

The signs and symptoms of plasmacytoma depend upon the location of the tumor, and whether the tumor is in bone or in soft tissues. Solitary plasmacytoma of the bone is typically asymptomatic. When symptoms occur, the most common symptom is pain in the local area, or a pathologic fracture from weakening of that area of bone. There can be compression of nerve roots in the spine from a growing tumor. Compression fractures of the thoracic and lumbar vertebral bodies usually result in severe spasms and back pain.

In soft tissue plasmacytoma, the most common symptom is a fleshy swelling that continues to enlarge over several months. Soft tissue plasmacytoma presenting as a mass growing in the upper respiratory tract (that spreads to lymph nodes) usually has the following signs on clinical examination:

• swelling

• headache

• nasal discharge

• epistaxis

• nasal obstruction

• sore throat

• hoarseness

• dysphonia

• dysphagia

• dyspnea

• epigastric pain

• hemoptysis

Tests include x-rays, computed tomography (CT) scan, magnetic resonance imaging (MRI) of the bone, chemistry profile, biopsy, urinalysis and complete blood count (CBC).

Treatment includes surgery and localized radiation therapy.

The prognosis depends on where the plasmacytoma is located. Solitary plasmacytoma of the bone compared to soft tissue plasmacytoma is more likely to progress to multiple myeloma (see Diagnostic Code: 7712 Multiple myeloma) which is characterized by the excessive growth and malfunction of plasma cells in the bone marrow. The growth of these extra plasma cells interferes with the production of red blood cells, white blood cells, and platelets. Solitary plasmacytoma of the bone progresses to multiple myeloma at a rate of 65-84% at 10 years and 65-100% at 15 years. In soft tissue plasmacytoma, the rate of progression to multiple myeloma ranges from 11-30% at 10 years. After treatment, approximately 65% of patients are free of recurrence and do not progress to multiple myeloma, while 22% experience recurrence and 15% of cases evolve to multiple myeloma.

If the plasmacytoma occurs in the soft tissue, the outlook is good, and it is usually possible to eradicate the disease with surgery and or localized radiotherapy. If the plasmacytoma occurs within the bone, most cases respond well to localized radiotherapy.

Overall prognosis for soft tissue plasmacytoma is much better than for solitary bone plasmacytoma. Periodic evaluation for progression and development of multiple myeloma is recommended every 6 months for solitary plasmacytoma of the bone and soft tissue plasmacytoma.

• Prior to December 9, 2018, this condition was evaluated under diagnostic code 7799-7709.

• A 100 percent evaluation shall continue beyond the cessation of any surgical therapy, radiation therapy, antineoplastic chemotherapy, or other therapeutic procedures (including autologous stem cell transplantation). Six months after discontinuance of such treatment, the appropriate disability rating shall be determined by mandatory VA examination. Any change in evaluation based upon that or any subsequent examination shall be subject to the provisions of 38 CFR 3.105(e). If there has been no recurrence, rate residuals under the appropriate diagnostic codes.

• Rate a solitary plasmacytoma that has developed into multiple myeloma as symptomatic multiple myeloma.

• Rate residuals of plasma cell dysplasia (e.g., thrombosis) and adverse effects of medical treatment (e.g., neuropathy) under the appropriate diagnostic codes.