What is Solitary Plasmacytoma & How is it Treated?

Plasmacytoma is a malignant tumor where there is accumulation of abnormal plasma cells which grow inside the bony skeleton or the soft tissue of the patient. If the plasmacytoma is present as an inconspicuous solitary mass of abnormal plasma cells, then it is known as Solitary Plasmacytoma, i.e. only one tumor is present; hence the name “solitary.” If it is present as a part of a systemic disorder where there are many small tumors present, then it is known as multiple myeloma which is a blood cancer of the plasma cells. The treatment and prognosis of both these conditions is different. In this article, we are discussing about Solitary Plasmacytoma.

The white blood cells which form from mature B-lymphocytes present in the bone marrow are the plasma cells. The role of plasma cells is protecting the body against diseases and infection by producing immunoglobulins (Ig), which are proteins and are also known as antibodies.

There are 2 types of Solitary Plasmacytoma:

Solitary Extramedullary Plasmacytoma (SEP):- In this type of Solitary Plasmacytoma there is accumulation of abnormal plasma cells in the soft tissue, outside the bone. The development of Solitary Extramedullary Plasmacytoma commonly occurs in the region of head and neck, especially in the nose, sinuses and throat. Other than this, Solitary Extramedullary Plasmacytoma can also develop in the gastrointestinal tract, bladder, lymph nodes, lungs and other organs. The chance of Solitary Extramedullary Plasmacytoma progressing to myeloma is less than 10%.

Solitary Bone Plasmacytoma (SBP): In this type of Solitary Plasmacytoma, there is localized accumulation of abnormal plasma cells in the bone. These tumors commonly develop in the spinal column, but can also occur in the ribs, pelvis, arms, skull, face, femur and sternum. There are some patients (50-70%) with Solitary Bone Plasmacytoma who can develop multiple myeloma in the future, like in about 10 years or so. So patients suffering from this type of plasmacytoma, need to be monitored regularly with x-ray, blood tests and MRI scan.

As of now, there is no known cause of solitary plasmacytoma.

If the patient has solitary bone plasmacytomas, then he/she may suffer from bone fractures or bone pain. Symptoms of solitary plasmacytoma depend on the location of the tumor.

About 25% of the patients with Solitary Extramedullary Plasmacytoma and about 75% of patients with Solitary Bone Plasmacytoma will have an M-protein, which are the abnormal proteins produced by the malignant plasma cells. However, they are small and will disappear after treatment.

Middle-aged and elderly people more commonly tend to develop solitary plasmacytoma. This malignant condition is rarely seen in people under the age of 30. Men more commonly suffer from solitary plasmacytomas than women. Solitary bone plasmacytomas are rare and occur in about 5% of all the plasma cell disorders. SEP is even rarer.

• For diagnosis of Solitary Plasmacytoma, a biopsy is done which reveals a single tumor within the tissue or bone consisting of abnormal plasma cells.
• Bone marrow biopsy does not show any sign of myeloma.
• Imaging tests such as x-rays, magnetic resonance imaging (MRI) scan or Positron Electron Tomography (PET) scan do not reveal any other lesions in the soft tissues or the bone.
• Blood tests do not show any anemia, hypercalcemia or problems with kidney function.

Radiation Therapy for treating Solitary Plasmacytoma: Radiation therapy is the commonly used treatment for both the types of solitary plasmacytoma, as solitary plasmacytomas are localized and there is only one tumor present. In radiation therapy, there is focusing of radiation on the solitary plasmacytoma to destroy the abnormal cancerous cells. The treatment is done for several days.

Chemotherapy for treating Solitary Plasmacytoma: Chemotherapy is not commonly used with radiation therapy in treating solitary plasmacytoma. However, in some patients, chemotherapy is considered.

Surgery for treating Solitary Plasmacytoma: Most of the times, surgery is not required; however, surgery may be needed in patients where the plasmacytoma involves the bone causing skeletal instability and a high risk of fracture. Such patients will have surgery first followed by radiation therapy.

Radiation therapy often gives excellent local and durable control of the solitary plasmacytoma; but there is a risk of recurrence of plasmacytomas or the risk of plasmacytomas progressing to myeloma (especially with SBP). Patients with solitary plasmacytomas need life-long follow-ups consisting of physical examination, urine tests, blood tests, x-rays, PET scan or MRI scan at regular intervals after the treatment for solitary plasmacytoma has been completed.

Also Read:

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• What is Proton Therapy & How Does It Work in the Treatment of Cancer?
• Plasma Cell Leukemia: Causes, Symptoms, Treatment, Prognosis, Risk Factors