Plasmacytoma is a rare type of cancer that forms tumors of plasma cells in the bone marrow or soft tissues. Plasma cells are white blood cells that help the body fight infection. There are some treatment options for people with this condition.

Bone plasmacytoma is the most common form, but it still makes up only 2–5% of all malignancies affecting plasma cells. The causes of plasmacytoma remain unknown. Symptoms may vary according to the cancer site but can include bone pain and fatigue.

It is important for people with symptoms of plasmacytoma to see a doctor for assessment because the condition can progress to multiple myeloma.

Read on to learn more about plasmacytoma, including diagnosis, how to treat it, and supportive care that can benefit people with this condition.

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Plasmacytoma is a tumor of the plasma cells found in bone or soft tissues of the body. It can occur as solitary or multiple masses. Plasma cells are part of the immune system — they are white blood cells that produce antibodies and help the body fight infection.

In plasmacytoma, abnormal plasma cells form a tumor. The abnormal plasma cells may also make an antibody protein called M protein that does not help fight infection and can build up in the bone marrow. This M protein buildup can cause the blood to thicken or damage the kidneys.

The following are types of plasmacytoma:

Solitary plasmacytoma of bone (SPB)

This is the most common type of plasmacytoma. Around 70% of all solitary plasmacytoma cases are SPB in the axial skeleton — which refers to the bones within the central core of the body.

In SPB, abnormal plasma cells accumulate in the bone. Tumors develop commonly in the spinal column but can develop in other bones in the body, for example, the arms, pelvis, femur, sternum, or ribs.

Approximately 50% of people with SPB have a high risk of developing multiple myeloma within 2–3 years.

Extramedullary plasmacytoma (EMP)

This develops from plasma cells in the soft tissues, and it represents about a third of solitary plasmacytoma cases. EMP occurs outside the bone marrow and typically appears in the head and neck region.

Learn more about the two main types of solitary plasmacytoma and their causes here.

Multiple solitary plasmacytoma (MSP)

There have been fewer reported cases of this type of plasmacytoma. In about 5% of cases of solitary plasmacytoma, people had a diagnosis of MSP.

An individual’s symptoms may vary depending on the type of plasmacytoma and the location of the tumor.

The primary symptom of SPB is typically pain in bones that contain red bone marrow, such as the ribs or femur. People may also experience compression fractures and bones that break easily.

Although EMP can occur anywhere in the body, around 80–90% appears in the aerodigestive tract — which refers to the upper respiratory and digestive tracts. Consequently, a person can experience the following symptoms:

  • headache
  • nasal discharge
  • sore throat
  • difficulty swallowing
  • pain
  • nosebleeds
  • nasal obstruction

If someone does not seek appropriate medical attention, plasmacytoma can progress to multiple myeloma.

A doctor will take a thorough medical history and perform a physical exam.

They may also order the following tests to help them with their diagnosis:

  • Laboratory test: This can involve testing blood or urine for the presence of monoclonal protein. This M protein is an antibody.
  • Imaging studies: X-rays, CT scans, and MRI scans can help a doctor identify tumors in the bones or soft tissues.
  • Biopsies: If the doctor identifies a tumor, they can take a tissue sample to look for abnormal plasma cells. They may also take a bone marrow biopsy to rule out a diagnosis of multiple myeloma.

A doctor may base a diagnosis of plasmacytoma on the following criteria:

  • the person has no other signs of multiple myeloma, such as kidney damage
  • there is a solitary tumor that consists of abnormal plasma cells
  • the biopsy shows that less than 10% of the bone marrow consists of abnormal plasma cells

Doctors may treat plasmacytoma with radiation therapy, surgery, and chemotherapy.


Local radiotherapy is usually the treatment of choice in people with SPB and EMP. The therapy uses high-energy radiation to kill tumor cells. Doctors may give a person the treatment over many days to reduce side effects.


Surgery combined with radiotherapy helps people live longer and increases progression-free survival (PFS). PFS refers to the duration of time that patients live with the disease, but it does not get worse during and after treatment.

It is best to combine surgery with radiotherapy because, on its own, surgery shows increased rates of disease recurrence.

Doctors may use surgery if an individual presents with spinal instability, neurological involvement, or there is a high risk of a fracture occurring.


Doctors may not use chemotherapy for plasmacytomas.

Often, it shows no beneficial effect and does not help prevent complications. Also, it does not stop plasmacytoma from progressing to multiple myeloma, but it may slow down the progression.

In cases where tumors have not responded to radiotherapy or are greater than 5 centimeters in length, doctors may consider chemotherapy as additional therapy and give it after the initial treatment. This is known as adjuvant therapy.

Autologous Stem Cell Transplantation (ASCT)

ASCT uses bone marrow from the person’s body rather than a donor. Doctors harvest the person’s stem cells before they undergo cancer treatment. Following treatment, they receive an infusion of their own stem cells, which travel to the bone marrow and begin creating new blood cells.

Guidelines indicate ASCT for people with a high risk of recurrent plasmacytoma or for those with large numbers of solitary plasmacytoma. Some clinical trials have shown promising results in these groups.

If an individual has plasmacytoma or multiple myeloma, supportive care may help improve their quality of life and ease their symptoms. This can include:

  • physical therapy and exercise programs
  • nutritional guidance
  • stress relief through meditation, massage, or yoga
  • acupuncture
  • emotional and spiritual health support
  • practical support such as financial assistance and transportation to hospital visits

Doctors may also recommend adjuvant treatments to help manage symptoms and side effects. These can include medications to help with bone or kidney damage, anemia, and blood clotting.

If individuals reach a stage where the disease no longer responds to treatment, they may consider hospice care. This supportive care focuses on improving the quality rather than the length of life. It incorporates pain relief, managing symptoms, and focuses on helping people live as fully as possible.

In around 50% of cases, people with SBP can progress to multiple myeloma. With EMP, the progression occurs in 15% of cases. The median time of plasmacytoma progressing to multiple myeloma is 2–3 years.

For people with solitary plasmacytoma, their 5-year relative survival rate is 78%. This means that almost 8 in 10 people with solitary plasmacytoma live for at least five years following their diagnosis. However, if the condition progresses to multiple myeloma, the survival rate drops to 55%.

It is important to note that various factors can affect a person’s outlook. These include:

  • cytogenetics of the tumor — this refers to changes in the chromosomes of the tumor
  • amounts of proteins and other substances
  • kidney function
  • age
  • a person’s overall health

People with plasmacytoma may require life-long follow-up treatment.

Plasmacytoma is a rare type of cancer that affects the plasma cells. Usually, it develops in the bone marrow, but it can also happen in soft tissues. It can progress to multiple myeloma in some cases, but doctors carefully monitor people to limit this occurrence.

The primary treatment for plasmacytoma is radiotherapy, although surgery is sometimes an option. Unfortunately, chemotherapy is not generally beneficial for this type of cancer.

If an individual has any plasmacytoma symptoms, such as unexplained bone pain, they should make an appointment with a doctor who can rule out any serious causes.