Histiocytoma

What is human histiocytoma?

A histiocytoma is a tumor that contains histiocytes (normal immune cells). Histiocytes are located in many parts of your body, including your bone marrow, blood stream, skin, lungs, liver, spleen and lymph nodes. Sometimes, histiocytes travel to tissues where they’re not normally found and cause tumors (histiocytomas).

Is a histiocytoma cancerous?

It depends on the type of histiocytoma you have. Some are benign (harmless), and some are malignant (cancerous).

What are the different types of histiocytomas?

There are different types of histiocytomas, including:

• Undifferentiated pleomorphic sarcoma (UPS).Also referred to as malignant fibrous histiocytoma, this is a type of cancer that mostly develops in soft tissue. In some cases, it can form in bone. Affecting mostly older adults, pleomorphic sarcoma can occur anywhere in your body, but it most often develops in your arms, legs and abdomen. Sometimes, sarcomas can occur in areas that have been targeted by radiation therapy in the past. These tumors usually grow rapidly and metastasize (spread to other parts of your body).
• Benign fibrous histiocytoma (BFH).One of the most common soft tissue lesions, benign fibrous histiocytomas appear as fibrous masses. They can occur anywhere in your body. Unlike pleomorphic sarcomas, benign soft tissue tumors and benign bone tumors aren’t cancerous. However, they still require treatment in most cases.
• Angiomatoid fibrous histiocytoma (AMFH).A rare type of tumor, angiomatoid fibrous histiocytoma usually affects children and young adults. This slow-growing mass is often located in your arms or legs. Most people with angiomatoid fibrous histiocytoma have little to no pain, and the condition is sometimes mistaken for a hematoma (when blood collects beneath the surface of your skin). This type of tumor is generally treatable. In 1% of cases, angiomatoid fibrous histiocytoma can spread to distant parts of your body.
• Cutaneous histiocytoma.Also called a dermatofibroma, or superficial benign fibrous histiocytoma, this type of tumor usually affects the skin on your lower legs. The condition is more common in women than men. Removal isn’t required unless you experience problematic symptoms.

What’s the difference between a histiocytoma and a mast cell tumor?

While a histiocytoma is filled with histiocytes, a mast cell tumor is filled with mast cells. Mast cells originate in your bone marrow and can be found in your connective tissues.

Where does angiomatoid fibrous histiocytoma occur?

Angiomatoid fibrous histiocytoma primarily occurs in the hands, feet, arms or legs of children and young adults. In very rare cases, these tumors have been found in brains, bones and lungs.

Who does histiocytoma affect?

It depends on the type of histiocytoma. For example, undifferentiated pleomorphic sarcoma occurs more commonly in men than women — and the risk of developing the condition increases with age. However, angiomatoid fibrous histiocytomas typically occur in children, adolescents and young adults. And, cutaneous histiocytoma is slightly more common in women, and it usually appears in early or mid-adulthood.

How common is histiocytoma?

There are different kinds of histiocytomas, ranging from common to rare. Benign fibrous histiocytomas and cutaneous histiocytomas are both fairly common. Undifferentiated pleomorphic sarcoma is less common, but it’s still responsible for 20% to 30% of all soft tissue sarcomas. Angiomatoid fibrous histiocytomas are considered rare.

What are the symptoms of histiocytoma?

Symptoms can vary depending on what type of histiocytoma you have:

Undifferentiated pleomorphic sarcoma

• A lump that grows larger.
• Pain.
• Numbness.
• Tingling.
• Swelling in your hand or foot.
• Fever.
• Loss of appetite.
• Constipation.
• Weight loss.

Benign fibrous histiocytoma

• A growing lump or area of swelling.
• Localized pain.

Note: Benign fibrous histiocytoma rarely occurs in your mouth. But when it does, you may experience dysphasia (difficulty swallowing), dyspnea (shortness of breath) or difficulty speaking.

Angiomatoid fibrous histiocytoma

• Fever.
• Weight loss.
• Anemia.
• Pain.
• Tenderness.

Cutaneous histiocytoma

• Dark-colored spot on your skin (usually on your lower legs).
• Raised bump.

What causes histiocytoma?

These tumors are sometimes linked to chemotherapy, radiation or certain medical conditions, such as Paget’s disease of the breast. They can also appear after trauma or injury. However, experts aren’t exactly sure what causes histiocytoma to begin with.

How is histiocytoma diagnosed?

Your healthcare provider will perform a visual examination and ask you about your symptoms. They may also order tests, which may include:

• Dermoscopy.Your healthcare provider uses a handheld visual device to closely examine any lesions or bumps.
• X-rays.These images are used to take a closer look at bone and dense tissue.
• Ultrasound.This type of imaging test helps your medical team see the soft tissues inside of your body.
• Magnetic resonance imaging (MRI).An MRI may be necessary for a detailed look at cartilage and bone.
• Biopsy.To confirm your diagnosis, your healthcare provider may take a sample of tissue and send it to a lab for testing.

These assessments can help your healthcare provider know the difference between histiocytomas and conditions that can be mistaken for tumors.

Should a histiocytoma be removed?

It depends. If the lesion is potentially malignant, then your healthcare provider may recommend surgical histiocytoma removal. Some histiocytomas, such as dermatofibromas, don’t require removal.

How is histiocytoma treated?

Your recommended treatment depends on a few factors, such as the type of histiocytoma, its size and location. Malignant histiocytomas are usually surgically removed. Then, chemotherapy or radiation therapy is used to kill any remaining problematic cells. In some cases, your healthcare provider may recommend radiation therapy or chemotherapy first to shrink the tumor before removal.

Can histiocytoma be cured?

Yes. In many cases, even malignant histiocytoma can be cured. Prompt treatment gives you the best chance for a successful recovery.

Are there side effects of treatment?

As with any treatment, there are potential side effects. They can vary depending on the type of treatment you receive:

Surgery

• Pain.
• Infection.
• Nausea and vomiting.
• Blood clots.
• Soreness around the incision site.
• Bleeding.
• Allergic reaction to the anesthesia.

Chemotherapy

• Tiredness.
• Hair loss.
• Infection.
• Bruising easily.
• Anemia.
• Diarrhea.
• Constipation.
• Weight changes.
• Fertility problems.
• Mood changes.

Radiation therapy

• Tiredness.
• Skin changes.

How can I reduce my risk for histiocytoma?

Because exact histiocytoma causes are unclear, it may not be possible to fully prevent it from occurring. However, you can reduce the risk of many sarcomas by making healthy lifestyle choices, like eating a balanced diet, exercising regularly and avoiding tobacco products.

Is angiomatoid fibrous histiocytoma fatal?

While angiomatoid fibrous histiocytoma can be fatal if it spreads to other areas of your body, it’s usually treated successfully when detected early. In most cases, this type of tumor is slow growing, so the tumor can often be removed before spreading to other parts of your body.

When should I see my healthcare provider?

Anytime you notice an abnormal lump or a skin change, schedule an appointment with your healthcare provider. They can run tests to determine exactly what’s causing it. Whether it’s histiocytoma or another health issue, they can build a personalized plan to treat the lesion and ease your symptoms.

Is angiomatoid fibrous histiocytoma related to Langerhan’s cell histiocytosis?

While angiomatoid fibrous histiocytoma and Langerhans cell histiocytosis are both caused by abnormal histiocyte production, the two conditions aren’t related.

A note from Cleveland Clinic

Not much is known about why histiocytomas form, and the uncertainty can be scary. But prompt diagnosis and treatment gives you the best chance for making a full recovery.