What you need to know about Castleman Disease

Have you ever had a lump, what we call a "lump," on your neck, armpit, or groin? Sometimes, lumps like this swell up when you have a common cold or some kind of infection. That's normal. But if you have swollen lumps like this for no reason, for a long time, and you're also feeling tired and losing weight, you should be a little concerned. Today, we're going to talk about a rare condition that can be suspected at such times. That's Castleman Disease.

Simply put, what is Castleman Disease?

Imagine that our body is like a country. Then our immune system is the army that protects that country. When a germ (enemy) enters the body from the outside, this army goes into battle and defeats that enemy. When the battle is over, the army goes back to the barracks and becomes silent. This is what happens in the body of a healthy person.

But with someone with Castleman's disease, it's different. What happens here is that the army that went to war, the immune system, doesn't calm down even after the battle is over. They stay active. It's like they're always ready for war. This causes long-term inflammation in the body. This can damage our organs.

Meanwhile, our lymph nodes, those little things, are like military bases. They do a lot of work, like filtering out germs and storing immune cells. Now, because the immune system is constantly working, these lymph nodes are also constantly working. As a result, the cells in them start to grow excessively. That's why the lymph nodes swell in Castleman's disease. It's not just swelling, it even causes changes in the tissue of those lymph nodes.

What are the main types of Castleman disease?

Casselman disease is divided into two main types. The symptoms and treatments for each are very different. Therefore, it is important to understand these two types precisely.

Are there subtypes of multicentric Castleman disease (MCD)?

Yes, MCD is further divided into several subtypes. This classification is done based on the cause and other conditions that occur with it.

• POEMS-associated MCD: POEMS is a very rare blood disorder. Sometimes MCD can occur together with POEMS.
• HHV-8-associated MCD: This is caused by infection with a virus called Human Herpes Virus-8 (HHV-8). This type is especially common in people who are infected with HIV or who are immunocompromised for other reasons.
• Idiopathic MCD (iMCD): The medical term " idiopathic " means "no cause has been found." The majority of MCD patients have this type. This means that the exact cause is not yet known.

This type of iMCD is further divided into three smaller categories:

1. iMCD associated with TAFRO: TAFRO is a name derived from a combination of several symptoms. That is, Thrombocytopenia (low blood platelets), Anasarca (swelling of the body with water), Fever (fever), Renal dysfunction (weakening of kidney function) and Organomegaly (enlargement of the liver or spleen) are the symptoms that can be seen in this.

2. iMCD with idiopathic plasmacytic lymphadenopathy (iMCD-IPL): In this type, the platelet count may be elevated. There may also be excessive production of antibodies by white blood cells.

3. iMCD, not otherwise specified (iMCD-NOS): Patients with iMCD who are not related to TAFRO and for whom no other specific cause can be found fall into this category.

What could be the symptoms of this disease?

Symptoms vary depending on the type of Castleman's disease you have.

Unicentric Casselman disease (UCD) usually has no symptoms . The only sign is a swollen lymph node (adenoid). Sometimes, symptoms (e.g., pain, shortness of breath) only occur when the swollen node presses on another organ.

However, in multicentric Castleman disease (MCD), the symptoms are more obvious. In addition to swollen glands, you may experience:

• Frequent fever
• Feeling extremely tired and exhausted for no reason (this could also be due to anemia)
• Excessive sweating at night
• Nausea and vomiting
• Unexpected weight loss
• Swelling of the legs, ankles, or abdomen
• Enlarged spleen (splenomegaly) or enlarged liver (hepatomegaly)
• Numbness in the hands and feet (peripheral neuropathy)

Why does this disease occur? Are there any risk factors?

In fact, scientists have not yet found a specific cause for unicentric Castleman disease (UCD) .

Multicentric Castleman disease (MCD) is associated with the aforementioned HHV-8 virus . However, researchers are still investigating whether other infections, gene mutations, or autoimmune responses may be responsible for the unknown type of iMCD.

When it comes to risk factors, there are no known risk factors for UCD and iMCD. However, if you have HIV infection or another weakened immune system, you are at higher risk for developing HHV-8-associated MCD.

Although this disease can develop in people of any age, it is most common in people between the ages of 30 and 60 .

What are the possible complications of this disease?

Castleman disease may slightly increase your risk of developing other conditions, especially cancers , such as lymphoma, a cancer of the lymphatic system.

Additionally, people with UCD are at risk of developing a rare but serious skin condition called paraneoplastic pemphigus (PNP). People with MCD are at increased risk of developing various infections. If left untreated, these infections can cause organ damage and even death.

But don't worry, your doctor will constantly monitor this condition and take the necessary steps to help prevent these complications as much as possible.

How does a doctor accurately diagnose this disease?

Because the symptoms of Castleman's disease are similar to those of other illnesses, such as the common cold or flu, a doctor will first check for common illnesses. Only then will they suspect Castleman's disease and perform specific tests.

The following tests are mainly performed:

• Lab tests: Your blood will be examined under a microscope to check for abnormalities in your blood cell counts and other abnormalities. If HHV-8-associated MCD is suspected, an HIV test may also be done.
• Imaging tests: CT scans and PET scans can help pinpoint where swollen lymph nodes are located in the body. They can also check for enlargement of organs like the liver and spleen.
• Lymph node biopsy: This is the only and most definitive way to confirm the disease . This involves taking a very small piece of tissue from the swollen lymph node and examining it under a microscope. This can then tell for sure if there are any specific cell changes associated with Casselman disease.

What are the treatments for this?

Treatment methods vary completely depending on the type of disease.

Treatment of Unicentric Casselman Disease (UCD)

The main and most successful treatment for UCD is surgical removal of the affected lymph node . In most cases, the disease is completely cured after this surgery.

Sometimes, if the tumor is large, radiation therapy or immunotherapy is given before surgery to shrink it and make it easier to remove.

If the lump is in a location that cannot be removed with surgery, and you have no symptoms, your doctor may decide not to treat it and just observe it. However, for someone who is not a candidate for surgery and still has symptoms, the same treatment as for MCD can be given.

Treatment of multicentric Casselman disease (MCD)

Because MCD is a condition that spreads to multiple parts of the body, it cannot be cured with surgery or radiation therapy. Therefore, other treatments are used. Treatment depends on whether you have HHV-8 and how severe the disease is.

The following treatments are mainly provided:

• Corticosteroids: These medications help control symptoms by reducing inflammation in the body.
• Chemotherapy drugs: These work by controlling the rate at which cells in the lymphatic system grow too quickly. Rituximab is commonly used for HHV-8-associated MCD.
• Immunotherapy: These treatments work by calming your body's overactive immune system. Siltuximab (Sylvant®) is the only drug approved for iMCD.
• Antiviral drugs: If you have HHV-8-associated MCD, you may be given these drugs to control HIV or HHV-8 infection.

What time should I see a doctor?

If you notice a lump or bump on your neck, armpit, or groin that you can feel, be sure to tell your doctor about it.

Also, if the symptoms mentioned in this article, such as unexplained fever, weight loss, and excessive fatigue, persist for several weeks, be sure to seek medical advice.

Is it possible to live with this disease?

The answer to this question depends on the type of Casselman you have.

A person with UCD can expect very good outcomes . When the tumor is surgically removed, the disease is often completely cured. After treatment, this will not affect your normal life expectancy.

The prognosis for people with MCD is a bit complicated . It varies depending on the type and severity of the disease. For some, symptoms can suddenly become severe and life-threatening. For others, symptoms can last a long time, but there is hope. Between 65% and 75% of people diagnosed with MCD live for more than five years . This is improving with new treatments.

There is no simple, one-size-fits-all answer to Casselman disease. It will depend on your experience, the type of disease you have, and whether you have other conditions, such as HIV, TAFRO, or POEMS. Sometimes surgery and constant medical monitoring will be enough. Or you may need to receive multiple treatments throughout your life. So it’s best to talk openly with your doctor about your condition, your treatment, and your future.