An enlarged lymph node, usually inside the chest or abdomen, is the only abnormality for most people with the localized form of Castleman disease (CD). If the enlarged lymph node is in the chest, they may have trouble breathing, a cough, or a feeling of fullness in the chest. CD in the abdomen can cause trouble eating, pain, or just a feeling of fullness. In general, most people with localized CD disease feel well otherwise.

People with multicentric CD have more than one area of enlarged lymph nodes. The involved nodes may be in the chest or abdomen, but multicentric CD disease often affects lymph nodes in the groin, the underarm area, and on the sides of the neck. Multicentric CD can also affect lymphoid tissue of internal organs, causing the liver, spleen, or other organs to enlarge.

In addition, people with either type of CD may have other symptoms. These symptoms, however, occur much more often in multicentric than in localized Castleman disease.

The most common include:

• fever 
• weakness 
• night sweats 
• weight loss 
• loss of appetite 
• nausea and vomiting 
• nerve damage that leads to numbness and weakness (neuropathy)

Amyloidosis, a disease where abnormal proteins are deposited in tissues, can occur in CD. This can lead to kidney damage, heart damage, nerve damage, and intestinal problems, mainly diarrhea. Amyloidosis can go away if the CD disease is successfully treated.

Imaging studies

Computed tomography

The computed tomography or CT scan is an x-ray procedure that produces detailed cross-sectional images of your body. Instead of taking one picture, as does a conventional x-ray, a CT scanner takes many pictures as it rotates around you. A computer then combines these pictures into an image of a slice of your body. The machine takes pictures of multiple slices of the part of your body that is being studied. This test can help tell if Castleman disease is in only one lymph node or many.

Before the first set of pictures is taken you may be asked to drink 1 or 2 pints of a contrast agent. This helps outline the intestine so that certain areas are not mistaken for tumors. You may also receive an intravenous (IV) line through which a different kind of contrast dye is injected. This helps better outline structures in your body.

The injection can cause some flushing (redness and warm feeling that may last hours to days). A few people are allergic to the dye and get hives. Rarely, more serious reactions like trouble breathing and low blood pressure can occur. You can be given medicine to prevent and treat allergic reactions. Be sure to tell your doctor if you have ever had a reaction to any contrast material used for x-rays.

CT scans take longer than regular x-rays because you need to lie still on a table for 15 to 30 minutes while they are being done. But just like other computerized devices, they are getting faster and your stay might be pleasantly short. Also, you might feel a bit confined by the equipment you lie within while the pictures are being taken.

CT scans can also be used to guide a biopsy needle precisely into a lymph node that is enlarged from things like infection, lymphoma, metastatic cancer, or Castleman disease (CD). For this procedure, called a CT-guided needle biopsy, the patient remains on the CT scanning table while a radiologist advances a biopsy needle toward the location of the lymph node. CT scans are repeated until the doctors are confident that the needle is within the lymph node. A fine needle biopsy sample (tiny fragments of tissue) or a core needle biopsy sample (a thin cylinder of tissue about ½-inch long and less than 1/8-inch in diameter) is removed and examined under a microscope. Although a needle biopsy cannot accurately diagnose CD by itself, it is sometimes useful in diagnosing or excluding other diseases that can cause large lymph nodes.

Magnetic resonance imaging

Magnetic resonance imaging (MRI) scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed and then released in a pattern formed by the type of body tissue and by certain diseases. A computer translates the pattern of radio waves given off by the tissues into a very detailed image of parts of the body. Not only does this produce cross-sectional slices of the body like a CT scanner, it can also produce slices that are parallel with the length of your body. A contrast material might be injected just as with CT scans but is used less often.

MRI scans are very helpful in looking at the brain and spinal cord. MRI scans are a little more uncomfortable than CT scans. First, they take longer -- often up to an hour. Also, you have to be placed inside tube-like equipment, which is confining and can upset people with a fear of enclosed spaces. The machine also makes a thumping noise that you may find disturbing. Some places provide headphones with music to block this out.

Chest x-ray

This may be done to find out whether there are enlarged lymph nodes in your chest -- usually in the center part called the mediastinum.

Gallium scan

For this test, the radiologist injects a radioactive chemical called gallium into a vein. The chemical is attracted to areas of the body affected by certain diseases such as lymphoma or Castleman disease (CD). A special camera can then locate the gallium. A gallium scan can find unsuspected sites of CD disease, but it is not always reliable since the radioactive gallium may not be taken up by all of the lymph nodes affected by CD.

Positron emission tomography

This test, a PET scan, has been helpful in finding small collections of cancer cells that may not be visible on CT scan. It is not used frequently to diagnose Castleman disease . In the PET scan, radioactive glucose (sugar) is injected into the patient’s vein. Because cancer cells use sugar much faster than normal cells, the cancerous tissue takes up the radioactive material. A scanner is used to spot the radioactive deposits. The CD cells seem to take up glucose more than normal cells (but less than most cancer cells). Often the PET scan is combined with a CT scan. This helps decide if abnormalities seen on the CT scan are CD, cancer, or something else.

Lymph node biopsy

Castleman disease (CD) is diagnosed by removing the enlarged lymph node and examining it under the microscope. This procedure is called a biopsy. If the lymph node is near the skin surface, the surgeon can remove the node under local anesthesia (using numbing medication). The surgeon makes a small incision over the enlarged lymph node, removes the node, and then stitches the incision closed. If the procedure removes the entire lymph node, it is called an excisional biopsy. If only part of the node is removed, it is called an incisional biopsy.

Sometimes lymph nodes are biopsied by putting a needle into the node. A very thin needle can remove tiny fragments of tissue, and a slightly larger needle can remove a cylinder-shaped core or tissue. Although needle biopsies are useful for diagnosing some types of cancers, it is not possible to diagnose CD accurately by needle biopsies alone.

If the lymph node is in the chest or the abdomen, then the surgeon may need to make a large incision to get into either of these places. This is more like major surgery but it may be necessary to know what is causing the lymph node to enlarge. Sometimes, lymph nodes in the chest can be removed by mediastinoscopy. In this procedure, the surgeon can biopsy the lymph nodes with special instruments through a hollow tube called a mediastinoscope, which is inserted through a small incision just above the breastbone (sternum).

All biopsy specimens are examined under a microscope by a pathologist (a doctor who is specially trained to diagnose disease). The pathologist looks at the size, shape, and arrangement of the cells in the lymph node. Since the disease is so rare, the pathologist may ask another pathologist with additional training in the diagnosis of blood and lymph node diseases (called a hematopathologist) to look at the biopsy. Sometimes it is hard to tell whether the lymph node is affected by CD or by lymphoma. In these cases, other tests may be done on the lymph node tissue.

Immunohistochemistry

In this test, a part of the biopsy sample is treated with special manmade antibodies. The cells are treated so that certain types of cells change color. The color change can be seen under a microscope. It may be helpful in telling whether there is Castleman disease or lymphoma in the lymph node.

Flow cytometry

The cells being examined by this test are treated with special manmade antibodies and passed in front of a laser beam. Each antibody sticks only to certain types of cells. If the sample contains those cells, the laser light causes them to give off light of a different color. The intensity of each color is measured exactly and analyzed by a computer. This test can help determine whether lymph node swelling is caused by lymphoma, some other cancer, or a non-cancerous disease like Castleman disease.