Colorectal lymphoma, a rare type of colon cancer, can be tough to pinpoint. Its symptoms may be mistaken for those of other illnesses, so colorectal lymphoma may not be a top-of-mind diagnosis. That’s why it’s important to educate yourself about this uncommon type of lymphoma that affects the colon and rectum.

Continue reading to learn more about the causes, symptoms, and treatment of colorectal lymphoma.

What Is Colorectal Lymphoma?

Lymphoma is a group of blood cancers involving your lymphatic system (part of your body’s germ-fighting system). Although it’s considered a blood cancer, lymphoma can affect almost any organ in your body. When it affects your colon or rectum, it’s known as primary colorectal lymphoma.

Colorectal lymphoma is a type of gastrointestinal lymphoma, which affects the digestive tract. “Colorectal” refers to your colon, which is also known as the large intestine or large bowel, and your rectum, the passage that connects your colon to your anus. Colorectal lymphoma makes up just 0.2 percent to 1 percent of all cancers of the colon, according to the World Journal of Surgical Oncology.

Types of Colorectal Lymphoma

There are two main types of lymphoma — Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). Lymphoma types are further classified based on the immune cells that are growing out of control. Most types of NHL involve B cells but can also involve T cells or natural killer cells.

Non-Hodgkin lymphoma is the most common type of colorectal lymphoma. B-cell lymphoma of the colon is the third most common type of colon cancer, yet its incidence rate (how often it occurs in the population every year) is less than 0.5 percent.

The most common subtype of colorectal lymphoma is diffuse large cell B-cell lymphoma (DLBCL), which grows and spreads quickly. The second most common subtype is mantle cell lymphoma — a rare type of B cell lymphoma. A 2019 study of 52 people with colorectal lymphoma found that 48 percent had DLBCL and 25 percent had mantle cell lymphoma.

Usually, colorectal lymphoma affects the cecum, the part of the colon that connects to the small intestine. The ascending colon (the right side) is the next most common area affected.

It’s possible for another type of lymphoma from another part of the body to spread to the colon or rectum, but this is very rare.

Who Gets Colorectal Lymphoma?

Colorectal lymphoma usually occurs in males between the ages of 40 and 70, according to the World Journal of Surgical Oncology. However, it has been diagnosed in people as young as 13 years.

Groups with an increased risk of developing colorectal lymphoma include people:

• Who’ve had an organ transplant
• With inflammatory bowel disease
• Infected with human immunodeficiency virus (HIV)

Symptoms of Colorectal Lymphoma

The symptoms of colorectal lymphoma depend on where the cancer starts to grow. The symptoms are usually nonspecific — meaning they’re general symptoms that could be caused by other conditions. The most common symptoms of colorectal lymphoma include:

• Abdominal pain
• Weight loss
• Loss of appetite
• Diarrhea
• A mass in the abdomen
• Blood in the stool
• Changes in bowel habits

If the cancer grows large enough, it can lead to a bowel obstruction (blockage) and cause nausea and vomiting. You can also get an infection called acute peritonitis if you develop a bowel perforation (a hole in your intestines).

People with colorectal lymphoma rarely experience a group of lymphoma symptoms known as B symptoms, including fever and night sweats.

Staging of Colorectal Lymphoma

During your diagnosis, your doctor will determine your cancer’s stage. The stage is based on the cancer’s location and size and whether it has spread to other parts of the body.

In colorectal lymphoma, the most common staging system is the Lugano classification based on the Ann Arbor system. Cancer stages are sometimes noted with Roman numerals, as stages I through IV. The stages of the Lugano classification and areas involved are as follows:

• Stage 1 — A single lymph region or a single extranodal site (outside of lymph nodes)
• Stage 2 — Two or more lymph regions or extranodal sites located on the same side of the diaphragm (the muscle below your lungs that helps you breathe)
• Stage 3 — Lymph nodes, the spleen, and lymph regions on both sides of the diaphragm
• Stage 4 — Sites outside the lymph nodes, such as bone marrow, the central nervous system, or other internal organs

If the cancer involves an extranodal site, it might be classified as stage 1E, 2E, or 3E. When the spleen is involved, the stage may be noted as stage 3S.

Diagnosis of Colorectal Lymphoma

Many people with colorectal lymphoma don’t get diagnosed until they have an emergency that requires surgery, such as a perforated or obstructed bowel or bleeding. Because of the nonspecific symptoms, the presence of this type of cancer might not be considered earlier.

Colorectal lymphoma can be diagnosed with a colonoscopy. During this procedure, a doctor uses a flexible tube with a camera to examine the inside of your colon, rectum, and anus.

Your medical team may also order imaging tests to help diagnose colorectal lymphoma, such as:

• CT scan, which creates a detailed image of your tissues using a series of X-rays and a computer
• Barium enema, a procedure that uses a chemical called barium to produce a detailed X-ray image of the colon and rectum

Treatment of Colorectal Lymphoma

Colorectal lymphoma treatment usually includes surgery and chemotherapy. However, because colorectal lymphoma is so rare, clinical trials haven’t compared different treatments.

If you have early-stage disease (stage 1 or 2), your options might involve surgical resection (removal) of the tumor followed by chemotherapy. If you have a fast-growing or advanced-stage cancer, you may receive chemotherapy first. People with any stage may need surgery to treat complications like bowel obstruction or perforation.

Chemotherapy can be used before or after surgery to kill cancer cells and help shrink the tumor. A common chemotherapy regimen used for colorectal lymphoma is known as CHOP. The CHOP regimen includes the following chemotherapy drugs:

• Cyclophosphamide
• Doxorubicin (also known as hydroxydaunorubicin)
• Vincristine (formerly sold as Oncovin)
• Prednisone

CHOP treatment is usually given in six to eight three-week cycles.

A targeted therapy called rituximab (Rituxan) may be added to your cancer treatment if you have DLBCL that tests positive for a protein called CD20. Adding rituximab to CHOP (R-CHOP) may improve outcomes.

Talk to your lymphoma care team about the best treatment option for you.

Outlook for Colorectal Lymphoma

Your outlook — also known as prognosis — depends on the individual factors of your cancer, such as:

• Type of lymphoma
• Stage at diagnosis
• Need for urgent surgery

Since colorectal lymphoma is a rare disease, few studies have examined the average outlook of people with this type of cancer. A 2011 study found that 57 percent of people with colorectal lymphoma lived at least five years after diagnosis — also known as the five-year survival rate. Characteristics associated with a better outlook include:

• Being younger than 60 when diagnosed
• Receiving surgical treatment
• Having tumors located in regions other than the rectum

The 2019 study of 52 people with colorectal lymphoma found that those who were immunocompromised (had a faulty immune system) didn’t live as long as people whose immune systems worked properly.

Talk to your lymphoma care team about your prognosis based on your overall health and the specifics of your cancer. They can help you find the treatment plan that can best manage your cancer and improve your quality of life.

Talk With Others Who Understand

MyLymphomaTeam is the social network for people with lymphoma and their loved ones. More than 15,000 members understand what it’s like to face lymphoma and can provide support and answers.

Are you living with colorectal lymphoma? Was it difficult to get your diagnosis? Share your experience or post a comment on your Activities page to start a conversation.