Overview of Enlarged Retroperitoneal Lymph Nodes

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Lymph nodes are small, bean-shaped structures located all over the body. They are part of the lymph system, a network to the vessels that function like immune outposts, filtering fluids from tissues to help neutralize infection and minimize toxic exposure.

When lymph nodes of the abdominal cavity (known as the retroperitoneum) become enlarged, there are many potential reasons for this, and not all of them are cancerous. In fact, in most cases, cancer is the last concern on the list.

Still, there are certain patterns of enlargement that are concerning and require more extensive evaluation, including imaging studies and biopsies.

Common Causes of Swollen Retroperitoneal Lymph Nodes
Verywell / Gary Ferster

Primary Causes

Retroperitoneal lymph nodes are located in a specific part of the abdominal cavity immediately behind the intestine that is closer to your backbone than your belly button. The swelling of the nodes themselves is referred to as lymphadenopathy.

Unlike other types of lymph nodes, retroperitoneal lymph nodes generally cannot be felt or seen when enlarged. Because of this, doctors will often only discover an enlargement after conducting an imaging study such as a computed tomography (CT) scan of the abdomen and pelvis.

Oftentimes, the swelling will be the result of an infection, manifesting with either a diffuse pattern if the underlying infection is systemic (involving the whole body) or a constrained pattern if the infection is localized.

Among some of the more common causes of swollen retroperitoneal lymph nodes:

  • Infections such as tuberculosis
  • Inflammatory conditions such as sarcoidosis
  • Cancers that spread (metastasize) to the lymph nodes
  • Blood cancers that develop in the lymph nodes or spread to the lymph nodes
  • Rare, noncancerous conditions like Castleman disease which cause the overgrowth of lymph nodes

Although swollen lymph nodes in and of themselves can tell us little about the underlying illness, there are some red flags doctors will look for.

Certain patterns of enlargement are worrisome, such as those in which a large mass of lymph nodes appears stuck together and consolidated on imaging studies. Patterns like this are often suggestive of a metastatic malignancy.

In instances like these, the doctor may recommend a biopsy to obtain a tissue sample for evaluation or an imaging study known as positron emission tomography (PET), which is able to detect a metastatic malignancy better than other imaging technologies.

Secondary Causes

More often than not, the cause of swollen retroperitoneal lymph nodes will be secondary, meaning that they are collaterally affected by a disease or disorder affecting an organ within or near the retroperitoneum. These include such as organs as:

  • Adrenal glands
  • Ascending or descending colon and duodenum
  • Esophagus
  • Kidneys and ureters
  • Pancreas

Sometimes a disease that affects one of these organs will also affect the associated lymph nodes and vice versa.

For instance, the ureters carry urine from the kidney to the bladder. Masses in this area can block a ureter, causing urinary tract symptoms that trigger the inflammation and the production of inflammatory cytokines. When this happens, retroperitoneal lymphadenopathy will almost invariably occur.


Cancer is clearly the most concerning cause of retroperitoneal lymphadenopathy. Two of the most common malignancies associated with this are lymphoma and testicular cancer.


Lymphomas are a group of cancers of which are considered lymphoproliferative (meaning that it causes the excessive production of white blood cells called lymphocytes). Lymphomas usually start in the lymph nodes; retroperitoneal lymph nodes are typically affected. There are two main categories of lymphoma:

With HL, the pattern of enlargement is typically defined, moving from one lymph node group to the next. With NHL, the distribution is more scattershot and may involve distant lymph nodes and organ systems (primarily the gastrointestinal tract).

Moreover, with lymphoma, a CT scan will typically reveal that both the liver and spleen are enlarged along with the retroperitoneal lymph nodes.

Testicular Cancer

Cancers can often metastasize from a primary tumor to retroperitoneal lymph nodes. One such cancer is testicular cancer.

As with lymphoma, metastatic testicular cancer usually spreads in a predictable fashion, moving progressively through the lymphatic system and typically establishing itself in the nodes of retroperitoneum. In some instances, an operation called a retroperitoneal lymph node dissection may be used to help manage the advanced disease.

A Word From Verywell

When enlarged lymph nodes in the retroperitoneum are identified, the significance of this finding depends on all of the other information, including the medical history of the individual with the enlarged nodes.

One important aspect of enlarged nodes in this particular location is that they are quite isolated from the rest of the body and are not as easily detected as lymph nodes in the neck, armpits or groin, for instance.

Sometimes lymph nodes are "borderline-enlarged" on imaging, meaning they are slightly larger than usual, but not necessarily a cause for concern. In these cases, there may be follow-up imaging performed and comparison to past studies to see if there has been enlargement in the interim.

Always talk to your healthcare team if you have questions about findings such as enlarged retroperitoneal lymph nodes or questions about the significance of these findings.

Frequently Asked Questions

  • What are the survival rates for lymphoma?

    For Hodgkin's lymphoma, the five-year survival rates are:

    • Localized (has not spread): 94%
    • Regional (spread to nearby tissues): 91%
    • Metastatic (spread to distant organs): 81%

    For non-Hodgkin's lymphoma, the rates are:

    • Localized: 73%
    • Regional: 73%
    • Metastatic: 57%
  • What are the survival rates for testicular cancer?

    The relative five-year survival rate for testicular cancer that stays localized to the testicles is 99%. If the cancer spreads to nearby structures or lymph nodes, the survival rate is 96%, and if it metastasizes to distant organs or lymph nodes, the survival rate is 73%.

  • Can retroperitoneal lymph nodes be removed?

    Yes, retroperitoneal lymph nodes can be removed, and this is often used as a treatment option for testicular cancer. It can also be used to diagnose stages of cancer. The procedure is called a retroperitoneal lymph node dissection.

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9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Merck Manual. Swollen lymph nodes.

  3. Gallamini A, Zwarthoed C, Borra A. Positron emission tomography (PET) in oncology. Cancers (Basel). 2014;6(4):1821-89. doi:10.3390/cancers6041821

  4. Coursey moreno C, Small WC, Camacho JC, et al. Testicular tumors: what radiologists need to know--differential diagnosis, staging, and management. Radiographics. 2015;35(2):400-15. doi:10.1148/rg.352140097

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  6. American Cancer Society. Survival rates for Hodgkin lymphoma.

  7. American Cancer Society. Survival rates and factors that affect prognosis (outlook) for non-Hodgkin lymphoma.

  8. American Cancer Society. Testicular cancer survival rates.

  9. Cleveland Clinic. Retroperitoneal lymph nodes dissection.

Additional Reading
  • Lymph Nodes. Lawrence M. Weiss. Cambridge University Press, Apr 28, 2008
  • Non-Hodgkin Lymphomas. James Armitage et al. Lippincott Williams & Wilkins, Aug 8, 2013.
  • Radiopaedia.org. Retroperitoneal organs (mnemonic).