Cancer Lymphoma Symptoms Print Overview of Enlarged Retroperitoneal Lymph Nodes By Indranil Mallick, MD twitter linkedin Indranil Mallick, MD, DNB, is a radiation oncologist with a special interest in lymphoma. Learn about our editorial process Indranil Mallick, MD Medically reviewed by Medically reviewed by Doru Paul, MD on December 01, 2019 Doru Paul, MD, is board-certified in internal medicine, medical oncology, and hematology. Learn about our Medical Review Board Doru Paul, MD Updated on December 07, 2019 More in Lymphoma Symptoms Hodgkin Lymphoma Non-Hodgkin Lymphoma Causes & Risk Factors Diagnosis Treatment Living With In This Article Table of Contents Expand Primary Causes Secondary Causes Cancers Lymphoma Testicular Cancer View All Back To Top 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. 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 tuberculosisInflammatory conditions such as sarcoidosisCancers that spread (metastasize) to the lymph nodesBlood cancers that develop in the lymph nodes or spread to the lymph nodesRare, non-cancerous 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 glandsAscending or descending colon and duodenumEsophagusKidneys and uretersPancreas 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. Cancers Cancer is clearly the most concerning cause of retroperitoneal lymphadenopathy. Two of the most common malignancies associated with this are lymphoma and testicular cancer. Lymphoma 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: Hodgkin’s lymphoma (HL), which is primarily nodal (affect the lymph nodes)Non-Hodgkin’s lymphoma (NHL), which is nodal and extranodal (affecting other organs) 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 health care team if you have questions about findings such as enlarged retroperitoneal lymph nodes or questions about the significance of these findings. How Lymphadenopathy Is Diagnosed Was this page helpful? Thanks for your feedback! Limiting processed foods and red meats can help ward off cancer risk. These recipes focus on antioxidant-rich foods to better protect you and your loved ones. Sign up and get your guide! Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article 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. Gaddey H, Riegel A. Unexplained lymphadenopathy: evaluation and differential diagnosis. Am Fam Physician. 2016;94(11):896-903. December 1, 2016. Merck Manual. Swollen lymph nodes. Updated July 2019. Gallamini A, Zwarthoed C, Borra A. Positron Emission Tomography (PET) in oncology. Cancers (Basel). 2014;6(4):1821-89. doi:10.3390/cancers6041821 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 American Cancer Society. Tests for Non-Hodgkin Lymphoma. Updated August 1, 2018. 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).