What Are Lymph Nodes? Enlargement and Their Role in Gynecologic Cancers

Terms such as lymph node, lymphadenopathy, reactive lymph node, and lymph node involvement found in ultrasound, MRI, PET/CT, or pathology reports may cause concern and raise questions among patients. People diagnosed with cancer, in particular, often want to know whether these findings indicate that the disease has spread.

Lymph nodes are a natural part of the immune system. However, they also play an important role in assessing the spread of certain types of cancer. Therefore, identifying a lymph node on an imaging report and detecting cancer cells within a lymph node are two different findings.

What Are Lymph Nodes and What Do They Do?

Lymph nodes, also known as lymph glands, are small structures that play an important role in the immune system. They filter lymphatic fluid and help the body defend itself against microorganisms and foreign substances. They are found throughout the body, particularly in the neck, armpits, groin, chest, and abdomen.

In gynecologic cancers, lymph nodes in two regions are particularly important:

Pelvic lymph nodes: Located within the pelvis, along the blood vessels surrounding the uterus and other pelvic organs.
Para-aortic lymph nodes: Located in the back of the abdomen, around the aorta, the body’s main artery, and nearby blood vessels.

These regions are among the areas to which certain gynecologic cancers may spread through the lymphatic system.

What Does It Mean When Lymph Nodes Are Mentioned in an Ultrasound, MRI, or PET/CT Report?

The mention of lymph nodes in imaging reports does not necessarily indicate the presence of disease. What matters is the size, shape, internal structure, location of the lymph node, and any accompanying findings.

Some common terms found in imaging reports include:

Term in the report	What does it mean?
Lymph node	Refers to a lymph gland that is normally present in the body.
Reactive lymph node	Usually suggests changes associated with infection or an immune response.
Lymphadenopathy	Describes enlarged lymph nodes or lymph nodes showing abnormal characteristics.
Suspicious lymph node	A lymph node that may require further investigation because of its imaging characteristics.
FDG uptake	Indicates increased metabolic activity in a particular area on PET/CT imaging. It may also occur due to inflammatory conditions unrelated to cancer.

Does an Enlarged Lymph Node Always Mean Cancer?

An enlarged lymph node does not necessarily contain cancer cells. Similarly, a lymph node that appears normal in size may contain tumor cells detectable only under a microscope. Therefore, imaging findings are interpreted together with the patient’s symptoms, medical history, and any additional examinations considered necessary.

Lymph nodes may become enlarged due to infections, inflammatory diseases, and various immune responses. However, in certain cancers, tumor cells can reach the lymph nodes through lymphatic vessels. This is known as lymph node metastasis.

Why Are Lymph Nodes Important in Gynecologic Cancers?

Evaluating lymph nodes in gynecologic cancers can help determine the extent and stage of the disease. However, patterns of lymphatic spread differ depending on the type of cancer.

In endometrial (uterine) cancer, the status of pelvic and para-aortic lymph nodes may be important for cancer staging and planning additional treatment after surgery.
In cervical cancer, lymph node involvement may affect the stage of the disease and treatment options, such as surgery or chemoradiotherapy.
In ovarian cancer, the disease may spread to the peritoneum and other tissues, as well as to lymph nodes. These findings are important when assessing the extent of the disease.
In vulvar cancer, lymph nodes in the groin area are particularly important. Cancer spread to these nodes is one of the factors that may influence treatment planning.

Lymph node involvement may have different implications depending on the type of cancer and the location of the affected nodes. Therefore, it is not interpreted in the same way in every gynecologic cancer.

What Do Positive and Negative Lymph Nodes Mean in a Pathology Report?

Lymph nodes removed during cancer surgery or collected through a biopsy may be examined in a pathology laboratory. This examination aims to determine whether tumor cells are present within the lymph nodes.

The following terms may appear in a pathology report:

Negative lymph node: No cancer cells were detected in the examined lymph node.
Positive lymph node: Cancer cells were found in the examined lymph node.
Micrometastasis: A small focus of tumor cells within a lymph node, identified through microscopic examination.
Isolated tumor cells: A very small number of tumor cells or tiny clusters of tumor cells detected within a lymph node.

The significance of these findings for cancer staging and treatment varies according to the type of cancer. A negative result only indicates that no tumor cells were detected in the lymph nodes examined; it does not, by itself, prove that cancer is absent elsewhere in the body.

The pathology report is evaluated by considering how many lymph nodes were examined, how many contained tumor cells, and the characteristics of any involvement identified.

How Does Lymph Node Involvement Affect Treatment Planning?

The detection of cancer cells in lymph nodes may change the stage of certain gynecologic cancers. This information can help assess the risk of recurrence after treatment and guide decisions about additional therapies.

For example, radiotherapy, chemotherapy, or other systemic treatments may be considered for some patients with lymph node involvement. However, a positive lymph node result does not automatically mean that every patient will receive the same treatment.

Treatment decisions take into account the type and stage of cancer, pathological characteristics, molecular findings, and the patient’s overall health. Therefore, evaluating lymph node results from a gynecologic oncology perspective may be important in developing an appropriate treatment plan.

Are Lymph Nodes Removed in Every Patient With Gynecologic Cancer?

Surgical removal of lymph nodes is not necessary for every patient. The method used to evaluate lymph nodes depends on the type and stage of cancer, imaging findings, and individual patient characteristics.

In some patients, a sentinel lymph node biopsy may be performed. A sentinel lymph node is the lymph node to which tumor cells are most likely to spread first through the lymphatic system. In suitable patients, this approach may reduce the need for more extensive lymph node removal. In other situations, a more comprehensive examination of pelvic or para-aortic lymph nodes may be necessary.

For more information about surgical techniques and procedural details, you can read my article “What Is Pelvic and Para-Aortic Lymph Node Dissection and Why Is It Performed?“.

How Should Lymph Node Results Be Evaluated?

The significance of lymph node findings on imaging and pathology depends on the patient’s clinical condition and, when cancer is present, the type of cancer involved.

In patients diagnosed with gynecologic cancer, these findings help determine the extent of the disease and guide the selection of an appropriate treatment approach. Therefore, rather than focusing on a single term in a report, it is important to consider all findings together.

This content is intended for general informational purposes only. Lymph node findings should be evaluated individually for each patient by the treating physician.

What Are Lymph Nodes? Why Are They Important in Gynecologic Cancers?