How many lymph nodes in your groin

Inguinal lymph nodes are lymph nodes in the human groin. Located in the femoral triangle of the inguinal region, they are grouped into superficial and deep lymph nodes. The superficial have three divisions: the superomedial, superolateral, and inferior superficial.

Superficial inguinal lymph nodes[edit]

They are divided into three groups:

• inferior – inferior of the saphenous opening of the leg, receive drainage from lower legs
• superolateral – on the side of the saphenous opening, receive drainage from the side buttocks and the lower abdominal wall.
• superomedial – located at the middle of the saphenous opening, take drainage from the perineum and genitals.[1]

There are approximately ten superficial lymph nodes, and they drain to the deep inguinal lymph nodes. Inguinal lymph nodes may normally be up to 2 cm in size.[2]

They receive lymphatic afferents from the following:

Deep inguinal lymph nodes[edit]

There can be three, four or five deep inguinal lymph nodes. They lie medial to the femoral vein under the cribriform fascia. The uppermost node is in the groin, under the inguinal ligament, and is called Cloquet's node (also Rosenmuller's node).[3] This node is named for French surgeon Jules Germain Cloquet,[4][5] or for German anatomist Johann Christian Rosenmüller.[6][7] It can also be considered as the lowest of the external iliac lymph nodes.[8][citation needed] Cloquet's node is also considered as a potential sentinel lymph node.[3][9]

The deep inguinal lymph nodes drain superiorly to the external iliac lymph nodes, then to the pelvic lymph nodes and on to the paraaortic lymph nodes.[10]

Lymph node size[edit]

The mean size of an inguinal lymph node, as measured over the short-axis, is approximately 5.4 mm (range 2.1-13.6 mm), with two standard deviations above the mean being 8.8 mm.[11] A size of up to 10 mm is generally regarded as a cut-off value for normal vs abnormal inguinal lymph node size.[12]

Clinical significance[edit]

The presence of swollen inguinal lymph nodes is an important clinical sign because lymphadenopathy (swelling) may indicate an infection, or spread as a metastasis from cancers, such as anal cancer and vulvar cancer. Inguinal lymph nodes may normally be up to 2 cm.[2] The cut-off value for normal sized inguinal nodes is up to 10 mm.[12]

An inguinal lymph node dissection (also known as a groin lymph node dissection) is the removal of lymph nodes and all tissue from the groin region that may contain tumors.

The human body contains lymph nodes in the neck, armpits, and inguinal region. Lymph nodes found in the groin are called inguinal nodes.

Melanoma can spread to the inguinal lymph nodes. If the nodes are enlarged and felt by yourself or your physician, or if nodes are found to harbor melanoma after a sentinel lymph node biopsy. 

If melanoma is found in a lymph node in this region, a lymph node dissection, or clearance within the groin, is recommended, with the goal of controlling the progression or return of the cancer. In general, if a patient is found to have melanoma within any lymph nodes, the recommended course of action is to remove them surgically.  You will see physical therapy prior to surgery in our preoperative lymphedema clinic and be instructed on exercises and measured for a compression garment.

Minimally Invasive Inguinal Lymph Node Dissection (MILND)

Fox Chase Cancer Center is one of only a few centers in the country that offers a minimally invasive approach to inguinal lymph node dissection.  This approach allows the procedure to be done through three small incisions, rather than a larger incision.  The incisions are lower in the leg, away from the groin crease with the hope of decreasing the risk of infection, postoperative complications, and less pain. The procedure takes about 1.5 hours to perform. 

What to Expect During a Lymph Node Groin Dissection

Before the surgery, your anesthesiologist will give you general anesthetic, so you will not be awake during the procedure. Once you are asleep, local anesthetic is injected into the area, to provide additional comfort after the procedure, which generally lasts 1-3 hours. During the operation, your surgeon will make an incision in the groin.  Staples or stitches are used to close the incision.

The intention of the operation is to remove all of the lymph nodes and associated tissue without causing damage to any nearby arteries, veins, and nerves. However, minor groin nerves exist that must be removed during the operation, which results in mild numbness in the upper thigh that is often permanent.

Sometimes, removal of the lymph nodes around the groin area, into the pelvis, is necessary. In order to do so a larger incision extending up toward the abdomen must be made. The muscles of the abdominal wall are opened for full visibility of the lymph nodes; this area is then repaired before closure of the surface wound.

Because any large wound produces fluid, a surgical drain (typically a soft, flexible silicone tube) is placed to collect the fluid. Homecare nurses will be arranged to check the drain and incision. You can expect the drain to remain in place for 3-4 weeks following the procedure.

Preparing for the Procedure

In addition to normal preparations for your surgery, you will also need to wear special stockings to prevent blood clots in the legs. Typically, an injection of heparin or clexane into the abdominal skin is performed to reduce the risk of blood clots.

After the Procedure

Your physician will keep you on bed rest 4-6 hours following surgery. You will likely stay in the hospital 1 or 2 nights and go home with the drain. Nursing staff will train you in the proper care and arrange for follow up before returning home. At the time of discharge, you will likely receive a prescription for pain medication. 

After 2-3 weeks, the stitches and/or staples will be removed. The scar in the groin will fade over time.

As with any surgical procedure, you will likely feel tired for a few weeks, and you should take a leave of 3-6 weeks from work to rest and heal. You should drive and resume normal activities once you feel fully in control again. Most patients do recover well from the procedure and resume all regular activities within 4-6 weeks.

After surgery, a pathologist will review and test the tissue that was removed from the groin. This detailed examination takes about 7-10 working days. The results will determine your follow-up care and whether further treatment is necessary.

Regular post-operative checks are recommended to check the healing progression and look for any signs of a possible melanoma recurrence. The surgery taken place will help to prevent the melanoma from progression in the groin area. However, because the melanoma could spread to other regions within the body, ongoing, regular follow up is recommended.

Possible Side Effects

Most patients recover from the surgery well without any major issues. Some common side effects, however, may include fluid collection in the groin and minor wound infection. These problems are simple to manage and do not typically require readmission to the hospital.  The most common side effect is lymphedema and this occurs in approximately 20% of patients.  If it occurs it can be months or years after the procedure. 

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