Are There Lymph Nodes in Your Buttocks?

There are lymph nodes in and around the buttocks, though they are not as well known as the clusters you can feel in your neck, armpits, or groin. The gluteal region contains both deep nodes nestled alongside major blood vessels and, in some people, smaller nodes in the fat-filled spaces near the anus. What makes this area confusing is that the skin of the buttocks mostly drains its lymph fluid to the groin rather than to nodes within the buttock itself, so a buttock infection often shows up as a swollen lump in your groin instead. The anatomy here is genuinely layered, and understanding it matters for everything from diagnosing a mysterious lump to tracking how cancers spread.

Where the Gluteal Lymph Nodes Sit

The lymph nodes in the buttock region belong to the parietal group of the internal iliac nodes. They are divided into two sets: superior gluteal lymph nodes and inferior gluteal lymph nodes. Both sit alongside the blood vessels that share their name, deep within the muscular tissue of the pelvis and buttock. They collect lymph from the deeper structures of the pelvis, including the gluteal muscles beneath their tough fascial covering and some of the pelvic organs. From there, the fluid flows onward into the internal and common iliac nodes and eventually reaches the lumbar nodes alongside the spine.¹

There is also a separate group of nodes in the ischioanal fossa, which is the fat-filled space that sits on either side of the anal canal, deep between the pelvic floor muscles and the skin of the lower buttock. These ischioanal nodes are small and rarely discussed in textbooks, but MRI studies have identified them becoming enlarged in people with conditions like perianal fistulas and Crohn’s disease.²

Because these nodes are buried deep, you cannot feel them by pressing on the surface of your buttock the way you might feel a swollen node in your neck. They are typically discovered on imaging, which is one reason the gluteal lymph nodes get far less attention in everyday medicine than their superficial counterparts.

Why a Buttock Problem Often Swells Your Groin

If the buttocks have their own lymph nodes, why does a skin infection on your rear end cause a lump in your groin? The answer lies in the difference between the skin’s drainage and the deep tissue’s drainage. The skin and subcutaneous fat of the buttock drain predominantly to the superficial inguinal lymph nodes, the chain of nodes that runs along the crease of your groin. A radiological anatomy study mapping pelvic lymph drainage found that the medial gluteal skin drains to one group of inguinal nodes while the lateral gluteal skin drains to a different group in the same inguinal chain.³

The inguinal lymph nodes essentially act as a drainage crossroads for the lower trunk, genitals, perineum, and lower extremities.⁴ So when a boil, abscess, insect bite, or cut on the buttock triggers an immune response, the lymph fluid carrying immune cells and debris travels down toward the groin, and those are the nodes that swell up. Most people interpret that groin lump as completely unrelated to whatever happened on their buttock, but the two are directly connected by the lymphatic plumbing.

The deep gluteal structures, on the other hand, send their lymph in a different direction entirely. The muscles, bones, and deeper pelvic tissues drain into the internal iliac system and then upward toward the spine. This means that a deep-seated problem like a pelvic tumor could enlarge the gluteal lymph nodes themselves without producing any swelling in the groin at all.

Conditions That Enlarge the Gluteal Lymph Nodes

Because the deep gluteal nodes are hidden from physical examination, doctors typically find them enlarged incidentally on MRI or CT scans done for other reasons. An MRI-based study using high-resolution 3.0 Tesla imaging identified 16 cases of enlarged inferior gluteal lymph nodes and cataloged the conditions responsible. The most common cause was perianal fistula, accounting for seven of the cases across both the inferior gluteal and ischioanal node groups. Other causes included pressure ulcers, non-Hodgkin lymphoma, cancers of the prostate, endometrium, and anus, and a presacral abscess.²

The pattern is telling. Inflammatory conditions, especially those involving chronic fistulas and Crohn’s disease, were the leading culprits. Cancers came in second, and these were typically advanced malignancies that had spread from nearby organs. In one documented case of metastatic prostate cancer, both the left and right inferior gluteal lymph nodes were involved simultaneously, detected only because of specialized imaging.¹

None of these patients walked in complaining of a “swollen lymph node in the buttock.” The enlarged nodes were found because imaging was being done to investigate something else. This is an important point for anyone worrying about a lump they can feel in their buttock: a palpable lump there is far more likely to be a cyst, abscess, lipoma, or other soft-tissue mass than a swollen lymph node.

Infections and Injections That Trace Back to the Buttocks

A practical scenario that catches people off guard is when a minor infection on the buttock triggers noticeable lymph node swelling somewhere else. Tick bites are a good example. In one documented case, a patient developed a painful bite on the left buttock from a tick, followed within weeks by a skin ulcer at the bite site and significant swelling of the left inguinal lymph nodes. The inguinal swelling was a direct result of the immune response traveling along the lymphatic pathway from the buttock skin to the groin.⁵

Intramuscular injections in the gluteal region can also produce unexpected lymph node reactions, though these occur not in the buttock itself but downstream in the inguinal chain. One case involved a patient who had received repeated gluteal intramuscular injections and later developed lipid-filled granulomas in an inguinal lymph node. The exogenous lipid material from the injection site had followed the lymphatic drainage pathway from the buttock muscle into the groin node, where it triggered a foreign-body reaction.⁶ This is unusual, but it illustrates how the lymphatic system can carry material from the gluteal region to distant node stations.

Cancer Staging and Sentinel Node Mapping

The lymphatic drainage of the buttocks becomes critically important when a cancer develops in or near the region. With melanoma, for instance, surgeons use a technique called sentinel lymph node mapping to determine where a tumor’s lymph fluid drains first, because the first node in the chain is the most likely place cancer cells will land if they spread. A study of over 300 patients with melanomas on the lower extremity or buttocks tracked sentinel node drainage patterns as part of treatment planning.⁷ For buttock melanomas, the sentinel node can turn up in the groin, in the pelvis, or occasionally in both, depending on the tumor’s exact position relative to the skin’s lymphatic watershed lines.

The concept of a lymphatic watershed is worth understanding here. The buttock sits at a crossroads where lymph drainage divides between the groin and the pelvic nodes. A study mapping the collecting lymphatic vessels of the hip in cancer survivors found multiple drainage pathways running from the hip region, with posterolateral pathways predominating in some areas and posteromedial or anteromedial pathways in others.⁸ This variability means that a melanoma on the upper buttock might drain to a completely different node basin than one on the lower buttock. Surgeons cannot assume where cancer will go based on the tumor’s location alone, which is why imaging and dye-tracing techniques are standard.

Sarcomas and other deep-tissue tumors in the buttock can also spread to regional lymph nodes. In one reported case of synovial sarcoma of the buttock, MRI revealed a large mass with regional lymph node involvement.⁹ And when radiologists evaluate any soft-tissue buttock tumor, lymph node involvement is considered one of the key features to assess.¹⁰

Gluteal Lymphedema

When lymph nodes in the pelvis or groin are removed during cancer surgery or damaged by radiation, the fluid they normally process can back up. Most people associate this outcome with arm or leg swelling, but the buttock can be affected too. A study using indocyanine green lymphography and MRI identified gluteal lymphedema in a subset of patients with lower-extremity lymphedema. Those patients had a higher incidence of skin thickening in the gluteal region and showed roughly a 20% increase in subcutaneous tissue on the affected side, compared with about 11% on the unaffected side.¹¹

Gluteal lymphedema is underdiagnosed partly because people expect lymphedema to show up as a swollen limb, not as one buttock gradually getting larger or feeling heavier than the other. It tends to occur alongside leg lymphedema in patients who have had pelvic lymph node dissection, commonly for gynecological, urological, or colorectal cancers. If you notice persistent swelling or a feeling of tightness in one buttock after pelvic cancer treatment, it is worth raising with your care team rather than assuming it is just weight gain or inactivity.

When Chronic Skin Conditions Create Their Own Lymph Tissue

Hidradenitis suppurativa is a chronic inflammatory skin condition that commonly affects the buttocks, groin, and underarms. It causes painful boils and tunneling wounds under the skin, and researchers have recently discovered that in severe cases, the affected skin forms its own miniature immune structures that behave somewhat like lymph nodes. A study examining skin tissue from hidradenitis patients identified organized clusters of immune cells called tertiary lymphoid structures forming within the lesional skin itself. These structures were driven by a significant increase in specialized fibroblasts that produce immune-attracting signals.¹²

These are not true lymph nodes, but they are functionally analogous: organized immune tissue that can sustain a chronic inflammatory response. Their discovery helps explain why hidradenitis suppurativa in the buttocks is so persistent and difficult to treat. The disease essentially builds its own inflammation-sustaining infrastructure inside the skin. For patients, the practical takeaway is that those deep, hard lumps around hidradenitis flares are not conventional swollen lymph nodes but locally generated immune structures, which is why antibiotics alone often fail to resolve them.

What a Lump in Your Buttock Probably Is

Given that the actual gluteal lymph nodes are too deep to feel through the skin, a palpable lump in the buttock is almost never a swollen lymph node. The far more common explanations include:

Lipomas: Benign fatty growths that are soft, movable, and painless. They are among the most common soft-tissue lumps anywhere on the body.
Epidermoid cysts: Firm, round lumps just under the skin caused by a plugged hair follicle or minor skin trauma. They can become inflamed and painful if they rupture.
Abscesses: Painful, red, warm collections of pus caused by bacterial infection. Gluteal abscesses can follow minor skin breaks, ingrown hairs, or even injections.
Pilonidal cysts: These form near the top of the buttock crease and are especially common in younger adults with more body hair.
Hematomas: Blood collections from trauma or injury to the gluteal muscles.

Soft-tissue tumors, both benign and malignant, can also occur in the buttock. Radiologists evaluating buttock masses look at features like size, borders, internal composition, and whether nearby lymph nodes appear involved to distinguish harmless lumps from ones requiring biopsy.¹⁰ A lump that is growing, firm, painless, and deep deserves imaging. A lump that is tender, red, and appeared over a few days is more consistent with infection.

Checking the Right Nodes When Something Is Wrong

If you are concerned about an infection, bite, or wound on the skin of your buttock, the place to check for reactive lymph node swelling is your groin, not your buttock. The superficial inguinal nodes sit in the crease between your thigh and lower abdomen and are normally pea-sized or smaller. When they swell in response to a buttock skin problem, they may become grape-sized and tender. This is generally a normal immune response and resolves once the underlying problem clears.

If you are dealing with a deeper issue, like symptoms of a perianal fistula, unexplained pelvic pain, or changes related to a known cancer, the relevant nodes are the deep gluteal and internal iliac nodes that only imaging can evaluate. In these situations, your doctor will typically order an MRI or CT scan rather than relying on physical examination. The inferior gluteal and ischioanal nodes that show up on these scans can provide important diagnostic clues about pelvic infections, inflammatory bowel disease, and cancer spread that would otherwise be invisible to both patient and clinician.²

1
PubMed Central. Concomitant Bilateral Inferior Gluteal Lymph Node Involvement in Metastatic Prostate Adenocarcinoma Detected on 68 Gallium-Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography
2
PubMed Central. Use of MRI to identify enlarged inferior gluteal and ischioanal lymph nodes and associated findings related to the primary disease
3
Radiotherapy and Oncology. Anatomical bases for the radiological delineation of lymph node areas. Part III: Pelvis and lower limbs
4
The American Surgeon. The Surgical Anatomy of the Inguinal Lymphatics
5
Advances in Dermatology and Allergology. Skin ulceration and inguinal lymphadenopathy as a symptom of a rare tick-borne disease
6
Indian Journal of Pathology and Microbiology. Lipid lymphadenopathy
7
Melanoma Research. Prognostic significance of drainage to pelvic nodes at sentinel lymph node mapping in patients with extremity melanoma
8
PubMed Central. Watershed of Collecting Lymphatic Vessels of The Hip; Between Back and Thigh
9
PubMed Central. Synovial sarcoma of the buttocks presenting with a non-healing wound and rapid progression after local resection: a case report
10
Clinical Radiology. Tail-end troubles: Imaging of soft-tissue buttock tumours
11
Journal of Plastic, Reconstructive & Aesthetic Surgery. Gluteal lymphoedema associated with lower extremity lymphoedema: A preliminary study with indocyanine green lymphography and magnetic resonance imaging
12
Immunity. Tertiary lymphoid structures maintain chronic inflammation in hidradenitis suppurativa