Groin Lymph Node Staging in Penile Cancer
Penile cancer most commonly spreads first to the lymph nodes in the groin. Importantly, lymph-node spread can sometimes be present even when the groins feel completely normal.
The correct lymph-node pathway depends on the pathology of the penile tumour and whether the groin nodes are clinically normal, suspicious or confirmed to contain cancer.
Why do the groin lymph nodes matter?
Penile cancer generally follows a predictable lymphatic pathway. Cancer cells can move from the penis to lymph nodes in one or both groins before progressing to pelvic lymph nodes or more distant sites.
This means there are two separate questions after a penile cancer diagnosis:
- How should the tumour on the penis be treated?
- Is there evidence that cancer has reached the lymph nodes?
A relatively small penile tumour can sometimes have pathological features associated with meaningful lymph-node risk.
Glans resurfacing, glansectomy or another penile-preserving operation may successfully treat the primary tumour while a separate groin-staging pathway is still required.
The usual lymphatic pathway
Penile lymphatic drainage generally progresses through the inguinal nodes before reaching the pelvic lymph nodes.
What does clinically node-negative — cN0 — mean?
cN0 means no enlarged or suspicious groin lymph nodes are identified on clinical examination.
No suspicious nodes can be felt
This is reassuring, but it does not prove that the groin nodes are free of cancer.
Current guideline data suggest approximately 20–25% of men with clinically node-negative penile cancer can still harbour occult microscopic nodal metastases.
One or more nodes are suspicious
A palpable, enlarged or otherwise suspicious groin node requires a different pathway.
Imaging and image-guided tissue sampling are usually used to determine whether the node represents metastatic penile cancer.
The decision to perform invasive lymph-node staging is therefore driven primarily by the pathological risk of the penile tumour.
Who needs invasive groin lymph-node staging?
The risk of microscopic lymph-node spread is estimated using the final pathology of the primary penile tumour.
Selected low-risk disease
Superficial or favourable low-risk tumours may be suitable for groin surveillance rather than immediate invasive nodal staging.
The exact pathway depends on the final pathological stage and grade.
Selected T1a disease
Some patients fall into an intermediate area where surgical staging versus surveillance needs to be considered individually.
Age, frailty, pathology and ability to comply with strict follow-up can influence this discussion.
T1b or higher
Current EAU guidance recommends surgical lymph-node staging when the groins are clinically negative but the primary tumour is T1b or higher.
Dynamic sentinel node biopsy is the preferred staging technique when appropriate specialist expertise is available.
What is a sentinel lymph node?
A sentinel lymph node is one of the first lymph nodes reached by lymphatic drainage from the penile tumour.
Dynamic sentinel node biopsy — often abbreviated DSNB — aims to identify and remove these first-draining nodes rather than removing all groin lymph nodes solely for staging.
If the sentinel nodes contain no cancer, a larger lymph-node dissection can often be avoided.
If metastatic cancer is identified, further therapeutic treatment of that groin is generally required.
How does dynamic sentinel node biopsy work?
Ultrasound the groins
When DSNB is planned, groin ultrasound is generally performed first.
If a lymph node looks suspicious on ultrasound, fine-needle aspiration can be performed to check for cancer cells.
Map the lymphatic drainage
A tracer is used to identify the lymphatic pathways draining from the penile tumour region toward the first groin nodes.
Additional imaging such as SPECT/CT may form part of mapping in specialist centres.
Remove the sentinel nodes
Small groin incisions are used to identify and remove the mapped sentinel nodes.
The purpose is accurate staging with less disruption of normal lymphatic tissue than a full dissection.
Review the pathology
The removed nodes are examined carefully for metastatic penile cancer.
A positive sentinel node generally leads to completion inguinal lymph-node treatment on that side.
Sentinel node biopsy is not the same as inguinal lymph-node dissection
These procedures have different roles in the penile cancer pathway.
Dynamic Sentinel Node Biopsy
Primarily used to look for occult microscopic disease in selected men whose groins are clinically normal.
- targets first-draining nodes
- smaller operation
- aims to reduce unnecessary extensive groin surgery
Inguinal Node Dissection in cN0 Disease
If DSNB is unavailable, referral is not feasible or another surgical approach is selected, an inguinal lymph-node dissection may be used for staging.
This generally carries greater morbidity than DSNB.
Inguinal Lymphadenectomy for Confirmed Disease
When metastatic inguinal disease is confirmed, lymph-node surgery becomes a cancer-treatment procedure rather than simply a staging procedure.
What if a groin lymph node can already be felt?
A palpable groin node does not automatically prove metastatic cancer.
Enlarged nodes can occasionally occur because of infection or inflammation, particularly when an ulcerated penile tumour is present.
However, suspicious nodes in a patient with penile cancer should be investigated promptly.
Assessment can include:
- groin ultrasound
- image-guided fine-needle aspiration or core biopsy
- cross-sectional staging imaging
- review of the primary penile tumour pathology
What do cN1, cN2 and cN3 mean?
Single mobile unilateral node
A suspicious mobile node is present in one groin.
Confirmed metastatic disease generally requires therapeutic treatment of that inguinal nodal basin.
Multiple or bilateral mobile nodes
More than one mobile inguinal node or involvement on both sides represents a greater regional disease burden.
Surgery, systemic therapy and sequencing require individualised planning.
Fixed groin mass or pelvic adenopathy
Fixed bulky inguinal disease or clinically evident pelvic nodes represents advanced regional nodal disease.
Multimodal treatment, commonly involving systemic therapy before consolidative surgery in suitable patients, is generally considered.
Inguinal lymph-node dissection
Inguinal lymph-node dissection — ILND — removes lymphatic tissue from the groin and is an important treatment when regional metastatic penile cancer is confirmed.
Fascial-sparing or radical dissection
In selected cN1 disease, current guidance allows either an ipsilateral fascial-sparing dissection or open radical inguinal lymph-node dissection.
The chosen template depends on the clinical situation and specialist surgical assessment.
Radical inguinal lymph-node dissection
Open radical ILND remains the standard surgical treatment for selected patients with more extensive mobile inguinal nodal disease.
The aim is complete regional cancer control while attempting to reduce lymphatic and wound complications where possible.
What are the risks of inguinal lymph-node surgery?
Groin lymph-node surgery can be highly important for cancer control, but more extensive dissections carry meaningful morbidity.
Wound problems
Infection, wound breakdown, delayed healing and areas of skin necrosis can occur after larger groin dissections.
Lymphocele & seroma
Lymphatic fluid can collect beneath the wound and may occasionally require drainage or prolonged management.
Leg or genital lymphoedema
Removing lymphatic tissue can impair normal drainage from the leg, groin and genital region.
Bleeding or vascular injury
Groin surgery occurs near major blood vessels and therefore carries recognised bleeding and vascular risks.
Thrombosis
Major cancer surgery and reduced mobility can contribute to venous thromboembolic risk.
Further treatment
Final lymph-node pathology may indicate a need for pelvic surgery, radiotherapy, systemic therapy or multidisciplinary treatment.
When do the pelvic lymph nodes become important?
Pelvic lymph-node involvement generally develops after metastatic disease has reached the inguinal nodes on the same side.
The likelihood increases when inguinal lymph-node pathology shows a greater volume of disease or more aggressive nodal features.
Features associated with increased pelvic-node risk include:
- multiple positive inguinal lymph nodes
- three or more involved nodes on one side
- extranodal extension
- clinically evident pelvic lymphadenopathy
What if the groin disease is already extensive?
A fixed groin mass, extranodal extension or clinically evident pelvic lymph-node disease represents a different situation from microscopic or low-volume nodal metastasis.
Upfront major surgery is not always the preferred first step.
In suitable patients, treatment may involve:
- complete CT or PET/CT staging
- multidisciplinary cancer review
- cisplatin- and taxane-based systemic therapy where appropriate
- assessment of response
- consolidative inguinal and pelvic surgery when feasible
- radiotherapy or chemoradiotherapy in selected circumstances
From penile pathology to groin treatment
Establish the penile cancer pathology
Tumour stage, grade and other pathological features help estimate the risk of lymph-node metastasis.
Examine both groins
The groins are assessed for palpable or otherwise suspicious lymph nodes.
Choose cN0 staging or cN+ investigation
High-risk normal groins may undergo sentinel-node staging, while suspicious nodes require targeted assessment and tissue confirmation.
Review nodal pathology
Negative staging can support surveillance. Positive nodal pathology determines the need for completion or therapeutic lymph-node surgery.
Assess pelvic-node risk
The number of involved nodes, extranodal extension and imaging findings help determine whether pelvic treatment should be considered.
Long-term surveillance
Follow-up is tailored to the primary tumour, nodal pathology and any inguinal, pelvic or systemic treatment received.
What happens after lymph-node staging?
Follow-up depends on whether the groins were observed, surgically staged or found to contain metastatic disease.
Surveillance may include:
- regular examination of both groins
- self-examination where appropriate
- groin ultrasound in selected situations
- cross-sectional imaging for node-positive disease
- surveillance of the treated penis
- monitoring for lymphoedema or wound complications
Dr Jack Crozier
Dr Jack Crozier is a Brisbane urologist with advanced fellowship experience in uro-oncology, andrology and reconstructive urology.
His practice includes assessment of penile cancer, primary tumour surgery, penile-preserving and reconstructive considerations, and coordination of appropriate regional lymph-node staging and multidisciplinary cancer pathways.
Seeking review of your penile cancer staging plan?
Patients with an established diagnosis can provide existing pathology and imaging before major travel arrangements are made where appropriate.
Particularly useful records include:
- primary penile tumour pathology
- previous operation reports
- groin ultrasound reports
- FNA or lymph-node biopsy pathology
- CT, MRI or PET/CT reports and images
- oncology correspondence
Further examination, imaging or specialist nodal procedures may still be required before a definitive treatment plan can be confirmed.
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Penile cancer lymph-node FAQs
Why are the groin lymph nodes checked in penile cancer?
Penile cancer most commonly spreads first to lymph nodes in the groin. The presence and extent of lymph-node metastasis is therefore an important part of staging and treatment planning.
If my groin lymph nodes feel normal, can cancer still be present?
Yes. Microscopic metastases can be present in lymph nodes that are not enlarged or abnormal on examination. Current guideline data suggest occult nodal metastases may be present in approximately 20–25% of clinically node-negative patients overall.
What does cN0 mean?
cN0 means no palpable or otherwise clinically suspicious inguinal lymph nodes are identified during examination.
Does everyone with penile cancer need lymph-node surgery?
No. The need for invasive staging depends primarily on the risk features of the primary penile tumour and whether the groins are clinically normal or suspicious.
Which patients with normal groins need surgical staging?
Current EAU guidance recommends surgical lymph-node staging for clinically node-negative patients with high-risk primary disease, defined as T1b or higher. Selected T1a G2 patients require a more individualised discussion.
What is dynamic sentinel node biopsy?
Dynamic sentinel node biopsy maps and removes the first lymph nodes draining the penile tumour region. These nodes are examined for microscopic cancer in order to stage the groins while limiting unnecessary extensive lymph-node surgery.
Is sentinel node biopsy the same as a full groin dissection?
No. Sentinel node biopsy targets selected first-draining nodes for staging. Inguinal lymph-node dissection removes a much larger field of lymphatic tissue and may be used for therapeutic treatment when metastatic disease is confirmed.
What happens if the sentinel node contains cancer?
A positive sentinel node generally means further therapeutic treatment of the affected inguinal nodal basin is required, commonly with completion inguinal lymph-node dissection.
Can a CT or PET scan replace sentinel node biopsy?
Not reliably in a clinically node-negative groin. CT, MRI, PET and ultrasound are limited in their ability to detect small microscopic lymph-node metastases.
Why is ultrasound performed before sentinel node biopsy?
Ultrasound can identify nodes that look suspicious despite a normal clinical examination. These can undergo fine-needle aspiration before sentinel-node surgery.
What if I can already feel a lump in my groin?
A palpable or suspicious groin node should be assessed promptly. Image-guided biopsy is generally used to confirm metastatic disease before treatment when clinically appropriate.
Can an enlarged groin node just be infection?
Yes. Inflammation and infection can enlarge lymph nodes, especially when a penile lesion is ulcerated or infected. However, enlarged nodes in someone with penile cancer need appropriate investigation rather than assuming infection.
What is an inguinal lymph-node dissection?
Inguinal lymph-node dissection is surgery to remove lymphatic tissue from the groin. It can be used for staging in selected situations and is an important therapeutic treatment when metastatic inguinal penile cancer is confirmed.
What are the risks of groin lymph-node surgery?
Risks include wound infection, wound breakdown, lymphocele, seroma, leg or genital lymphoedema, bleeding, thrombosis and the possible need for further treatment. Risk varies considerably according to the extent of surgery.
When are pelvic lymph nodes removed?
Pelvic lymph-node treatment is considered when inguinal pathology shows a substantial risk of pelvic spread or when pelvic nodal disease is visible on imaging. Multiple positive inguinal nodes and extranodal extension are important risk features.
Can penile cancer spread directly to the pelvic lymph nodes?
The usual pathway is from the penis to the inguinal nodes and then to the pelvic nodes on that side. Isolated pelvic nodal spread without ipsilateral inguinal involvement is not the typical pattern.
What does extranodal extension mean?
Extranodal extension means cancer has grown through the outer capsule of a lymph node into surrounding tissue. It represents a higher-risk pathological feature and can alter pelvic and multidisciplinary treatment planning.
What happens if there are fixed or bulky groin nodes?
Fixed bulky groin disease or pelvic lymphadenopathy is considered advanced regional disease. Systemic treatment before surgery is often considered in suitable patients, followed by consolidative lymph-node surgery when feasible.
Does penile-preserving surgery mean the lymph nodes are low risk?
No. The amount of penile tissue removed and the risk of lymph-node spread are related to the tumour but are not the same issue. Lymph-node risk is determined from pathological features of the tumour.
Can I be assessed if I live interstate or overseas?
Potentially. Primary tumour pathology, previous operation reports, groin imaging, lymph-node biopsy results and staging scans can be reviewed as part of preliminary planning. Further in-person assessment or specialist nodal procedures may still be required.
Have you been diagnosed with penile cancer and are unsure what should happen with your groin lymph nodes?
Specialist review can help clarify the primary tumour pathology, risk of microscopic nodal spread and whether surveillance, dynamic sentinel node biopsy, inguinal lymph-node surgery or a more advanced regional treatment pathway should be considered.
Medical information disclaimer: This page provides general educational information and does not replace individual medical advice, diagnosis, multidisciplinary cancer review or informed consent. Lymph-node management in penile cancer depends on the primary tumour pathology, clinical groin findings, imaging, lymph-node pathology, previous treatment, general health and individual circumstances. Dynamic sentinel node biopsy and inguinal or pelvic lymph-node surgery are specialist procedures and may not be appropriate or available in every situation. Lymph-node surgery carries potential risks including wound complications, lymphocele, lymphoedema, infection, bleeding and thrombosis. Individual cancer outcomes cannot be guaranteed.