Vulvar cancer Inguinal nodal exploration sentinel node or lymphadenectomy Dr Jérémie Zeitoun · Surgeon Paris 8th
When vulvar cancer is diagnosed, we need to know whether the groin nodes are involved. Two techniques exist — the sentinel lymph node, targeted and leg-sparing, and the full inguinofemoral lymphadenectomy, heavier but necessary in certain situations. Here is how the choice is made, at consultation and at the multidisciplinary meeting.
The inguinal sentinel lymph node in 7 key figures
Concrete and meaningful information about this technique that has transformed the surgical management of vulvar cancer over the past two decades.
The sentinel lymph node is the first node draining the tumour area — the one cancer cells would reach first if they were to spread. If it is analysed and contains no tumour cells, we know with high reliability that the downstream nodes are also free of disease. It then becomes unnecessary to remove all the groin nodes — a heavier procedure that exposes patients to chronic leg lymphoedema and sequelar pain.
This targeted approach — 1 to 3 nodes removed instead of 15 to 20 — has transformed vulvar cancer management over the past twenty years. Validated by the international GROINSS-V trials (over 1,500 patients), it provides the same prognostic information while preserving leg function. It is today the reference approach for eligible vulvar cancers.
The sentinel lymph node — how it is located and removed
Finding the sentinel node is the very art of this intervention. Several complementary techniques are used in combination to make sure we don't miss it — detection rate close to 100%. Here are the 4 stages, from pre-operative mapping to meticulous laboratory analysis.
1 — Pre-operative mapping (the day before)
Finding where the sentinel node hides before surgeryThe principle. Before operating, we need to know where to look. That is the role of lymphoscintigraphy: a nuclear medicine examination that shows, on images, the path taken by the lymph from the tumour to the groin.
How it works. The day before or the same morning of surgery, you go to nuclear medicine. We inject a small dose of weakly radioactive product (technetium-99m) around the tumour — a few quick injections, no more painful than a blood test. Then a camera takes images for 30 minutes to 2 hours.
What we see. The images show exactly which lymph node lights up first in the groin. That is the sentinel node. Sometimes only one, sometimes two or three, sometimes bilateral. These images are given to the surgeon — who therefore knows where to make the incision.
Rest assured about radioactivity. The injected dose is very low, comparable to a standard X-ray. It eliminates from your body in 24-48 hours. Compatible with a future pregnancy.
2 — Localisation in the operating theatre
Precisely locating the sentinel node during surgeryThe principle. Under general anaesthesia, we combine two or three techniques that confirm each other so as not to miss the sentinel node.
The gamma probe. A hand-held device that looks like a Geiger counter. We pass it over the groin skin — it "beeps" louder where the radioactive node is hidden. This is what guides the incision (2-3 cm).
Blue dye. At the start of surgery, we inject a little blue (isosulfan blue or methylene blue) around the tumour. It travels through the lymph and stains the vessel and sentinel node bright blue — visible to the naked eye once the incision is made.
Fluorescence (ICG). More recent: a fluorescent dye (indocyanine green) detected by an infrared camera. The node becomes luminous on a screen. Useful when we want to avoid the blue (allergies) or in addition to the isotope.
In practice: gamma probe + blue dye routinely. ICG as an option depending on the centre.
3 — The removal itself
1 to 3 nodes removed per groin, in 30 to 60 minutesThe incision. Small, horizontal, in the groin fold — generally 2 to 3 cm. Well hidden long-term in the natural fold. A single incision if the lesion is well lateralised to the right or left, two incisions if the lesion is midline.
The procedure. We follow the blue lymphatic vessel to the sentinel node, and remove it carefully. Then we check that there is no residual radioactivity in the operative bed (must be < 10% of that of the node). On average, 1 to 3 nodes per groin.
The closure. Absorbable sutures. Sometimes a small suction drain for a few days. Dressing.
The duration. 30 to 60 minutes per groin. Often performed at the same operative time as the vulvectomy, under the same anaesthesia — with no significant extension of hospitalisation.
4 — Laboratory analysis of the node
What the histopathological examination will determineOnce removed, the node is handed over to a specialist physician (pathologist) who will analyse it in detail. This analysis will guide the rest of the treatment.
The result usually comes within 7 to 15 days. A postoperative consultation is scheduled at D15 to explain it and decide together on the next steps.
Two possible situations:
• Disease-free node (negative): no cancer cells found. This is the most frequent situation. No further surgery on the groin is needed.
• Involved node (positive): cancer cells present. Depending on the quantity of cells found, two options will be discussed at the multidisciplinary meeting — either complementary inguinal lymphadenectomy, or targeted radiotherapy of the groin. The choice depends on your situation.
Everything will be explained clearly at consultation, with all the time needed. No decision is taken without you.
Full inguinal lymphadenectomy
Inguinal lymphadenectomy — more precisely inguinofemoral lymphadenectomy — consists of removing all the lymph nodes of one or both groins. It is the historical reference procedure before the arrival of the sentinel node. It remains essential in several situations.
When is lymphadenectomy necessary?
Situations where the sentinel node is not suitableFull inguinal lymphadenectomy is the preferred option in several well-defined situations:
• Preoperative suspicion of nodal involvement — i.e. inguinal nodes that are suspicious on clinical examination (palpable) or on imaging (ultrasound, MRI, sometimes PET-CT).
• Sentinel node detection failure intraoperatively — if the sentinel node cannot be located during surgery, full lymphadenectomy is performed for safety, to avoid missing any nodal disease.
• Positive sentinel node on analysis — depending on the quantity of tumour cells, either lymphadenectomy is completed, or targeted radiotherapy is chosen.
• Groin recurrence after initial treatment.
In cases where the sentinel node is not applicable from the outset (tumour over 4 cm, multifocal lesions), full lymphadenectomy is also proposed — but this is a different situation: the sentinel node was not attempted.
This decision is always made at the multidisciplinary team meeting, with a panel of specialists (surgeon, oncologist, radiotherapist, pathologist, radiologist) who review your case together.
How does lymphadenectomy take place?
The principle of the procedureThe incision. An incision in the groin fold, longer than for a sentinel node (8 to 12 cm). One or both groins depending on the location of the vulvar lesion.
The procedure. The entire lymph node and fatty tissue of the inguinofemoral region is removed methodically, respecting vessels and nerves. Usually 10 to 20 nodes are removed per groin.
The closure. Systematic suction drains, kept generally several days to several weeks, until the drained fluid becomes minimal. Careful sutures.
The duration. 1 to 2 hours per groin. Often performed in the same operative time as the vulvectomy, under the same general anaesthesia.
Hospital stay. 5 to 7 days on average, sometimes more depending on drains and healing.
Recovery from lymphadenectomy — more demanding
A reality to know before surgeryFull inguinal lymphadenectomy has heavier recovery than sentinel node. That is precisely why the sentinel node technique was developed — to avoid these complications when possible.
Most frequent complications after lymphadenectomy:
• Lymphocele (lymph pocket in the groin) — frequent, sometimes drained at the consultation.
• Wound infection and dehiscence — relatively frequent.
• Chronic leg lymphoedema (lasting swelling) — the most impactful late complication. Well managed today with specialised physiotherapy and compression.
• Sensory nerve damage (numb areas of the thigh), most often transient.
Complete recovery takes several months. Close follow-up is set up to identify complications quickly and treat them — at consultation or by teleconsultation.
With the advent of radiotherapy as an alternative to lymphadenectomy in cases of positive sentinel node with low tumour burden (GROINSS-V II study), we have today more options to spare the leg.
When sentinel node, when lymphadenectomy
Not all patients are eligible for the sentinel node. When you are, it is the first option because the leg is preserved. When you are not, it is not a drama — it simply means that full inguinal lymphadenectomy is the safest option in your situation.
The sentinel node is offered when
• The vulvar lesion is single and of limited size.
• The groin nodes appear normal on clinical examination and imaging (inguinal ultrasound, sometimes MRI or PET).
• The preoperative workup is overall reassuring.
Lymphadenectomy is offered when
• There is preoperative suspicion of nodal involvement — palpable nodes on examination or suspicious on imaging.
• In case of sentinel node detection failure intraoperatively.
• When a sentinel node is positive on analysis with significant tumour burden (depending on quantity, targeted radiotherapy may also be an option).
• In case of groin recurrence.
At consultation, I will explain in detail why a particular option is proposed, based on your personal situation. The decision is always shared — and always validated at the multidisciplinary meeting. If you have the slightest doubt, teleconsultation remains available throughout your care pathway.
Guidelines used (2025 update): FIGO 2025 (Olawaiye et al, Int J Gynecol Obstet 2025, global update) · NCCN Vulvar Cancer 2025 (v1.2025, US guidelines) · Restaino et al, Cancers 2025 (systematic comparison of international guidelines) · ESGO 2023 (Oonk MHM et al, Int J Gynecol Cancer 2023, European guidelines) · Saint-Paul-de-Vence 2024 (Selle & Narducci, Francophone guidelines) · GROINSS-V I (Van der Zee AGJ et al, J Clin Oncol 2008, n=403) and GROINSS-V II (Oonk MHM et al, Lancet Oncol 2021, n=1535).
A nodal procedure has been proposed to you?
Bring your biopsy reports, pelvic MRI, and MDT decision if available. The consultation lasts 30 minutes — a personalised plan is given to you with the proposed nodal procedure.
Step by step, the sentinel node pathway
From pre-operative lymphoscintigraphy to histopathology result, here is exactly how the procedure unfolds.
- 01
The day before — lymphoscintigraphy
Injection of a weakly radioactive tracer (technetium-99m) around the tumour. A few quick injections. Image acquisition in nuclear medicine (30 min to 2 h). Identification of the sentinel node(s).
- 02
Arrival in the operating theatre
Verification of identity, file, consent. Placement of an IV line. General anaesthesia, most often combined with epidural analgesia for postoperative comfort.
- 03
Blue dye injection
Peri-tumoural injection of blue dye (isosulfan blue or methylene blue) which will concentrate in the sentinel node. Sometimes replaced or supplemented by indocyanine green (ICG) detected by fluorescence.
- 04
Localisation and incision
Localisation of the node with the gamma probe (radioactivity counter). Small incision of 2 to 3 cm in the groin fold. One or two incisions depending on the laterality of the vulvar lesion.
- 05
Removal of 1 to 3 nodes
Identification of the blue and radioactive node, careful removal. Verification of the absence of residual radioactivity. Absorbable sutures, sometimes a small drain. Duration 30 to 60 minutes per groin.
- 06
Laboratory analysis
The node is handed to a specialist physician (pathologist). Detailed analysis within 7 to 15 days. Postoperative consultation at D15 to explain and decide on the next steps.
Recovery, complications and follow-up
Recovery after an isolated sentinel node is fast. When combined with a vulvectomy, the latter dictates the pace. Here are the figures and the main milestones.
The possible complications
The whole point of the sentinel node is to spare the leg. Let's honestly compare its complications to those of full inguinal lymphadenectomy: the difference is spectacular. All these complications, when they occur, are managed at the consultation or by teleconsultation. You stay in direct contact with me throughout this period.
| Complication | Sentinel node | Full dissection |
|---|---|---|
| Inguinal wound infection | 2 – 5 % | 15 – 30 % |
| Inguinal lymphocele (lymph pocket) | 5 – 10 % | 30 – 50 % |
| Seroma (fluid collection) | 5 – 10 % | 20 – 40 % |
| Chronic leg lymphoedema | 1 – 5 % | 20 – 40 % |
| Sensory nerve injury (thigh skin) | < 2 % | 10 – 20 % |
| Sentinel node detection failure | < 5 % | — |
References: Van der Zee AGJ et al, J Clin Oncol 2008 (GROINSS-V I, n=403) · Oonk MHM et al, Lancet Oncol 2021 (GROINSS-V II, n=1535) · Hinten F et al, Gynecol Oncol 2011 · Gaarenstroom KN et al, Int J Gynecol Cancer 2003.
The benefit is clear: between 5 and 10 times fewer complications with the sentinel node than with full dissection. Leg lymphoedema — that chronic disabling swelling — drops from 1 patient in 3 to 1 patient in 20-50. This is the real revolution of recent years in the treatment of vulvar cancer.
Recovery timeline
Recovery after an isolated sentinel node is fast — that is even one of its great advantages. When the sentinel node is combined with a vulvectomy, the latter dictates the pace. Here are the main milestones.
Hospital stay (often day case or 24h). Inguinal dressing. Analgesia. Early mobilisation.
Return home. Wound care. Walking allowed. Avoid heavy lifting.
Healing. D15 consultation with histopathology results. Return to sedentary work possible.
Gradual return to normal physical activity. Monitoring of leg for any swelling.
Sport, travel, swimming allowed. Scar faded. If complementary lymphadenectomy needed, it usually happens at this stage.
Clinical and ultrasound follow-up every 3-4 months for 2 years, then every 6 months until 5 years.
25 questions on the inguinal sentinel node
All the questions patients most often ask at consultation. If yours is not listed, ask it at our appointment — there is no stupid question.
What is a sentinel lymph node?
▾Why not a systematic lymphadenectomy?
▾Is the radioactive injection dangerous?
▾Is the injection painful?
▾What is the reliability of the technique?
▾What does the inguinal scar look like?
▾Will I be hospitalised for long?
▾And leg lymphoedema after sentinel node?
▾If the sentinel node is positive?
▾How does follow-up work afterwards?
▾What if the sentinel node is missed?
▾Will I avoid a second operation?
▾Do I need radiotherapy?
▾What is the risk of groin recurrence?
▾What are the GROINSS-V studies?
▾What are the contraindications?
▾Can I get a second opinion?
▾How many sentinel nodes does Dr Zeitoun perform per year?
▾Long-term follow-up: for how long?
▾Is the care covered at 100%?
▾Does my surgeon stay in contact between operations?
▾What to do in case of fever or unusual pain?
▾What anaesthesia for the sentinel node?
▾Will I have a urinary catheter?
▾Will I have psychological support?
▾Also read
Book an appointment
Has a sentinel lymph node biopsy been recommended? Bring your reports — consultation in 30 minutes with personalised plan.