Inguinal lymph node dissection in penile cancer

Cancer of the penis is rare, with an incidence of 1 in 100,000 in the US. In 2025, 2190 new penile cancer cases will be diagnosed (less than 1% of all cancers in the US). Despite the disease's rarity, however, the mortality rate of penile cancer is high (510 deaths in 2025 in the US), likely due to a delay in presentation resulting in nonlocalized disease.¹ Approximately one-third of cases will have metastases to the inguinal lymph nodes at the time of diagnosis, and up to 25% of those with nonpalpable lymph nodes will harbor micrometastatic disease.²

Indications for Inguinal Lymph Node Dissection

Inguinal lymph node dissection (ILND) is indicated for patients with intermediate-or high-risk penile cancer (pathological stage T1b/T2 or higher disease), nonpalpable nodes, and no radiographic evidence of nodal involvement. For palpable lymph nodes, the decision to perform ILND is guided by the size, mobility, and biopsy results of the palpable and/or radiographically positive lymph nodes. For patients with a low-risk primary lesion and a unilateral, mobile lymph node less than 4 cm that is positive on biopsy, ILND is the standard treatment. In cases of a high-risk primary lesion or larger, fixed lymph nodes, multimodal management with neoadjuvant chemotherapy is generally recommended. Following a positive response to chemotherapy, the patient then undergoes ILND. The procedure is also considered for patients with enlarged pelvic lymph nodes, sometimes as part of a more extensive dissection that includes removing the pelvic lymph nodes. This multistep approach ensures that patients receive the most effective and least invasive treatment possible, tailored to their specific disease progression and risk factors.³

Description of ILND

The patient is brought to the operating theater, where general anesthesia is induced. The patient is placed in a supine position with legs in a frog leg position, and the feet are brought together and taped. Next, flaps are delineated by first drawing a line from the anterior superior iliac spine (ASIS) to the pubic tubercle. A 20-cm and 15-cm vertical marking is then made laterally and medially, respectively. The bottom lines are then connected horizontally.

A horizontal incision is then made 1 cm below the inguinal crease. Using electrocautery, the subcutaneous tissue is divided down to the Scarpa fascia. Once the fascia is visualized, skin hooks are placed, and flaps are created using either sharp dissection or electrocautery. Flaps should extend to the previously made skin markings. It is important to intermittently check the thickness of the flaps to ensure they are not too thin. Once the flaps are created, a pediatric Bookwalter Retractor is placed with moist laparotomy pads between the blades and skin, and not too much traction so as not to injure the flaps.

If a bilateral ILND is being performed for a unilateral clinically positive node(s), it is recommended to start with the clinically negative side so that the superficial nodes can be sent for frozen pathological analysis while the contralateral superficial and deep ILND are performed. Moist laparotomy pads are placed in the wound while awaiting the frozen results.

For a superficial ILND, all tissue superior to the fascia is removed. The superior boundary is 2 to 3 cm above the inguinal ligament. The medial and lateral boundaries are the midpoint of the adductor longus and sartorius muscles, respectively. The inferior border is at or just above the apex of the femoral triangle. Clips, surgical ties, and/or ligature devices should be used to ensure adequate sealing of lymphatic vessels. If possible, the saphenous vein, once identified, should be spared if it is not involved with a grossly suspicious node.

Deep ILND is indicated for clinically positive lymph nodes and/or positive lymph nodes on frozen pathological analysis of the superficial nodal packet. For a deep ILND, the fascia is removed from both the adductor longus and sartorius muscles. The femoral artery and vein are then skeletonized by removing the femoral sheath. Dissection is carried down to the femoral canal, where the node of Cloquet is removed (Figure 1). The nodal packet is then removed and sent for permanent pathological analysis.

For deep ILND and skeletonization of the femoral vessels, it is advisable to perform a sartorius rotational flap to cover the femoral artery and vein (Figure 2). The insertion point of the sartorius muscle at the ASIS is identified and transected. The lateral edge of the muscle is then mobilized using electrocautery. Once the lateral edge of the muscle is free, the muscle is then rotated medially to cover the femoral vessels. A nonabsorbable suture is then used to secure the lateral edge of the muscle to the inguinal ligament. It is important to ensure that the medial aspect of the sartorius muscle is not mobilized, as this is where its blood supply enters.

Upon completion of the ILND, hemostasis is ensured, as well as the sealing of any noticeable lymphatic vessels. The wound is irrigated, and drains are placed. We generally use a single 19 French Jackson-Pratt drain. Patients are counseled that the drain will be in place for an extended period of time until the output is less than 30 cc per 24-hour period (4-6 weeks, typically). A stab incision is made inferior to the flap (but not through it), and the drain is secured to the underlying muscle using 2-0 Chromic suture to render it nonmobile and covering all areas below the flaps. Next, the subcutaneous tissue is closed using 2-0 Vicryl suture. The skin is then closed with either a subcuticular 4-0 Monocryl suture or staples. We routinely leave a 3M Prevena wound vacuum device over the incision, which remains in place for 7 days and can be removed at home by the patient. Importantly, if a wound vacuum device is placed, sealant such as Dermabond should not be placed on the incision.

Complications of ILND

ILND is associated with significant morbidity, with reported complication rates ranging from 50% to 90%.^4-6 Predominant complications include wound issues such as infection, dehiscence, flap necrosis, and seroma formation.^4,5 Lymphedema represents one of the more severe postoperative outcomes, particularly when deep inguinal lymph nodes are excised or when pelvic lymph node dissection is also performed. For this reason, early referral to a lymphedema clinic is advised. Although infrequent, a potential risk of deep venous thrombosis and pulmonary embolism exists with the procedure. Emerging techniques, including robot-assisted ILND, aim to minimize wound-related complications and reduce the overall morbidity associated with the procedure.^5,7

Role of Sentinel Lymph Node Biopsy

The use of sentinel node biopsy (SNB) is an evolving strategy in treating patients with penile cancer with clinically and radiographically negative groins, aiming to minimize the morbidity associated with unnecessary INLD.⁸ Because metastatic spread follows a predictable sequence, SNB involves identifying and sampling the "first landing site" of the lymphatic drainage from the primary tumor, typically using a combination of lymphoscintigraphy (with technetium Tc 99m nanocolloid) and vital blue dye (eg, Patent Blue) to maximize detection.^3,8 A negative SNB result allows patients to avoid the high morbidity of a complete ILND, whereas a positive SNB result mandates proceeding with a full lymph node dissection to achieve oncological control. Despite the biopsy's utility, various sentinel node series have reported false-negative rates between 11% and 29%. Hence, careful patient selection and specialized technique are critical to ensure its accuracy.^3,8

REFERENCES

1. Siegel RL, Kratzer TB, Giaquinto AN, Sung H, Jemal A. Cancer statistics, 2025. CA Cancer J Clin. 2025;75(1):10-45. doi:10.3322/caac.21871

2. Sachdeva A, McGuinness L, Zapala Ł, et al. Management of lymph node–positive penile cancer: a systematic review. Eur Urol. 2024;85(3):257-273. doi:10.1016/j.eururo.2023.04.018

3. NCCN. Clinical Practice Guidelines in Oncology. Penile cancer, version 2.2025. Accessed October 4, 2025. https://www.nccn.org/professionals/physician_gls/pdf/penile.pdf

4. Gopman JM, Djajadiningrat RS, Baumgarten AS, et al. Predicting postoperative complications of inguinal lymph node dissection for penile cancer in an international multicentre cohort. BJU Int. 2015;116(2):196-201. doi:10.1111/bju.13009

5. Ali AA, Schmeusser BN, Nabavizadeh R, Master VA. Minimally invasive techniques to reduce complications of inguinal lymphadenectomy. AME Med J. 2023;8:16-16. doi:10.21037/amj-23-26

6. Gao Y, Shao Y, Hu X, Meng L, Li X. Risk factors for postoperative surgical complications after inguinal lymph node dissection in penile cancer patients. Sci Rep. 2025;15(1):9618. doi:10.1038/s41598-025-94047-5

7. Nabavizadeh R, Petrinec B, Necchi A, Tsaur I, Albersen M, Master V. Utility of minimally invasive technology for inguinal lymph node dissection in penile cancer. J Clin Med. 2020;9(8):2501. doi:10.3390/jcm9082501

8. Leveridge M, Siemens DR, Morash C. What next? Managing lymph nodes in men with penile cancer. Can Urol Assoc J. 2008;2(5):525-531. doi:10.5489/cuaj.922

FIGURE KEY TEXT

Figure 1. Anatomy After Right Deep ILND

A, femoral artery; AL, adductor longus muscle; ASIS, anterior superior iliac spine; IL, inguinal ligament; ILND, inguinal lymph node dissection; N, femoral nerve; PT, pubic tubercle; SM, sartorius muscle; V, femoral vein.

Figure 2. Before and After Sartorius Rotational Flap

A, femoral artery; AL, adductor longus muscle; ASIS, anterior superior iliac spine; IL, inguinal ligament; SM, sartorius muscle; V, femoral vein; X, lateral border of sartorius muscle.