A resident’s guide to skin cancer minor surgery

INTRODUCTION

Local anesthetic lists are a daily facility within skin cancer units in the United Kingdom (UK) and are an excellent training opportunity for even the most junior resident doctors.¹ There are an estimated 22,000 cancer patients, including those with skin cancer, awaiting appointments according to Cancer Research UK,² so the expanded use of residents to participate in the diagnosis and treatment of skin cancer is an avenue worth exploring.

Despite their ambitious aims to deal with the more complex skin cancer and reconstructive cases, residents in dermatology and plastic surgery need to have a solid foundation of basic surgical skills in the context of oncological surgery when conducting even the simplest of cases.

COMMON SKIN CANCERS

Basal cell carcinoma (BCC) is a common and slow-growing, locally invasive skin cancer with a low risk of metastasis.³ It typically appears as pearly or translucent nodules with telangiectasia on sun-exposed areas.

Squamous cell carcinoma (SCC) carries a higher risk of metastasis and typically presents as keratotic nodules with a central crater of crust with a shorter period of growth.³

Melanoma leans toward the more aggressive end of the spectrum of skin cancers arising from melanocytes. They typically have a pigmented appearance with irregular borders and color distribution. Potential symptoms include itching, bleeding, or simply a sudden change in the appearance of a preexisting mole. It can progress quickly and has high metastatic potential.⁴

Early diagnosis and treatment of skin cancer is crucial for reducing morbidity, mortality, and recurrence rates. Patients often need ongoing follow-up in the community or under a member of the skin cancer multidisciplinary team due to likely actinic field change posing the risk of further skin cancers. Surgery is often the first-line treatment for many skin cancers because it facilitates histological diagnosis and offers definitive treatment.

There are several definitions that residents need to appreciate.

DEFINITIONS

LOCAL ANESTHESIA ADMINISTRATION

Inject your local anesthetic in parallel to sensory nerve orientation, giving this 1^st injection a moment to work before administering the remainder.¹⁰ Subsequent injections should be less sensitive. Avoid injecting into the skin lesion directly, reducing the theoretical risk of seeding potential tumors elsewhere [Figure 1].

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Figure 1:

Administering local anesthetic agent in the direction of sensory nerve.

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As you inject, observe if the lesion elevates off underlying structures (fascia/bone) or if it remains fixed. Depending on anatomical location and defect size, fixity may increase the complexity of the reconstruction required.

When using adrenaline, allow its hemostatic effects to have time to work. Consider administering the injection, drafting your paperwork, and then scrubbing for the case. This will reduce the tendency to start before it has had any hemostatic effect while maintaining some operative efficiency.

SURGICAL TECHNIQUE

Good oncological practice requires you to obtain a specimen that is histologically examinable and uncrushed without contamination of neighboring skin. Techniques to uphold this include:

1. Use of a different needle for injection of local anesthetic for each skin cancer being excised on the same patient

2. Skin preparation of normal skin first, then the cancer site; the reverse will seed “dirty” to clean

3. Avoid overhandling the specimen with forceps; a skin hook for retraction may be less traumatizing¹¹

4. Avoid gauze used for absorbing blood also brushing the cancer and then resting on normal skin

5. Remove instruments used for excision and use fresh instruments and gauze for closure of skin

6. Where multiple tumors are being excised, use a fresh suture for each closure. The leftover of one suture can be used for the marker suture; a clip can be placed on the specimen for orientation until the marker suture is placed

SCAR ORIENTATION WITH ANATOMICAL CONSIDERATIONS

Limbs

Where possible, mark your elliptical extension in a vertical orientation. Laxity is circumferential, lymphatics run longitudinally, so you preserve more this way, reducing edema. If subsequent excision and reconstruction are required, a vertical orientation is usually favorable [Figure 2].¹²

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Figure 2:

(a) Skin lesion marked, (b) marking the lesion to make a longitudinal orientation drawing maximum laxity, (c) excision margins marked with edges touching the ellipse, (d) post-excision of lesion – longitudinally oriented scar.

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Face

Mark the margins, usually circular, and excise as a circle in the first instance. Skin is elastic, and the orientation of the different muscle fibers of the face often allows you to draw laxity from different directions to support closure without an ellipse. Any excess skin that creates a standing cone (dog ear) can be removed at the end, often a smaller (burrows) triangle than your predicted pre-marked ellipse [Figure 3].

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Figure 3:

Skin lesion marked with edges making a circle.

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Lower lid

A vertical orientation is more favorable to a transverse scar. The latter has a greater risk of causing ectropion [Figure 4].

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Figure 4:

Skin lesion marked, (b) post-excision of skin lesion – vertically oriented surgical wound.

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Trunk

Assess the direction of the Resting Skin Tension Lines (RSTLs). Mark the lesion’s margins, and extend this into an ellipse into these RSTLs. Consider the movements that will put this wound under the most tension. The closure needs to withstand this [Figure 5].

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Figure 5:

(a) Edges of skin lesion marked, (b) marking with adequate excision margin, (c) making an ellipse in the direction of resting skin tension line, (d) post-excision of lesion

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LEARNING POINTS

1. The intent of the procedure, diagnostic or therapeutic, determines the margin for excision.

2. Give local anesthetic with consideration to the direction of sensory nerves.

3. Sound oncological surgical practice will prevent the risk of tumor seeding to the local area.

4. The orientation of scars should be optimized to the anatomical site and local structures 5. Mohs micrographic surgery should be actively considered for high-risk cases.

CONCLUSION

Skin cancer minor surgery provides a valuable training ground for junior residents to develop essential procedural skills within the context of oncological care. A sound understanding of excision principles, appropriate anesthetic techniques and lesion handling is key to achieving clear margins and reducing the risk of recurrence. Careful planning of scar orientation, appropriate margin selection and clear documentation support both patient outcome and clinical learning. Early exposure to structured techniques lays a strong foundation for future practice in skin cancer surgery.