Electrosurgery and curettage

Meet the patient

A 64-year-old man wants "this thing frozen off his back". On the scapula is a 1.2 cm pearly papule with arborising vessels and a rolled border — a clinically typical basal cell carcinoma. He also points to a 6 mm dark, irregular mole on his upper arm and asks whether you can "just burn that one too at the same visit".[8]

Two questions decide what you do next, and they are the two that decide every destructive-procedure case: is the diagnosis certain and low-risk? (the BCC on the back may qualify for C&E; the mole does not) and is there a device, a wet field, or a pigmented lesion in the room? (each one changes the safety plan). Hold those two questions and the whole technique falls into place.[1]

Two words candidates conflate — and the distinction that earns marks

Electrosurgery and electrocautery are not synonyms, and examiners reward the candidate who refuses to use them interchangeably. Electrosurgery delivers high-frequency alternating current through the patient's tissue, so an electrical circuit runs through the body. Electrocautery heats a metal tip with current within the instrument, and the hot tip is applied to tissue — no current passes through the patient.[1]

The distinction matters because only electrosurgery carries the pacemaker-interference and fire risks that dominate the safety half of the viva. The workhorse office device for desiccation and fulguration of small lesions is a hyfrecator — a monoterminal, high-voltage, low-amperage unit.[1][3]

The four modalities — what each does, and why you'd choose it

High-frequency current converts to heat in tissue through resistive (Joule) heating, and the waveform, power, and contact pattern decide whether you dehydrate, char, seal, or cut. Four named modalities cover the office and theatre repertoire.[1][2]

[1]

The circuit rule — mono vs bi. Monoterminal circuits use a single active electrode; the patient's body provides the capacitive return to earth. Biterminal circuits add a large dispersive pad so the current path and heating are controllable and deeper coagulation is efficient — which is also why biterminal energy carries the greater pacemaker-interference risk.[1][2]

Why curettage works — friable tumour versus firm dermis

Curettage works because many basaloid tumours are cohesive enough to feel gritty yet softer than reticular dermis, so the curette shears tumour from a firm base. The operator scrapes until a firm, "squeaky" dermal base is reached, then electrodesiccates the residual microscopic nests at the base and rim. One to three cycles extend the treated field laterally and in depth for selected low-risk tumours.[8][9]

Depth and width of injury depend on waveform, power setting, electrode size, contact time, and tissue impedance — settings are device-specific and not transferable as raw numbers between brands.[2]

Who qualifies for C&E — and who never does

Combined electrodesiccation and curettage is a destructive option for selected low-risk non-melanoma skin cancer and common benign lesions, and the selection — not the energy — is what decides the outcome. The randomised comparison of curettage with cryosurgery for superficial BCC underscores that operator technique and selection drive results, not the brand of destruction alone.[7][9]

[1] [7]

European interdisciplinary BCC guidance places surgery — including Mohs where indicated — at the centre of care, and limits destructive options to carefully selected low-risk disease. A primary, well-defined, non-aggressive BCC, typically under 2 cm, on the trunk or extremities, is the classic C&E candidate; high-risk anatomy and histology belong on an excision or Mohs pathway.[7][8]

The preventable-harm list — never destroy melanoma

Four harms are preventable in this topic, and every one of them is a case-losing error in the viva. None of them is about technique — they are about what you chose to burn, what was wet, and what device was in the patient's chest.[1]

• Never destroy an undiagnosed pigmented lesion. A suspected melanoma or atypical pigmented lesion demands excisional biopsy with a narrow clinical margin — destruction forfeits histology, Breslow depth, and staging, and converts a curable melanoma into an unstageable disaster. Dermoscopy first; if not certain, excise.[1]
• Dry alcohol fully. A spark ignites alcohol vapour and an oxygen-enriched atmosphere. Cleanse, then allow the alcohol-based prep to dry completely before any energy; never drape a pool of alcohol, and be cautious near nasal oxygen.[2]
• Ask about the pacemaker every time. A CIED history is not optional. Prefer bipolar, use short intermittent bursts, keep the active electrode and return path away from the generator and leads, and follow cardiology advice in high-risk cases.[4][5]
• Do not promise clear margins from curettings. Curettings are fragmented and cannot provide a complete margin assessment comparable to an orientated excision. If the question is "is this cancer and is it clear?", choose biopsy or excision, not C&E alone.[8]

[1]

The technique — C&E for low-risk BCC, step by step

The classic teaching sequence for C&E of a low-risk BCC is curette to a firm base, desiccate the base and rim, and repeat — typically one to three cycles. Anaesthetise and stretch the field, then curette the soft tumour firmly until a firm dermal base is felt, extending a few millimetres beyond the visible tumour.[8]

Electrodesiccate the base and a rim of surrounding epidermis, then repeat the curettage of charred soft tissue and re-desiccate. The number of cycles depends on thickness and training tradition — typically one to three — and the wound then heals by secondary intention under an eschar over two to six weeks depending on size and site.[8]

[8]

The consultant confession: if the curette still sinks into soft tissue after two cycles, stop and rethink. A residual soft base may mean deeper or unexpected tumour biology — convert to biopsy or excision rather than delivering endless energy into an uncontrolled field.[8]

Implantable devices — mitigate, do not assume

Electrosurgery can cause electromagnetic interference, inhibition, or rarely reprogramming of a cardiac implantable electronic device, and even hyfrecation is not universally interference-free. Published work documents potential interaction between hyfrecation and implantable cardiac devices, which is why a safety-first office protocol applies to every device patient.[4][6]

Practical mitigations used by dermatologic surgeons: prefer bipolar when coagulation is needed; use short intermittent bursts; keep the active electrode and any return path away from the generator and leads; avoid cutting current when possible; and arrange continuous monitoring or magnet protocols per cardiology advice in high-risk cases.[4][5]

The specimen reality, plume, and complications

Curettings can be submitted for histologic confirmation, but they are fragmented and cannot deliver a margin assessment — and pure hyfrecation of a tag yields no specimen at all. If the clinical question is "is this cancer and is it clear?", choose a biopsy or excision pathway, not C&E alone.[8]

Different electrosurgical techniques generate variable plume; use suction or evacuation and personal protective equipment, because plume may carry particulates and bioaerosols.[10] Complications split cleanly by timing: immediate (pain, bleed, burn beyond field, flash fire), early (infection, delayed ooze, thick eschar), and late (hypopigmentation, hypertrophic scar or keloid, recurrence).[1]

[1]

Special populations and follow-up

Skin of colour carries higher cosmetic stakes — permanent hypopigmentation and keloid risk — so counsel explicitly even for "minor" energy procedures, and choose alternatives on cosmetically critical sites when possible. Immunosuppressed patients carry a higher NMSC burden and recurrence rate, so bias toward margin-controlled surgery for anything beyond clearly low-risk lesions.[7]

For children, brief procedures dominate, and pain and consent are the issues — cotton-tip cryotherapy is often kinder for molluscum than aggressive hyfrecation. In pregnancy, lidocaine local anaesthesia for small procedures is widely used when treatment cannot wait.[1]

For low-risk BCC treated with C&E, structured skin checks and a low threshold to re-biopsy any persistent papule are mandatory — poor selection predicts recurrence more than bad luck. Benign hyfrecation sites usually re-epithelialise within days to a few weeks; C&E wounds heal by secondary intention under eschar.[7][8]

Evidence, guidelines, and regional practice

The JAAD two-part electrosurgery reviews remain the clearest fellowship-level physics and safety backbone.[1][2] Contemporary dermatologic summaries reiterate modality choice and office workflows.[3] European BCC consensus prioritises surgery and restricts destructive modalities to selected low-risk disease.[7]

The mantra, and the mnemonic

[1]

The mantra: electrosurgery through tissue, electrocautery through the tip — and never burn what you cannot diagnose.[1][2]

[1]

Ward-round test

Stem 1 — A 64-year-old man has a clinically typical 1.2 cm pearly BCC on his scapula, and a 6 mm dark irregular mole on his upper arm. He wants both "burned off" today. What do you do for each?[8]

Answer

The scapular BCC is a primary, well-defined, non-aggressive lesion under 2 cm on a low-risk site — C&E is an acceptable option, after confirming the diagnosis clinically and dermoscopically and counselling on scar, recurrence, and follow-up. The dark irregular mole is not for destruction — an undiagnosed or atypical pigmented lesion demands excisional biopsy with a narrow clinical margin, because burning it forfeits Breslow depth, histology, and staging. Dermoscopy first; if not certain, excise.[1][8]

Stem 2 — You are about to electrodesiccate a skin tag on the chest of a patient who mentions, almost as an afterthought, that he has a pacemaker. What changes in your plan?[4]

Answer

A CIED history is not optional. Prefer bipolar coagulation when needed, use short intermittent bursts, keep the active electrode and any return path away from the generator and leads, avoid cutting current when possible, and arrange continuous monitoring or magnet protocols per cardiology advice in high-risk cases. Even hyfrecation is not universally interference-free, so apply a safety-first office protocol to every device patient.[4][5][6]

Stem 3 — During a C&E for a trunk BCC, the curette keeps sinking into soft tissue after two cycles, with no firm dermal base reached. What is the right move, and why?[8]

Answer

Stop and rethink. A residual soft base after two cycles may mean deeper or unexpected tumour biology — infiltrative or morpheaform BCC that C&E will not clear. Convert to biopsy or excision rather than delivering endless energy into an uncontrolled field; high-risk anatomy and histology belong on an excision or Mohs pathway with margin control.[7][8]

Stem 4 — A candidate describes "electrocautery" of a lesion and means a hyfrecator passing current through the patient. Correct them, in one sentence, and name the safety implication.[1]

Answer

Electrosurgery passes high-frequency alternating current through the patient's tissue; electrocautery heats a metal tip within the instrument and applies the hot tip with no current through the patient. The safety implication is that only electrosurgery carries the pacemaker-interference and fire risks that dominate the safety half of the viva — so the distinction is clinical, not pedantic.[1][2]

References

1. [1]Taheri A, Mansoori P, Sandoval LF, et al. Electrosurgery: part I. Basics and principles J Am Acad Dermatol, 2014.PMID 24629361
2. [2]Taheri A, Mansoori P, Sandoval LF, et al. Electrosurgery: part II. Technology, applications, and safety of electrosurgical devices J Am Acad Dermatol, 2014.PMID 24629362
3. [3]Eginli A, Haidari W, Farhangian M, et al. Electrosurgery in dermatology Clin Dermatol, 2021.PMID 34809763
4. [4]Voutsalath MA, Bichakjian CK, Pelosi F, et al. Electrosurgery and implantable electronic devices: review and implications for office-based procedures Dermatol Surg, 2011.PMID 21585593
5. [5]Cervantes JA, Fox MC, Jambusaria-Pahlajani A. Electrosurgery and Implantable Devices: A Survey of Dermatologic Surgeons Dermatol Surg, 2021.PMID 33165061
6. [6]Amin SD, Homan KB, Assar M, et al. Hyfrecation and Interference With Implantable Cardiac Devices Dermatol Surg, 2020.PMID 31652225
7. [7]Peris K, Fargnoli MC, Garbe C, et al. Diagnosis and treatment of basal cell carcinoma: European consensus-based interdisciplinary guidelines Eur J Cancer, 2019.PMID 31288208
8. [8]Marzuka AG, Book SE. Basal cell carcinoma: pathogenesis, epidemiology, clinical features, diagnosis, histopathology, and management Yale J Biol Med, 2015.PMID 26029015
9. [9]Backman EJ, Polesie S, Berglund S, et al. Curettage vs. cryosurgery for superficial basal cell carcinoma: a prospective, randomised and controlled trial J Eur Acad Dermatol Venereol, 2022.PMID 35543079
10. [10]Riopelle AM, Potter CT, Jeong D, et al. Plume Generated by Different Electrosurgical Techniques: An In Vitro Experiment on Human Skin Dermatol Surg, 2022.PMID 36054048