Skin biopsy

Based on s:

• AFP/RACGP 2017 on neoplastic skin disease https://www.racgp.org.au/afp/2017/may/skin-biopsy-in-the-diagnosis-of-neoplastic-skin-di
• AJGP/RACGP 2018 on diagnostic accuracy https://www1.racgp.org.au/ajgp/2018/april/skin-biopsies
• MJA 2020 on practical biopsy technique https://www.mja.com.au/system/files/issues/212_04/mja250473.pdf

Core principle

Skin biopsy is not just a procedural skill. Diagnostic accuracy depends on:

• Choosing the correct lesion.
• Choosing the correct part of the lesion.
• Choosing the correct biopsy type.
• Taking enough depth and width.
• Using the correct transport medium.
• Providing detailed clinical information to the pathologist.
• Clearly stating whether the biopsy is:
  • Partial diagnostic sample, or
  • Attempted complete excision.

This distinction is critical because the pathologist often cannot infer intent from histology alone, and it affects macroscopic processing, margin assessment and final interpretation.

Main biopsy types

Biopsy type	What it samples	Main use	Key limitation
Punch biopsy	Epidermis → dermis → superficial subcutis	Inflammatory dermatoses small diagnostic samples NMSC sampling	Poor for melanocytic lesions if partial limited margin assessment
Shave biopsy	Epidermis ± superficial dermis	Raised/superficial lesions superficial BCC SCC in situ seborrhoeic keratosis	If too superficial, may miss invasive SCC or depth
Deep shave / saucerisation	Epidermis + deeper dermis, intended to remove lesion	Selected – low-suspicion pigmented lesions – superficial lesions	Requires skill; may still compromise Breslow if transected
Incisional biopsy	Representative ellipse/wedge of lesion to subcutis	Large lesions ulcers panniculitis vasculitis deep pathology	Partial sample sampling error possible
Excisional biopsy	Entire lesion with margin	Suspected melanoma keratoacanthoma/SCC deep tumours	Requires more time/skill; may be impractical at some sites
Curettage	Fragmented superficial tissue	Selected low-grade cutaneous malignancy treatment	Histology is fragmented and interpretation can be difficult

Punch biopsy

• Uses a hollow cylindrical blade.
• Blade size varies from 2 mm to 8 mm.
• Samples skin from:
  • Epidermis
  • Dermis
  • Superficial subcutaneous fat
• Most commonly used biopsy type.
• In most settings, a 3 mm or 4 mm punch biopsy is sufficient.
• Useful for many inflammatory, infective and neoplastic skin conditions.

Shave biopsy

• Uses a flexible rectangular blade.
• Samples superficial skin, usually to the level of the dermis.
• Useful for:
  • Epidermal pathology
  • Superficial dermal pathology
  • Raised superficial lesions
• Advantages:
  • Larger surface area sample
  • Usually does not require sutures
  • Quick procedure
• Haemostasis can be achieved with:
  • Direct pressure
  • Aluminium chloride
  • Electrosurgery
• Limitation:
  • May not sample deep dermis or subcutaneous tissue adequately.

Incisional biopsy

Performed with a scalpel, punch or deep shave technique. Removes a representative portion of the lesion rather than the whole lesion. The wound is usually sutured if performed as a scalpel incision or punch biopsy. Useful when:

• the lesion is too large to remove completely
• the lesion is in a cosmetically or functionally difficult site
• deeper tissue is required, including sampling down to subcutaneous fat
• inflammatory dermatoses require deeper sampling, such as:
  • vasculitis
  • panniculitis

The biopsy site should be chosen carefully:

• sample the most clinically active or representative area
• avoid necrotic, ulcerated or heavily excoriated tissue unless this is the target pathology
• use dermoscopy to guide biopsy site selection when relevant

In suspected melanoma, incisional biopsy is not the preferred first-line method, but may be appropriate when complete excision is impractical. In that situation, sample the most atypical or thickest area.

Excisional biopsy

Usually performed with a scalpel. Removes the entire visible lesion with a narrow clinical margin. Usually includes full-thickness skin and a small amount of subcutaneous tissue. Advantages:

• reduces sampling error
• allows assessment of lesion architecture
• allows assessment of depth of invasion
• allows margin assessment
• gives the pathologist the best diagnostic specimen

Preferred biopsy for:

• suspicious pigmented lesions
• suspected melanoma, where technically feasible
• lesions where architecture and depth are important for diagnosis

For suspected melanoma, Australian guidance recommends complete excision biopsy with approximately 2 mm clinical margins where possible.

Definitive wide excision is then planned later according to the histological diagnosis and Breslow thickness.

If complete excision is impractical, for example with a large facial, acral or cosmetically sensitive lesion, a carefully targeted incisional or deep shave biopsy may be considered.

Dermoscopy should be used to guide the biopsy site when the whole lesion is not removed.

Curettage

Uses a sharp spoon-shaped instrument called a curette. Scrapes away abnormal or friable skin tissue. May be used diagnostically or therapeutically in selected lesions, especially some low-risk keratinocyte cancers. Tumour tissue is often more friable than surrounding normal skin, which can help guide removal clinically. Less suitable when precise margin assessment is required. Avoid as the diagnostic method when:

• melanoma is suspected
• a melanocytic lesion is possible
• invasive SCC is suspected
• the lesion is recurrent or high risk
• the lesion is on a high-risk site
• accurate depth or margin assessment is needed

Limitations:

• operator-dependent
• produces fragmented tissue
• specimen orientation is poor
• margin assessment is unreliable
• depth of invasion may be difficult to assess
• histological interpretation can be difficult

Biopsy terminology and intent

• Always tell the pathologist the clinical intent of the biopsy.
• The biopsy may be either:
  • Complete removal of the lesion, or
  • Partial diagnostic sample only.
• Correct terminology matters because the pathologist may not be able to tell intent from the specimen alone.
• Suggested terms:
  • Punch excision = punch used to remove the whole lesion.
  • Punch biopsy = punch used as a partial sample.
  • Elliptical excision = ellipse used to remove the whole lesion.
  • Incisional biopsy = ellipse/scalpel used as a partial sample.
• Avoid simply writing “punch biopsy” if the intent was complete removal.
• This helps prevent confusion about:
  • Whether margins should be assessed.
  • Whether residual lesion may remain.
  • How the specimen should be processed

Choosing biopsy type by clinical scenario

Clinical scenario	Preferred biopsy approach	Rationale / notes
Suspected melanoma / concerning pigmented lesion	Excisional biopsy of entire lesion with ~2 mm clinical margin	Standard approach; allows assessment of – symmetry – architecture – heterogeneity – Breslow thickness
Large pigmented macule / facial lentigo maligna suspicion	Shave/incisional biopsy may be considered if full excision impractical; dermoscopy should guide site	Partial biopsy is higher risk; document lesion size and sampled area
Low-suspicion pigmented lesion on trunk/proximal limb	Deep shave/saucerisation may be acceptable if aiming to remove whole lesion	Best for clinicians experienced with technique
BCC / SCC suspected diagnostic sample before treatment	Small punch biopsy from central lesion, or Shave biopsy of entire lesion if small, portion of lesion if large	Central sample often better yield; preserves margins for later excision
Superficial BCC / Bowen disease	Shave biopsy often appropriate	Superficial pathology; punch may miss discontinuous superficial BCC foci
Actinic keratosis (AK) suspicious for invasive SCC	Adequate shave, punch or excision including dermis	Must include dermal interface to exclude invasion
Hyperkeratotic Actinic keratosis (AK) / thick lesion on hand or forearm	Avoid superficial shave; take deeper sample	Superficial sample may only show dysplasia and fail to exclude SCC
Keratoacanthoma vs SCC	Excisional biopsy if feasible as well-differentiated-SCC cannot be excluded without assessment of the entire lesion	Partial biopsy cannot reliably separate KA from well-differentiated SCC
Seborrhoeic keratosis	Usually clinical diagnosis; shave/excision or partial biopsy if uncertain	Beware melanoma mimicking seborrhoeic keratosis
Macular/papular rash	Punch biopsy of centre of established active lesion	Established primary inflammatory change gives best yield
Annular rash	Punch biopsy of advancing/elevated edge; consider fungal scraping	Edge is diagnostically useful
Vasculitis	H&E: punch of established lesion; DIF: punch of early lesion	DIF requires early lesion
Blistering disorder	H&E: edge of intact blister; DIF: perilesional normal skin within 1 cm	DIF from blister itself may be falsely negative
Ulcer / ulcerated lesion	Incisional biopsy including ulcer edge and adjacent normal skin	Ulcer bed alone is often non-specific
Panniculitis	Deep incisional biopsy to subcutaneous fat	Punch often too shallow
Scarring alopecia	4 mm punch from active edge/area with reduced hairs; consider DIF	Avoid completely bald scarred area
Non-scarring alopecia	4 mm punch; often vertical and horizontal sections	Horizontal sectioning useful for follicular counts

DIF, direct immunofluorescence;

H&E, haematoxylin and eosin; 

Sampling errors — what they are and how to avoid them

Sampling error	Why it happens	Consequence	How to avoid
Wrong part of lesion sampled	Peripheral reactive change sampled instead of tumour	False negative or underdiagnosis	For most neoplasms, sample central diagnostic portion unless necrotic
Partial biopsy of heterogeneous lesion	Lesion contains benign and malignant areas	Melanoma/SCC/aggressive BCC component missed	Excise whole concerning pigmented lesion; use dermoscopy to guide partial biopsy if unavoidable
Superficial shave too shallow	Dermal interface not included	Cannot exclude invasive SCC	Ensure adequate depth into dermis for AK/SCC concern
Central necrosis/ulcer sampled only	Necrotic/inflamed tissue lacks viable tumour	Non-diagnostic report	Include viable lesion edge/central + peripheral lesional tissue
Ulcer bed sampled alone	Ulcer base often non-specific	Misses cause at edge	Incisional biopsy across ulcer edge + adjacent normal skin
Treated/excoriated lesion sampled	Steroid, trauma, crust, infection obscures pathology	Non-specific inflammation	Avoid recently treated, scratched, crusted or infected areas
Punch “excision” assumed complete	Cylindrical specimen gives limited circumferential margin assessment	False reassurance about margins	Use ellipse for true excision; clearly state “punch excision” if intended
Insufficient clinical information	Pathologist lacks morphology, duration, site, differential	Broad or misleading differential	Provide full clinical description, photos, dermoscopy, prior biopsy details
Wrong transport medium	DIF/culture placed in formalin	Test cannot be performed	Formalin for H&E; saline/Michel for DIF; sterile dry container for culture
Crush artefact	Forceps trauma	Histological distortion	Handle gently; lift with needle or minimal forceps

margin assessment problem with punch excision

• Elliptical excision
  • Lesion is usually visible and orientated within the ellipse.
  • The closest margins, usually the side margins, can be deliberately sampled.
  • Margin assessment is more reliable.
  • If marked with a suture, the pathologist can identify which margin is involved, e.g. 12 o’clock, 3 o’clock.
• Punch excision
  • Specimen is cylindrical and small.
  • The pathologist usually bisects it in a relatively random plane.
  • The whole circumferential margin cannot be assessed.
  • A close or positive margin may be missed if it is not in the plane of section.
  • Therefore, a punch “excision” can give false reassurance about clearance.
• Practical implication:
  • Use elliptical excision when accurate margin assessment is important.
  • Be cautious interpreting “clear margins” on punch excision.
  • Clearly document if the lesion was intended to be fully removed by punch.

Pigmented lesions / melanoma

Preferred approach

For clinically concerning pigmented lesions:

• Excisional biopsy is preferred.
• Use a narrow clinical margin, usually about 2 mm.
• Excise to subcutaneous fat.
• Send for H&E histopathology.
• Provide:
  • Lesion size.
  • Exact anatomical site.
  • Clinical and dermoscopic images if available.
  • Whether lesion was fully excised or partially sampled.

Why excision is preferred

Melanoma diagnosis depends on architectural features such as:

• Size.
• Symmetry.
• Circumscription.
• Distribution of atypia.
• Regression.
• Presence of associated naevus.
• Breslow thickness.

Partial biopsy, especially punch biopsy, can miss the malignant component. AFP notes that partial sampling, particularly punch biopsy, increases risk of underdiagnosis; one Australian study reported an odds ratio of 16.6 for misdiagnosis with punch biopsy compared with excisional biopsy.

Why punch biopsy is risky in pigmented lesions

• Melanocytic lesions are often heterogeneous.
• A naevus and melanoma can coexist in the same lesion.
• Melanoma may have areas of regression where diagnostic malignant cells are absent.
• Breslow thickness may be underestimated if the lesion is transected.
• A small punch may create diagnostic uncertainty and trigger further excision anyway.

The AFP article’s page 4 figure illustrates melanoma with areas of regression: one partial biopsy area would diagnose melanoma, while another area could show only dermal scarring and produce a false negative result.

When partial biopsy may be unavoidable

Partial biopsy may be considered when:

• Lesion is broad and facial, with differential of lentigo maligna vs solar lentigo/maculoid seborrhoeic keratosis.
• Lesion is large at another site.
• Lesion is on a functionally sensitive site, e.g. sole.
• Full excision would cause excessive morbidity.

In these cases:

• Use dermoscopy to choose the most suspicious area.
• Mark the sampled site on a clinical/dermoscopic image.
• State clearly: “partial biopsy only”.
• Provide total lesion size.
• Consider dermatologist referral.

Non-melanoma skin cancer: BCC and SCC

BCC / SCC diagnostic biopsy

If sampling before definitive management:

• A small punch biopsy from the central portion of a suspected BCC/SCC is often preferred.
• This avoids creating broad shave-related erythema.
• It preserves lesion margins for later excision.
• It samples the area where deeper/aggressive invasive components are more likely.

Superficial BCC / Bowen disease

Shave biopsy may be more appropriate when:

• Lesion is clinically superficial.
• BCC appears superficial.
• Bowen disease / SCC in situ suspected.
• Lesion is flat or superficial and broad.

For superficial BCC, punch biopsy can miss tumour because superficial BCC may be discontinuous in two dimensions; a punch may sample only stromal reaction.

BCC subtype sampling error

BCC often has mixed growth patterns. Partial punch biopsy may miss an aggressive component in approximately 15% of cases. This matters because infiltrative, micronodular or morphoeic components may alter surgical planning.

Actinic keratosis and suspected SCC

When to biopsy an actinic keratosis

Biopsy is more important if AK has:

• Palpable thickness.
• Rapid growth.
• Bleeding.
• Pain or tenderness.
• Failure of usual topical treatment.
• Hyperkeratosis.
• Suspicion of SCC or SCC in situ.

Biopsy requirement

The specimen must include the deep aspect of the lesion and dermis to distinguish AK/SCC in situ from invasive SCC.

Superficial shave biopsy may confirm dysplasia but may not exclude invasion if dermis is not sampled. AFP notes that one study found invasive SCC in 20% of transected AK shave biopsies that later underwent re-excision, although selection bias likely inflated this estimate.

Keratoacanthoma

Keratoacanthoma classically presents as:

• Rapidly growing dome-shaped nodule.
• Flesh-coloured/pink lesion.
• Central keratin plug.

Problem:

• Clinical and histological overlap with well-differentiated SCC.
• True keratoacanthoma may involute, but SCC may persist or metastasise.
• Partial biopsy usually cannot reliably distinguish KA from SCC.

Best approach:

• Excisional biopsy if feasible.
• Treat clinically as SCC unless specialist/pathology advice indicates otherwise.

AJGP specifically states that excisional biopsy is preferred for keratoacanthoma because well-differentiated SCC cannot be excluded without assessment of the entire lesion.

Inflammatory dermatoses

General rule

For most rashes:

• Biopsy an established active lesion with primary inflammatory change.
• Avoid old lesions with crusting, excoriation, scarring, regeneration or infection.
• Avoid recently treated lesions, especially after topical steroid use if possible.

Site selection

Rash / pathology type	Preferred biopsy site / technique
Macular rash	Punch biopsy from the centre of an established lesion
Papular rash	Punch biopsy from the centre of an established lesion
Annular rash	Punch biopsy from the advancing / raised edge of the lesion. Consider skin scrapings for fungal microscopy/culture if tinea is possible
Polymorphic rash	Multiple biopsies from different lesion morphologies
Petechial rash / suspected vasculitis	Punch biopsy of a fresh early purpuric lesion for H&E. Take an additional biopsy of an early lesion for DIF
Vesicobullous disease	For H&E: biopsy edge of an intact blister, ideally including adjacent normal skin. For DIF: separate punch biopsy of perilesional normal-appearing skin
Cutaneous lupus / connective tissue disease	Punch biopsy of active established lesion for H&E. Additional biopsy may be needed for DIF, depending on the suspected diagnosis
Ulcer	Biopsy the junction of ulcer edge and adjacent normal skin. Avoid necrotic centre alone
Deep pathology, eg panniculitis	Deep incisional biopsy or deep punch biopsy extending into subcutaneous fat

Ancillary tests and transport media

Test	Use	Sample	Transport
H&E histopathology	Routine diagnosis for most inflammatory/neoplastic lesions	Main biopsy specimen	10% buffered formalin
Direct immunofluorescence	Uses fluorophore-labelled antibody complexes. These bind to specific immune deposits or epitopes in the skin. Useful for selected conditions, including: – Autoimmune blistering diseases – Vasculitis – Some genodermatoses Requires appropriate specimen handling. Usually sent in: – Michel medium, or – Saline-soaked gauze if rapid transport is possible Should not be placed in formalin.	Separate biopsy	Normal saline (Saline-soaked gauze) or Michel medium
Microbiology culture	tissue may be examined by: – Microscopy – Culture – Polymerase chain reaction testing Culture involves incubating tissue under specific laboratory conditions so organisms can multiply. Allows: – Identification of pathogens – Antimicrobial sensitivity testing Useful when infection is suspected, including: – Bacterial infection – Fungal infection – Mycobacterial infection – Viral infection, depending on context Usually requires fresh tissue, not formalin-fixed tissue.	Separate fresh tissue	Sterile container, not formalin
PCR / special microbial studies	Selected infections	Discuss with lab	Depends on lab
Cell culture	Skin samples are incubated in special media. Used to grow specific cells, such as fibroblasts. May be used for further specialised testing. Usually relevant for selected genetic, metabolic or research-based investigations.	Fresh tissue	Special medium; discuss with lab

Transport media

Formalin

• Saturated form of formaldehyde in water.
• Acts as both:
  • Fixative
  • Transport medium
• Used for specimens requiring histopathology.
• Preserves tissue architecture.
• Not suitable for:
  • Direct immunofluorescence
  • Microbial culture
  • Fresh tissue studies

Normal saline

• Tissue is placed on saline-soaked gauze.
• Commonly used when fresh tissue is required.
• Can be used for:
  • Direct immunofluorescence, if rapid transport is possible
  • Frozen sections
  • Tissue culture
• Does not provide long-term preservation.

Michel medium

• Special transport medium for direct immunofluorescence.
• Preserves immunoreactants within the skin.
• Allows later immunofluorescence testing.
• Useful when immediate transport to the laboratory is not possible.

Practical biopsy technique: punch biopsy

Preparation

• Confirm indication and consent.
• Photograph lesion/site where useful.
• Mark biopsy site before injecting local anaesthetic.
• Clean skin gently; avoid removing diagnostic scale.
• Use local anaesthetic, commonly lignocaine 1% ± adrenaline.
• Avoid chlorhexidine near ears or eyes due to ototoxicity/ocular injury risk.

Technique

• Hold punch perpendicular to skin.
• Rotate down to superficial subcutis.
• Avoid excessive force.
• Lift specimen gently to avoid crush artefact.
• Cut base with scissors or blade.
• Place immediately in correct transport medium.
• Sutures are usually needed for biopsies >2 mm for haemostasis and cosmesis.

Pathology request form — essential details

Include:

• Patient age and sex.
• Exact anatomical site.
• Morphology: macule, papule, plaque, nodule, ulcer, pigment, scale, keratin, bleeding.
• Size of lesion.
• Duration and evolution.
• Distribution if rash.
• Symptoms: pain, itch, bleeding, rapid growth.
• Clinical impression and differentials.
• Whether biopsy is:
  • Partial diagnostic sample.
  • Punch excision.
  • Elliptical excision.
  • Incisional biopsy.
• Whether the entire lesion has been submitted.
• Prior biopsy result and margins if re-excision.
• Current/recent treatments.
• Medications if drug eruption considered.
• Immunosuppression history if relevant.
• Clinical and dermoscopic images where available.

AJGP stresses that detailed clinical information and accurate macroscopic description improve dermatopathology interpretation and reduce confusing non-correlating reports.

Margin assessment pitfalls

Punch “excision”

A punch may remove a small lesion clinically, but:

• The specimen is cylindrical.
• The pathologist cannot assess the entire circumferential margin.
• Sectioning plane is essentially random.
• A positive/close margin can be missed.

Elliptical excision

Better when complete excision and margin assessment matter because:

• Lesion orientation is clearer.
• Closest margins can be sampled.
• A suture can orient the specimen, e.g. “suture marks 12 o’clock”.
• Pathologist can report specific involved margin.

AFP’s page 2 diagram highlights that punch excisions have random sectioning planes, so margin involvement can be missed, whereas elliptical excision allows more deliberate margin assessment.

Post-procedure care

• Dress with moist occlusive dressing and paraffin ointment.
• Keep dressing undisturbed for 24–48 hours.
• Then clean gently with warm water daily.
• Reapply paraffin ointment and non-stick dressing until re-epithelialised.
• Routine topical antibiotics are not more effective than white soft paraffin.
• Oral antibiotics are not routinely indicated.
• Consider prophylaxis only in selected high-risk patients/sites.

Suture removal timing

Site	Usual removal
Face	5–7 days
Other areas	7–10 days
Back and legs	12–14 days

Follow-up should be arranged to review the wound and discuss pathology results. If pathology does not match clinical suspicion, seek pathology review, second opinion, or dermatology referral.

Red flags for referral rather than GP biopsy

Consider dermatology/plastics/specialist referral if:

• Suspected melanoma in cosmetically/functionally sensitive area.
• Large facial pigmented lesion / possible lentigo maligna.
• Nail unit pigmentation or suspected nail melanoma.
• Lesion on eyelid, lip, nose, ear, genitalia, digit, sole.
• Recurrent tumour or poorly defined margins.
• Immunosuppressed patient with aggressive lesion.
• Rapidly growing painful keratinising tumour where KA/SCC suspected and excision is difficult.
• Clinico-pathological mismatch after biopsy.
• Need for DIF/culture but uncertainty about site/handling.
• Deep panniculitis/vasculitis where adequate subcutis is needed.

Practical algorithm

Step 1 — Define the diagnostic question

Ask:

• Is this inflammatory, infectious, benign neoplastic, NMSC, or melanoma-suspicious?
• Is biopsy for diagnosis only, or diagnosis + treatment?
• Do I need H&E only, or DIF/culture as well?

Step 2 — Decide if biopsy is appropriate in GP

Biopsy in GP if:

• Site is safe.
• Lesion is technically straightforward.
• You can obtain adequate sample.
• You can manage bleeding/wound care.
• You can arrange follow-up and act on result.

Refer if:

• High-risk site.
• High-risk lesion.
• Unclear biopsy strategy.
• Likely need complex excision or staged management.

Step 3 — Choose type

• Suspected melanoma → excisional biopsy, 2 mm margin.
• Suspected superficial BCC/Bowen/SK → shave biopsy.
• Suspected nodular BCC/SCC needing diagnosis → central punch or adequate shave.
• KA vs SCC → excision.
• Inflammatory rash → 4 mm punch.
• Vasculitis/bullous/lupus → punch + separate DIF sample.
• Ulcer/panniculitis/deep lesion → deep incisional biopsy.

Step 4 — Communicate clearly

On request form:

• “Partial diagnostic biopsy only” or “complete excision attempted”.
• Lesion size and site.
• Clinical differential.
• Photos/dermoscopy if available.
• Mark orientation if excision.

Step 5 — Correlate result clinically

• Do not accept benign/non-specific pathology if clinical suspicion remains high.
• Re-biopsy, excise, request deeper sections, discuss with pathologist, or refer.
• For pigmented lesions, partial benign result does not fully exclude melanoma if the lesion remains suspicious.

Key take-home points

• For suspected melanoma: excisional biopsy with ~2 mm margin is standard.
• Avoid partial punch biopsy of pigmented lesions unless unavoidable.
• For suspected invasive SCC arising in AK: sample deep enough to include dermis.
• For BCC/SCC diagnostic sampling: central punch often has better yield than peripheral reactive tissue.
• For superficial BCC/Bowen: shave biopsy is often appropriate.
• For keratoacanthoma: excise if feasible; partial biopsy cannot reliably exclude SCC.
• For inflammatory rashes: choose representative active untreated lesions; early lesions for vasculitis/bullous disease/DIF.
• Always use the correct transport medium.
• Always tell the pathologist whether the sample is partial or intended complete excision.
• Clinical–pathological mismatch should trigger review, repeat biopsy or referral.