Biopsy - Technique

8/20/2019 Biopsy - Technique

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Biopsy Techniques:Skin Lesions


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Indications (indikasi)

• To make or confirm histopathologic diagnoses

(utk membuat atau mengkonfirmasi diagnosishistopatologi )

• Definitive treatment of abnormal, malignant,

and atypical lesions

• Elective removal for cosmetic reasons


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Contraindications

• Infection at biopsy site• Bleeding disorder

• Allergy to local anesthetics


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Risks

• Bleeding– Avoid NSAIDs or ASA 10 days before large excisions

– Switch from warfarin to heparin for large excisions

• Infection

• Scar– More common in children, young adults

– Higher risk areas: mandible, chest, neck, shoulders, hands, feet

– Previous history of keloid formation• Nerve damage

– Face high risk area: facial motor nerve runs very close todermal layer. Nerves run in subcutaneous fat plane.


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Risks

• Allergy to local anesthetics– Type I

• can occur w/o previous exposure. Rare

– Type IV: delayed hypersensitivity.• Needs previous exposure

• Usually local reactions, rash, contact dermatitis.

– Amide agents• lidocaine, mepivicaine, bupivicaine, etidocaine

• Most commonly used agents

• Allergy is EXTREMEMLY rare.

– Ester agents• procaine, tetracaine, chloroprocaine

– Bacteriostatic saline or injectable diphenhydramine• Mild anesthetic effect. Lasts 15 minutes.


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Risks

• Allergy to topical antibiotics

– Neomycin. 3rd most common contact allergen in U.S.– Bacitracin. 6th most common contact allergen in U.S.


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Description of Lesion

Flat

• Macule < 1 cm

• Patch > 1 cm

Raised

• Papule < 1 cm

• Nodule 1-2 cm

• Tumor > 2 cm

• Plaque. Flat,

elevated with

surface area >

height.

• Indurated. Firm

Pedunculated


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How to chose your biopsy type ?

• Flat– Punch or ellipse

• Raised– Punch or ellipse if worried about melanoma

– Shave in other cases

• Indurated– Punch or ellipse

• Pedunculated

– Shave or scissors


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Where should I biopsy?

• Pigmented lesion– Excise entire specimen. 1-3 mm margins

• Rash– Developed but not excoriated lesion

–Multiple biopsies– Biopsy at edge of lesions

– 4 mm punch

• Blistering disorder– Excise entire blister or at blister edge

• Formalin for histopathology– Biopsy peri-lesional normal skin

• Saline soaked gauze for Direct Immunoflorescence (DIF)


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How deep should you go?

• Punch & elliptical biopsies

• When concerned about melanoma

Prognosis based on depth

• Easier extraction of specimen

• Shave biopsies

• Raised or pedunculated

• Not worried about

melanoma

Through epidermis/dermis into

subcutaneous fat

Through epidermis &

dermis


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Supplies & Instruments

• Prep solution– Isopropyl alcohol, povidone-iodine, chlorhexadine

• Drapes

• Gauze• Syringes• Needles

– 18 or 20 G to draw up. 25 or 30 G to inject.

• Anesthetic– Lidocaine (0.5, 1 or 2%) with or without epinephrine– Epinephrine okay to use on digits/acral areas


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Supplies & Instruments

• Punch biopsy (3mm-8mm)

• # 15 blade scalpel

• Iris scissors, forceps with teeth, needle driver

• Suture– Nylon, absorbable or prolene (blue)

– 4-0 or 5-0 with P-3 or FS-3 needle. 6-0 on face.

• Hemostatic agent– Aluminum chloride (Drysol)

– Silver nitrate sticks. May stain skin brown• Processing solution (formalin, saline, etc)

• Dressing supplies


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Shave biopsy

• Create wheal to elevatelesion

• Stretch & stabilize skin• #15 blade held parallel

to skin

• Smooth sweeping strokes

• Near end of excision, place forceps on top of lesion to

stabilize and prevent tearing with exit of blade


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Punch Biopsy

• Determine direction of skin tension

lines

• Stabilize skin with thumb/forefinger

• Consider stretching skin perpendicular

to skin lines to create ellipse

• Place punch perpendicular to skin

• Apply firm downward pressure with acircular motion until reach sub-Q fat.

Will feel “give”

• Forceps to remove lesion. Cut at base


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Fusiform (Elliptical)

Excision

• Align long axis of excision parallel to skin tension lines• Draw ellipse

– 2-5 mm wound margins– 30 degree angles at each apex– Length is 3-4 times the width

• #15 blade scalpel

• Undermine at level of sub-Q fat with scalpel or scissor• Place stitch at one end of biopsy sample

– Helps to identify orientation of sample

• Undermine wound edges in preparation for suturing


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Processing biopsy specimens

• Histopathology– 10% buffered formalin

• Direct immunoflorescence

– Dx of blistering disease, SLE, etc.– Michel’s solution

– Saline soaked gauze. Do not let specimen dry out

• Bacterial or fungal cultures

– Sterile container with nonbacteriostatic saline• Viral studies

– Viral transport media


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To suture or not to suture?

• Does this biopsy need a stitch?– RCT comparing primary (suture) vs secondary healing

in 4 mm vs. 8 mm punch biopsies.• Doctors: no difference in healing or cosmesis

in 4 mm or 8 mm biopsies.• Patients: no difference in healing or cosmesis

in 4 mm biopsy. Better cosmesis with suture in 8 mm bx.

• Sutures-- Monofilament nylon (Ethilon)-- Polypropylene (Prolene)

• What about absorbable sutures?– Some evidence: absorbable polyglactin (Vicryl) suturesequal to nylon sutures in rates of infection, redness,dehisence, scar hypertrophy, patient satisfaction.


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Simple Suture


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Vertical Mattress Suture


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Post Procedure Care

• Wounds heel faster when moist– Vaseline or antibiotic ointment

• Occlusive or semi-occlusive dressing• Remove bandage after 12-24 hrs

• Cleanse with soap/water twice daily

• Bandage for approx 5 days or until re-epithelialized

• Shower okay with sutures. Avoid soaking

• Avoid activities that will put stress on sutures


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Suture Removal

• Face

– 4-6 days; apply Steri-Strips

• Chest, abdomen, upper extremities, scalp

– 7-10 days

• Back, lower extremities– 12-20 days


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Pathology Forms: Essential Information

• The 6 D’s

Demographics: age, gender, ethnicity

Description:

-location, color, symptoms, other areas of involvement,previous therapy or biopsy.

Diseases & Drugs

Duration of condition

Diameter of lesion or eruption

Diagnosis: in order of likelihood-Can be broad categories such as malignancy,

dermatitis, infection.

-Avoid terms like “rule out”


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Documentation

• Diagnosis: Reason for procedure

• Description and location of lesion

• Procedure: Shave vs. Punch vs. Ellipse• Consent: Risks and benefits reviewed

• Prep and Anesthesia

• Description of procedure

• Specimen disposition

• Patient education and follow-up


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Follow-up of pathology results

• No uniform recommendations

• Interpretation requires understanding ofclinical scenario

• Work closely with your dermatologist

• Get to know YOUR dermatopathologist


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The End

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Biopsy - Technique