3/17/2017 Basic Dermatology Procedures Basic Dermatology Procedures for the Non‐dermatologist • Liquid Nitrogen • Skin Biopsies Lindy P. Fox, MD • Electrocautery Associate Professor Director, Hospital Consultation Service Department of Dermatology University of California, San Francisco [email protected] I have no conflicts of interest to disclose 1 Liquid Nitrogen Cryosurgery 1 3/17/2017 Liquid Nitrogen Cryosurgery Liquid Nitrogen Cryosurgery Principles • Indications • ‐ 196°C (−320.8°F) – Benign, premalignant, in situ malignant lesions • Temperatures of −25°C to −50°C (−13°F to −58°F) within 30 seconds with spray or probe • Objective – Selective tissue necrosis • Benign lesions: −20°C to −30°C (−4°F to −22°F) • Reactions predictable • Malignant lesions: −40°C to −50°C. – Crust, bulla, exudate, edema, sloughing • Post procedure hypopigmentation • Rapid cooling intracellular ice crystals • Slow thawing tissue damage – Melanocytes are more sensitive to freezing than • Duration of THAW (not freeze) time is most keratinocytes important factor in determining success Am Fam Physician. 2004 May 15;69(10):2365‐2372 Liquid Nitrogen Cryosurgery • Fast freeze, slow thaw cycles – Times vary per condition (longer for deeper lesion) – One cycle for benign, premalignant – Two cycles for warts, malignant (not commonly done) • Lateral spread of freeze (indicates depth of freeze) – Benign lesions 1‐2mm beyond margins – Actinic keratoses‐ 2‐3mm beyond margins – Malignant‐ 3‐5+mm beyond margins (not commonly done) From: Bolognia, Jorizzo, and Schaffer. Dermatology 3rd ed. Elsevier 2012 2 3/17/2017 Liquid Nitrogen Cryosurgery Cryosurgery for Common Warts Technique • Hold spray gun 1‐1.5cm away from target • Freeze time 20‐60 seconds • Freeze until ice field fills the margin • Margin‐ 2‐3mm • Thaw 30‐45 seconds • Maintain the spray for the appropriate time • TWO cycles better than one BEYOND initial time of ice field formation • Repeat every 3‐4 weeks • If more than one cycle required, allow for • Average # of warts cleared= 40% complete thawing before beginning next cycle • Average # of treatments to clear warts = 12 – ONE YEAR! 3 3/17/2017 Cryosurgery for Planar Warts Cryosurgery for Actinic Keratoses • One freeze‐thaw cycle • May consider • margin‐ 2‐3mm cotton tipped • Freeze time applicator – AK 5‐7s technique – Actinic cheilitis 10‐20s www.dermquest.com Cryosurgery for Seborrheic Keratoses Cryosurgery for Lentigines • Freeze‐ thaw cycle • Quick 3‐4s freeze depends on thickness • Avoid overfreezing • Thin/flat‐ freeze 5‐10s – Risk of hypopigmentation • Large/thick‐freeze >10s, may need second cycle 4 3/17/2017 Cryosurgery for SCC in situ* • One 30 second freeze Or • Two 20 second freezes • Close follow up Skin Biopsies *ED+C still preferred treatment option Skin Biopsy Skin Biopsy Types • Procedure itself is easy • Curettage • Knowing when and where to biopsy much • Snip/scissors more difficult • Shave biopsy • Pathologist can only comment on the tissue • Saucerization provided (not what’s left on patient) • Punch • Potential pitfalls in technique • Incisional • Excisional (in toto) 5 3/17/2017 Curettage with Biopsy • Samples epidermis only • Clinically benign lesions involving the epidermis – Verrucae (warts), seborrheic keratoses, actinic keratoses • Send pathology at same time as treating the lesion • Limitations – Limited to the epidermis • Hold like pencil • Draw pressure under the lesion (epidermis) – Fragmented tissue From: Bolognia, Jorizzo, and Schaffer. Dermatology 3rd ed. Elsevier 2012 Snip/Scissors Biopsy • Pedunculated lesions • Benign growths – Acrochordons (skin tags) – Filiform warts – Pedunculated nevi • If very thin attachment to skin (stalk) don’t need anesthesia • Use iris or Gradle scissors • May require hemostasis with aluminum chloride, electrodesiccation From: Bolognia, Jorizzo, and Schaffer. Dermatology 3rd ed. Elsevier 2012 6 3/17/2017 www.hovesskinclinic.co.uk Shave Biopsy • Samples epidermis and papillary (superficial) dermis • Ideal for elevated lesions involving the epidermis and superficial dermis – Inflammatory dermatoses of epidermis, superficial dermis (psoriasis, eczema, CTCL, lichen planus) – Nevi, benign adnexal tumors – Diagnosis of basal cell or squamous cell carcinoma – Diagnosis of lentigo maligna (MIS) Onsurg.com Am Fam Physician. 2011 Nov 1;84(9):995‐1002 Good Shave Biopsy • Be sure to get below simple hyperkeratosis and upper dermis • Palms, soles, hyperkeratotic lesions • Require hemostasis with aluminum chloride, electrodesiccation rd From: Bolognia, Jorizzo, and Schaffer. Dermatology 3 ed. Elsevier 2012 Slide courtesy of Jeff North, MD 7 3/17/2017 Saucerization Biopsy • Deeper biopsy with intentional deeper placement of the blade • Samples epidermis and superficial and deep dermis • Advantage – Histologic examination of the entire circumference of the lesion with adequate depth to assess invasion • Ideal for – Inflammatory dermatoses with dermal infiltrate • – Atypical pigmented lesions (to r/o melanoma) Intention is to get to deep dermis • Requires hemostasis with aluminum chloride, electrodesiccation – Keratoacanthoma/SCC From: Bolognia, Jorizzo, and Schaffer. Dermatology 3rd ed. Elsevier 2012 Punch Biopsy Punch Biopsy • Samples epidermis, dermis and superficial subcutaneous fat • Varying barrel sizes‐ 2mm‐ 8mm • Ideal for – Inflammatory dermatoses with deep dermal infiltrate (lupus) – Infiltrative diseases (amyloid, sarcoid, lymphoma cutis) – Blistering diseases (pemphigus, pemphigoid) – Depressed lesions (scleroderma) • Limitations • Stabilize skin around punch with free hand – Only samples portion of larger lesion – Requires suture (>3mm) • Twist with firm downward pressure in one direction – Not ideal for subcutaneous lesions • Gently lift tissue with forceps at edge of epidermis (do not crush) • NO contraindications to punch biopsy other than avoiding • If plug not elevating, angle scissors downward to base bowel and brain • Try to make sure there is some fat at the base of the sample Slide courtesy of Wilson Liao, MD 8 3/17/2017 Good Punch Biopsy Incisional Biopsy • Samples epidermis, dermis, subcutaneous fat • Removes wedge from center or edge of lesion • Ideal for – Large tumors – Subtle diseases of connective tissue – Diseases of the fat (panniculitis) – Diseases of the fascia Slide courtesy of Jeff North, MD Excisional Biopsy • Samples epidermis, dermis, subcutaneous fat • Intended to be definitive treatment • Ideal for – Suspected invasive melanoma From: Bolognia, Jorizzo, and Schaffer. Dermatology 3rd ed. Elsevier 2012 9 3/17/2017 Skin Biopsies‐ Potential Pitfalls Crush Artifact • Crush artifact • Leaving part of tissue in punch tool • Multiple specimens, mislabeling Slide courtesy of Jeff North, MD Failure to Deliver Multiple Biopsy Specimens • Leaving part of the biopsy in the punch tool • Critically important to have an established protocol/routine to ensure the correct biopsy goes in the correct bottle Biopsy A B C Slide courtesy of Jeff North, MD Slide courtesy of Jeff North, MD 10 3/17/2017 Shave Biopsy Tray Video courtesy of Wilson Liao, MD Punch Biopsy Tray 11 3/17/2017 How to biopsy a specific lesion Where to Biopsy Lesion Type of biopsy Lesion Location of biopsy Papulosquamous (eczema, Shave or saucerization biopsy Tumor Thickest portion, avoid necrotic tissue psoriasis) r/o melanoma Saucerization or excisional biopsy Blister Edge of the lesion, include about 2mm of blister edge; send for H+E and DIF Blister Punch biopsy at the edge for H+E and DIF Ulceration/necrotic Edge of ulcer or necrosis plus adjacent lesion skin Wart, seborrheic keratosis, Shave biopsy or curettage Generalized Characteristic lesion of recent onset (+/‐ actinic keratosis polymorphic eruption more developed lesion) Small vessel vasculitis Characteristic lesion of recent onset Scalp (alopecia) Punch biopsy from hair containing region (palpable purpura) (ideally <24 hours old) adjacent to alopecia, request transverse sections Adapted from: Bolognia, Jorizzo, and Schaffer. Dermatology 3rd ed. Elsevier 2012 Direct Immunofluorescence • Location of the biopsy depends on differential diagnosis • Michel’s medium (not formalin) • Vasculitis‐ lesional skin from an early lesion • Lupus – DLE/SCLE Lesional skin – SLE‐ Lesional, uninvolved can be positive as well • Blistering – Peri‐lesional Slide courtesy of Jeff North, MD Slide courtesy of Jeff North, MD 12 3/17/2017 DIF in Pemphigoid and Pemphigus DIF in Other Immunobullous Disease • Dermatitis herpetiformis DIF‐ peri‐lesional • Eclipsing the edge of new • Up to 1 cm away from lesion blister • Don’t overlap the clinical lesion • Being too far from a blister • Higher risk for loss of epidermis and can cause false negative DIF destruction of Ig by the neutrophilic inflammatory infiltrate • Serology: anti‐transglutaminase and anti‐ endomysium antibodies also helpful Slide courtesy of Jeff North, MD Slide courtesy of Jeff North, MD Photo courtesy of Kari Connolly, MD Electrosurgery • Electrodesiccation – Superficial tissue destruction Electrosurgery • Electrocoagulation – Deep tissue destruction • Electrosection – Cutting 13 3/17/2017 Electrosurgery Electrodesiccation • Electrodesiccation • Damped, high‐ voltage current – Superficial tissue destruction • Causes superficial • Electrocoagulation tissue damage via – Deep tissue destruction dehydration • Electrosection – Cutting Electrodesiccation and Electrofulguration Electrodesiccation Indications‐ Epidermal Lesions Electrodesiccation Electrofulguration • Acrochordons • Actinic keratosis • Angioma (small)