1Actinic Keratosis & Squamous Cell Carcinoma Medical Student Core CurriculumIn DermatologyUpdated September 5, 2011
2Module InstructionsThe following module contains a number of underlined terms which are hyperlinked to the dermatology glossary, an illustrated interactive guide to clinical dermatology and dermatopathology.We encourage the learner to read all the hyperlinked information.
3Goals and ObjectivesThe purpose of this module is to help medical students develop a clinical approach to the evaluation and initial management of patients presenting with suspicious lesions.By completing this module, the learner will be able to:Identify and describe the morphology of actinic keratosesIdentify and describe the morphology of squamous cell carcinoma Initiate appropriate workup for suspicious lesionsRecognize high risk factors for development of squamous cell carcinoma, including organ transplant and immunosuppressionRefer patients with skin lesions suspicious for non-melanoma skin cancer to dermatology
5Case One: HistoryMr. Dominguez is a 70-year-old man who presents to your office with a red, crusted bump on his right forearm.He first noticed the growth about 6 months ago. It has been increasing in size. It is sometimes itchy but never painful and has bled after minor traumas. The growth feels dry and rough, but applying lotion does not make it better.
6More History Past Medical History: Medications: Family History: History of extensive sun exposure as a teenSometimes burns, always tans (Fitzpatrick skin type IV)No history of skin cancerNo history of arsenic exposure or radiationMedications:Vitamin DFamily History:Social History:Married with 2 children. Worked in landscaping.Health-Related Behavior:Non-smoker. No alcohol or drug use.
7Case One: Skin ExamHow would you describe Mr. Dominguez’s growth?
8Case One: Skin ExamWell-circumscribed, 2cm, erythematous nodule with central ulceration and crust. The lesion is firm with palpation.
9What is your differential diagnosis? After you have considered the differential diagnosis,click next for a list of possible diagnoses.
10What is your differential diagnosis? Actinic keratosisBasal cell carcinomaMelanomaSeborrheic keratosisSquamous cell carcinomaVerruca vulgaris
11Management What is your next step in management? Liquid nitrogen cryotherapyReassurance with close follow-upShave biopsySurgical excisionTopical antibiotics
12Management Answer: c What is your next step in management? Liquid nitrogen cryotherapy (Would not treat the lesion with cryotherapy without knowing the diagnosis. This is a suspicious lesion that warrants a biopsy)Reassurance with close follow-up (A history of a new growing lesion with concerning characteristics warrants a biopsy)Shave biopsy (Before treating this lesion, you must establish a diagnosis)Surgical excision (You must know the diagnosis before you can plan treatment with surgical excision and surgical margins)Topical antibiotics (The lesion is not an infection)
13Shave biopsy reveals… Scanning magnification: Normal epidermis Dermal extension of well-differentiated (“keratinizing”) keratinocytes
14Shave biopsy reveals…High power view:Variably-sized keratin pearls
15Diagnosis What is your diagnosis? Click on the correct answer. Actinic keratosisBasal cell carcinomaMelanomaVerruca vulgarisSeborrheic keratosisSquamous cell carcinoma
16What is your diagnosis? That was incorrect. Try again. Actinic keratosisBasal cell carcinomaMelanomaVerruca vulgarisSeborrheic keratosisSquamous cell carcinoma
18Squamous cell carcinoma (SCC) Most commonly occurs among people with white/fair skinCommonly located on the head, neck, forearms, and dorsal hands (sun-exposed areas)SCC has increased associated mortality compared to basal cell carcinoma, mostly due to a higher rate of metastasis
19SCC: Etiology Cell of origin: keratinocyte Cumulative UV exposure Cause genetic alterations, which accumulate and provide selective growth advantageSCC arising in non sun-exposed areas may be related to chemical carcinogen exposure (e.g. arsenic)
20SCC: Clinical manifestations Various morphologiesPapule, plaque, or nodulePink, red, or skin-coloredScaleExophytic (grows outward)Indurated (dermal thickening, lesion feels thick, firm)May present as a cutaneous hornFriable – may bleed with minimal trauma and then crustUsually asymptomatic; may be pruritic
22SCC in situ Also known as Bowen’s disease Circumscribed pink-to-red patch or thin plaque with scaly or rough surfaceKeratinocyte atypia is confined to the epidermis and does not invade past the dermal-epidermal junction
23Back to Mr. DominguezMr. Dominguez was diagnosed with invasive SCC. What is your next step in management?Liquid nitrogen cryotherapyReassurance with close follow-upShave biopsySurgical removalTopical antibiotics
24Management Answer: d What is your next step in management? Liquid nitrogen cryotherapy (Liquid nitrogen is used to treat pre- cancerous actinic keratoses. It is NOT the treatment for invasive squamous cell carcinoma.)Reassurance with close follow-up (Squamous cell carcinoma is a malignant lesion with potential for metastases. You must treat it!)Shave biopsy (You already know the diagnosis and there is no need for another biopsy.)Surgical removal (The treatment of choice for squamous cell carcinoma is surgical excision. The specimen must be sent to pathology to document clear margins (complete excision).)Topical antibiotics (The lesion is not an infection.)
25Pathology reports for SCC “Invasive squamous cell carcinoma”Means there are SCC cells in the dermisIf there is no dermal involvement, it is squamous cell carcinoma in situUnrelated to metastatic potential“Atypical squamous proliferation”Often used when biopsy is too superficialIf dermis cannot be seen in the biopsy, invasive SCC cannot be excluded
26SCC: TreatmentThere are several medical and surgical treatment optionsSuspicion of SCC should prompt referral to a dermatologist for evaluation and discussion of specific treatment approachesSurgical Treatment OptionsSurgical excision (standard of care for invasive SCCs)Wide local excisionMohs micrographic surgeryCurette and Desiccation (reserved for in situ SCC)Non-surgical Treatment OptionsRadiation therapy for poor surgical candidates5-Fluorouracil cream, imiquimod cream, photodynamic therapy – typically reserved for in situ SCCs when excision is a suboptimal choice
27SCC: Course & Prognosis For SCC arising in sun-exposed skin, the rate of metastasis to regional lymph nodes ~ 5%Higher rates of metastasis if:Large (diameter > 2cm), deep (> 4mm), and recurrent tumorsTumor involvement of bone, muscle, and nerveLocation on scalp, ears, nose, and lipsTumor arising in scars, chronic ulcers, burns, sinus tracts, or on the genitaliaImmunosuppressed patientsTumors caused by arsenic ingestion
28Patient Follow-upAll patients treated for cutaneous SCC need surveillance for the early recognition and management of:Treatment-related complicationsLocal or regional recurrencesDevelopment of new skin cancersPatients with a history of SCC should have close follow-upPatients are often seen every 6 to 12 months
30How would you describe the skin findings? Case Two: HistoryMr. Jenkins is a 66-year-old man with a history of SCC who presents to the dermatology clinic for his regularly scheduled follow-up visit. He reports that during a self skin exam, he noticed a few rough, red spots on the face. He asks if this could represent another cancer.How would you describe the skin findings?
31Case Two: Skin ExamRough, scaly, thin, red-pink plaques scattered on the forehead and right temple area
32Diagnosis What is your diagnosis? Click on the correct answer. Actinic keratosisBasal cell carcinomaMelanomaSeborrheic keratosisSquamous cell carcinomaVerruca vulgaris
33Diagnosis That was incorrect. Try again. Actinic keratosis Basal cell carcinomaMelanomaSeborrheic keratosisSquamous cell carcinomaVerruca vulgaris
35Actinic Keratosis (AK) AKs are premalignant lesions; they have the potential of transforming into a skin cancer. Virtually all AKs that transform into cancer will become squamous cell carcinoma (SCC).Most AKs do not progress to invasive SCCRisk of malignant transformation of an AK to SCC within one year is about 1 in 1000Risk factors for malignant progression of AK to SCC include: persistence of the AK, history of skin cancer, and immunosuppressionThe keratinocyte is the cell of origin
36SCC in situ (Bowen’s disease) Actinic KeratosisAKs may be considered as part of a disease spectrum:Photodamaged SkinActinic KeratosisSCC in situ (Bowen’s disease)Invasive SCC
37AK: Etiology Cumulative and prolonged UV exposure, resulting in: UV-induced p53 tumor suppressor gene mutationsIndividual risk factors can increase susceptibility:Increasing ageFair skin, light eyes/hair (skin types I,II)ImmunosuppressionGenetic syndromes, such as xeroderma pigmentosum and albinism
38AK: Clinical manifestations May be symptomatic (tender)Located in sun-exposed areasHead, neck, extensor forearms, and dorsal handsTypically on background of sun damaged skinErythematous papule or thin plaque with a characteristic rough, gritty scaleOften diagnosed by feel (like sandpaper)* The diagnosis of AKs should be made cautiously in lesions > 6mm since these may represent SCC in situ or a superficial BCC.
40Recognizing Sun-damaged Skin Skin features of chronic sun damage include:Combination of atrophy and hypertrophyTelangiectasiasSpotty depigmentation and hyperpigmentationWrinklesSkin appears “leathery” and “prematurely aged”
41Solar Lentigo (lentigines) Result from UV damageSun-exposed areasOne/many small brown macules
42Effects of Sun Damage Cutis rhomboidalis nuchae (red neck with rhomboidal furrows)Solar Elastosis(fine nodularity, pebbly surface)
43Actinic (senile) Purpura Easy bruisingExtravasated erythrocytes and increased perivascular inflammation
45AK: Actinic cheilitisActinic cheilitis represents AKs on the lips, most often the lower lipErythematous patch with rough gritty scale involving the lower lipPersistent ulcerations or indurated areas should prompt a biopsy to rule out malignant transformation
46How would you treat this AK? Which of the following treatments would you recommend for this AK?Liquid nitrogen cryotherapySurgical excisionRadiation therapyTopical antibioticTopical corticosteroids
47How would you treat this AK? Answer: aWhich of the following treatments would you recommend for this AK?Liquid nitrogen cryotherapySurgical excisionRadiation therapyTopical antibioticTopical corticosteroidsClick here to view a video on cryotherapy
48AK: TreatmentThere are several topical and procedural treatment options for AKs. The best option is chosen after consideration of number, location, and thickness, among other patient factors.Therapies are considered local – treating the individual lesion, or field therapies – treating multiple AKs in one areaConsultation with a dermatologist to guide therapy may be usefulLocalized TherapiesField TherapiesLiquid nitrogen cryotherapyTopical 5-fluorouracil or imiquimod creamsCurettage +/- electrocauteryPhotodynamic therapyShave excision
49AK: Patient EducationPatients with AKs are at increased risk of developing other non-melanoma and melanoma skin cancers.Therefore, these patients should have regular skin exams every 6-12 monthsPatients should be seen prior to their regularly scheduled follow-up if they notice a concerning lesion on a self-skin exam
50Patient EducationThere are multiple resources to help educate patients about sun safety and skin cancer prevention, including:American Academy of Dermatology: SPOT Skin Cancer™ initiativeAmerican Cancer Society: Skin Cancer Prevention and Early DetectionThe following slides are adapted from the AAD SPOT Skin Cancer™ program and reflect recent, Board-approved changes to public messages about sun safety:
51Patient Education: SPOT Skin Cancer™ Seek shade when appropriate. Remember that the sun’s rays are strongest between 10 a.m. and 2 p.m. If your shadow appears to be shorter than you are, seek shade.Wear protective clothing, such as a long-sleeved shirt, pants, a wide-brimmed hat, and sunglasses, where possible.Generously apply a broad-spectrum, water-resistant sunscreen with a sun protection factor (SPF) of 30 or more to all exposed skin. “Broad-spectrum” provides protection from both ultraviolet A (UVA) and ultraviolet B (UVB) rays. Reapply approximately every two hours, even on cloudy days, and after swimming or sweating.
52Patient Education: SPOT Skin Cancer™ Use extra caution near water, snow, and sand because they reflect and intensify the damaging rays of the sun, which can increase your chances of sunburn.Avoid tanning beds. Ultraviolet light from the sun and tanning beds can cause skin cancer and wrinkling. If you want to look tan, consider using a self-tanning product or spray, but continue to use sunscreen with it.
53How to perform a skin self-examination Examine your body front and back in the mirror, then look at the right and left sides with your arms raised.Look at the backs of your legs and feet, the spaces between your toes, and the soles of your feet.Examine the back of your neck and scalp with a hand mirror. Part hair for a closer look.Bend elbows and look carefully at forearms, upper underarms, and palms.
54Take Home PointsIndurated erythematous lesions with keratin are SCC until proven otherwise.The diagnosis of SCC is established via shave biopsy.The treatment of SCC is surgical excision. Radiation therapy is a good choice in poor surgical candidates.Actinic keratoses are erythematous papules or thin plaques with scale. They feel rough on palpation but are not indurated.Actinic keratosis is a precancerous lesion that can evolve into squamous cell carcinoma.The treatment for actinic keratoses depends on the number of lesions and the patient’s preference.
55AcknowledgementsThis module was developed by the American Academy of Dermatology Medical Student Core Curriculum Workgroup fromPrimary authors: Amit Garg, MD, FAAD; Lisa Nguyen, MD; Meera Mahalingam, MD.Contributor: Sarah D. Cipriano, MD, MPH.Peer reviewers: Timothy G. Berger, MD, FAAD; Patrick McCleskey, MD, FAAD; Carlos Garcia, MD; Isaac M. Neuhaus, MD, FAAD.Revisions and editing: Sarah D. Cipriano, MD, MPH. Jillian W. Wong. Last revised September 2011.
56ReferencesBerger T, Hong J, Saeed S, Colaco S, Tsang M, Kasper R. The Web- Based Illustrated Clinical Dermatology Glossary. MedEdPORTAL; Available from:Marks R, Rennie G, and Selwood TS. Malignant Transformation of Solar Keratoses to Squamous Cell Carcinoma 1988; 331:Skin Cancer National Cancer Institute at the National Institutes of Health.Wolff K, Johnson RA, and Suurmond R. Fitzpatrick's Color Atlas & Synopsis of Clinical Dermatology. 5th ed. New York: McGraw-Hill, 2005.Wolff K, Goldsmith LA, Katz SL, Gilchrest BA, Paller AS, and Leffel DJ. Fitzpatrick's Dermatology in General Medicine. 7th ed. New York: McGraw-Hill
57Additional ResourcesNguyen L, Mahalingam M, Garg A. Dermatology Clinical Case Modules: 70-Year-Old Man with a Red Crusty Bump on his Right Arm. MedEdPORTAL; ?subid=8055.Nguyen L, Mahalingam M, Garg A. Dermatology Clinical Case Modules: 62-Year-Old Man With a Facial Growth. MedEdPORTAL; ?subid=7751.Nguyen L, Mahalingam M, Garg A. Dermatology Clinical Case Modules: 40-year-old Woman with a Dark Mole. MedEdPORTAL; ?subid=8067.