JD Neoplasms of the Skin PDF

1/28/25 Neoplasms of the Skin Darren Kempton, MD, DPT UNM Dept of Dermatology 1 After completion of this topic, students should be able to: 1. Describe the clinical presentation and histopathologic findings of beni...

1/28/25 Neoplasms of the Skin Darren Kempton, MD, DPT UNM Dept of Dermatology 1 After completion of this topic, students should be able to: 1. Describe the clinical presentation and histopathologic findings of benign skin growths of the following cellular origins: Keratinocytes, Melanocytes, Blood vessels (examples nevi, seborrheic keratosis, pyogenic granuloma) 2. Describe the clinical presentation, precursor lesions (example actinic keratosis), risk factors and hereditary cancer syndromes that lead to skin cancers (examples basal cell carcinoma, squamous cell carcinoma, melanoma) 3. Explain the role of Ultraviolet light and other environmental factors in development of various skin cancers. 2 3 1  1/28/25 Which of the following is true of this lesion? A: The morphology is concerning and the lesion should be biopsied. B: This lesion commonly occurs in children. C: This is a malignant proliferation of melanocytes. D: This is a common, benign proliferation of keratinocytes. E: A viral process is the underlying cause of this lesion. 4 Seborrheic keratosis is a common benign neoplasm of older persons. 5 Clinical description: Flat-topped to exophytic papules “warty” “stuck-on” Range from light tan/pink to dark brown/gray, but no true pigment pattern Very common in older individuals 6 2  1/28/25 7 PICTURE OF SK 8 Seborrheic keratosis is a benign proliferation of keratinocytes “String sign” 9 3  1/28/25 Seborrheic keratoses have prominent horn cysts. 10 The keratinocytes lack atypia and mitoses. 11 12 4  1/28/25 Which of the following lesions is most likely a benign proliferation of melanocytes? 13 Clinical characteristics of benign pigmented lesions Symmetric Distinct Border Homogenous color (Smaller than pencil eraser in Adults) Stable/unchanging 14 Which of the following lesions is most likely a benign proliferation of melanocytes? 15 5  1/28/25 Nevus = “mole” nevus /ne·vus/ (ne´vus) pl. ne´vi [L.] derived from the Latin word naevus meaning birthmark Any of various congenital or acquired lesions of the skin or oral mucosa that are usually pigmented and raised and may include epidermal, melanocytic, connective, or other types of tissue. 16 On histology, melanocytic nevi are described by which portion of the skin are involved: epidermis (junctional nevus), epidermis and dermis (compound), or only dermis (intradermal melanocytic nevus) 17 Compound melanocytic nevus 18 6  1/28/25 Intradermal melanocytic nevus 19 A benign melanocytic nevus has the following characteristics: Symmetric lesion Melanocytes mature with descent – Superficial cells larger, pigmented, well-nested – Deeper cells smaller, nonpigmented, less nested Melanocytes show no or minimal cytologic atypia Mitotic activity rarely present 20 21 7  1/28/25 22 23 A patient presents with multiple pigmented lesions. Which of the following pigmented lesions is of most concern to you? 24 8  1/28/25 25 26 Multiple subtypes of melanoma Superficial spreading Nodular Superficial spreading melanoma is the most common subtype accounting for almost 70% of all cutaneous melanomas. It can occur anywhere on the body but has a predilection for lower leg in females and upper back in males. 27 9  1/28/25 Multiple subtypes of melanoma Superficial spreading Nodular Superficial spreading melanoma is the most common subtype accounting for almost 70% of all cutaneous melanomas. It can occur anywhere on the body but has a predilection for lower leg in females and upper back in males. 28 Multiple subtypes of melanoma Acral lentiginous Lentigo maligna Acral lentiginous melanoma (ALM) makes up majority of melanomas arising in dark-skinned races 29 30 10  1/28/25 Pagetoid spread: upward intraepidermal spread of melanocytes 31 32 Histopathologic features of nevus vs. melanoma Nevus Melanoma Symmetric Asymmetric Matures with depth Does not mature with depth Rare or absent mitoses Mitoses present Absent cytologic atypia Cytologic atypia Absent pagetoid spread Prominent pagetoid spread 33 11  1/28/25 Which of the following histopathologic features of melanoma is the most important for prognosis? A: Presence or absence of ulceration B: mitotic rate C: margin status D: depth of invasion E: Lymphovascular invasion 34 Which of the following histopathologic features of melanoma is the most important for prognosis? A: Presence or absence of ulceration B: mitotic rate C: margin status D: depth of invasion E: Lymphovascular invasion 35 36 12  1/28/25 37 BRAF V600E mutation is common in melanoma. 38 BRAF kinase inhibitors, such as Vemurafenib or dabrafenib, may benefit patients with metastatic or unresectable melanoma. 39 13  1/28/25 In small groups, discuss how you would describe each of these lesions: 40 Biopsy of which of the following lesions would most likely reveal the most commonly occurring type of skin cancer? 41 Clinical features of basal cell carcinoma Sun exposed skin “Pearly” or shiny Papules with substance Telangectasias Erosion/ulceration Bleed easily with minimal trauma 42 14  1/28/25 43 Which of the following histologic pictures represents a basal cell carcinoma? 44 Basal cell carcinoma is characterized by nests of basaloid cells with: 46 15  1/28/25 47 48 Basal cell carcinoma is the most commonly occurring skin cancer Locally aggressive but rarely metastasize Pathogenesis related to sun exposure Genetic factors may also play a role “Pigmented” may look gray, blue or almost black 49 16  1/28/25 A 76 year old farmer from the North Valley with significant history of sun exposure presents with extensive small rough erythematous papules 50 51 Biopsy of one of these lesions shows the following: 52 17  1/28/25 Actinic keratosis “SPA” 53 54 Which of the following is true of an actinic keratosis? A: If left untreated, approximately 10% of actinic keratoses would gradually transform into squamous cell carcinoma. B: If left untreated, close to 100% of actinic keratoses would gradually transform into squamous cell carcinoma. C: This is a premalignant lesion caused by sun exposure. D: A&C E: B&C 55 18  1/28/25 Actinic keratosis: a premalignant lesion related to chronic sun exposure ~10% will progress to squamous cell carcinoma if untreated 56 At the next appointment, the patient presents with two new lesions. In small groups, discuss how you would describe these lesions. Are these likely to be benign or malignant? 57 58 19  1/28/25 59 SCCIS MICROSCOPIC: Atypical keratinocytes- full thickness involvement of the epidermis Mitoses throughout epidermis 60 SCCIS (Bowens) Clinical Characteristics Relatively well-defined, localized Slightly scaly Thin (not indurated) Pink plaque No erosion, ulceration or marked thickening 61 20  1/28/25 63 64 Invasive SCC: microscopic Atypical keratinocytic proliferation Invades into dermis/subcutis Prominent keratin pearls 65 21  1/28/25 SQUAMOUS CELL CARCINOMA Second most common skin cancer Red papule, nodule, or plaque Sun damaged areas, scars, irradiated or chronically infected sites, lichen sclerosis, lichen planus, discoid lupus, xeroderma pigmentosum, organ transplant recipients More likely to metastasize than bcc 67 SCC Clinical Characteristics Infiltrative to indurated papule to plaque Pink to red Scaly Often ulcerated +/- hemorrhagic crusting 68 69 22  1/28/25 Pathogenesis of Squamous cell carcinoma Most commonly exposure to UV light with subsequent DNA damage Increased risk in immunosuppressed (transplant pts), XP 70 Etiology of skin cancer 71 Types of UV radiation UVB is prominent in sunBurn UVA is prominent in tAnning and photoAging 72 23  1/28/25 UVB radiation can directly damage DNA within keratinocytes. 73 UVB radiation can directly damage DNA within keratinocytes. 74 Xeroderma pigmentosum is a rare, autosomal recessive, genodermatosis characterized by deficient DNA repair. 75 24  1/28/25 76 Nevoid Basal Cell Carcinoma Syndrome AKA Gorlins PTCH mutation Develop extensive BCCs Need to avoid radiation Other features: – Odontogenic keratocysts – Skeletal abnormalities 77 Dysplastic nevus syndrome Also known as Atypical Mole Syndrome, Familial atypical multiple mole- melanoma syndrome, familial melanoma syndrome Cutaneous condition in certain families characterized by unusual nevi and multiple inherited melanomas Some families have mutations in CDKN2A genes 78 25  1/28/25 Vascular tumors of skin 79 Pyogenic Granuloma (AKA Lobular capillary hemangioma) Common benign vascular tumors Overgrowth of granulation tissue – Following minor trauma – Foreign body Location – Usually face or extremity Description – Solitary bright red, soft nodules – Pedunculated – 5-6mm – Friable surface Treatment – Excision – Electrodessication of the “feeder” vessels 80 81 26  1/28/25 Infantile Hemangiomas Infantile Hemangiomas – Most common vascular tumor of infancy 10% – More common in Caucasians Females Premature infants Placental abnormalities – Location >50% head and neck 25% trunk Rest on extremities – Timing Several days to weeks after delivery 82 Hemangiomas Infantile Hemangiomas – Description Reddening or bluish discoloration of skin Bright red nodule or plaque with elevation – Types Superficial (epidermal) – “Strawberry” or bright red – Well demarcated – Elevated – Soft compressible – Few mm to 5cm Deep (dermis or subq fat) – Bluish hue – Indistinct borders – Doughy consistency – Enlarge when dependent Mixed – Most hemangiomas 84 Hemangiomas Infantile Hemangiomas – Course Grow and peak by 6-9 months Stabilization Involution – 10% per year – Graying out of surface 40% with residual skin changes – Telangiectasias – Fibro-fatty tissue 85 27  1/28/25 Cherry angioma Definition Benign vascular neoplasm in adults Epidemiology Middle-aged adults and the elderly; increasing prevalence with age Very common No gender predilection Presentation Trunk and upper arms Usually multiple, small, often dome-shaped, discrete, deep red (hence the appellation “cherry”) papules Usually asymptomatic, can bleed secondary to trauma Mucosa spared Prognosis and treatment May be confused with a pigmented lesion and, hence, excised for diagnostic purposes Usually removed for cosmetic reasons or due to traumatic bleeding 86 Kaposi sarcoma 87 88 28  1/28/25 89 HHV-8 90 Angiosarcoma 91 29  1/28/25 Seborrheic keratosis, in summary “Stuck on” exophytic brown papules Common benign keratinocytic proliferation On biopsy, has horn cysts, string sign, lacks atypia 92 Nevus, In Summary: Benign proliferation of melanocytes, “mole” Junctional, intradermal, or compound Symmetric, distinct border, small, homogenous color 93 BCC In Summary: Clinical: Pink, pearly papule, commonly with telangiectasias and rolled borders, ulceration Pathology: basaloid islands with peripheral palisading, mucin, clefting 94 30  1/28/25 Melanoma summary ABCDEs clinical presentation Different subtypes On pathology, pagetoid spread, atypia, mitoses Depth of invasion important to prognosis! Role of BRAF inhibitors 95 After completion of this topic, students should be able to: 1. Describe the clinical presentation and histopathologic findings of benign skin growths of the following cellular origins: Squamous cell, Melanocytes (examples nevi, seborrheic keratosis) 2. Describe the clinical presentation, precursor lesions (example actinic keratosis), risk factors and hereditary cancer syndromes that lead to skin cancers (examples basal cell carcinoma, squamous cell carcinoma, melanoma) 3. Explain the role of Ultraviolet light and other environmental factors in development of various skin cancers. 96 31