Snapshot A 70-year-old man presents to the dermatologist’s office for his annual skin exam. He complains of a large pink lesion on his cheek that oozes and bleeds. It never seemed to heal properly. He is concerned, because he knows that he should have used more sunscreen throughout his life. Introduction Invasive primary skin malignancy arising from keratinocytes of skin or mucosa Epidemiology common in fair-skinned individuals common in elderly patients 2nd most common form of skin cancer (first is basal cell carcinoma ) risk factors sun exposure actinic keratosis immunosuppression (similar to treatment after organ transplant) arsenic exposure old scars or burns xeroderma pigmentosum ionizing radiation Pathogenesis damage to keratinocytes metastases are rare Keratoacanthoma is a variant of low-grade squamous cell carcinoma grows rapidly and regresses spontaneously Presentation Symptoms typically asymptomatic Physical exam red, poorly defined base with adherent yellow or white scale smooth, dull, red, dome-shaped nodule with ulcerated center frequently on sun-exposed areas face, neck, hands, ears common on lower lips lesions often against a background of sun-damaged skin Evaluation Diagnosis by skin biopsy atypical keratinocytes and malignant cells invasion into dermis keratin “pearls” on histology Differential Diagnosis Actinic keratosis Actinic cheilitis Treatment Surgical wide local excision with negative margins Prognosis, Prevention, and Complications Prognosis if treated, very excellent prognosis Prevention sun avoidance sunscreen use
QUESTIONS 1 of 7 1 2 3 4 5 6 7 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.ON.14.51) A 71-year-old man presents to his primary care physician with the lesion seen in Figure A. He states that it has been present for several months. He has no significant past medical history and is a retired construction worker. What would be the expected pathology on biopsy? Tested Concept QID: 104262 FIGURES: A Type & Select Correct Answer 1 Palisading basal cells 19% (6/32) 2 Keratin pearls 47% (15/32) 3 S-100 postive staining cells 9% (3/32) 4 Parakeratosis 12% (4/32) 5 Cowdry inclusions 12% (4/32) M 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.ON.14.57) A 62-year-old man presents to your office for evaluation of a chronic ulcer on the plantar aspect of his right foot. He has a history of peripheral vascular disease and poorly-controlled diabetes mellitus. He states that he has had this ulcer for years, but that it seems to be growing. On examination of his right foot you note the heaped up edges surrounding the ulcer (Figure A). A wedge biopsy reveals irregular masses of anaplastic epidermal cells proliferating down to the dermis and the pathologist reports "keratin pearls". What is the diagnosis? Tested Concept QID: 106379 FIGURES: A Type & Select Correct Answer 1 Melanoma 1% (2/152) 2 Squamous cell carcinoma 84% (127/152) 3 Basal cell carcinoma 8% (12/152) 4 Osteomyelitis 3% (4/152) 5 Plantar fasciitis 3% (5/152) M 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept (M1.ON.13.1) A 58-year-old lifeguard develops squamous cell carcinoma of the skin on his forehead. Which of the following most likely preceded the development of this carcinoma? Tested Concept QID: 101308 Type & Select Correct Answer 1 Hamartomatous lesion of sebaceous glands 3% (5/164) 2 Dry, scaly, hyperkeratotic papule 66% (109/164) 3 A single, large pink patch 5% (8/164) 4 Dermatophyte infection 0% (0/164) 5 UVC exposure 25% (41/164) M 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept