Picture Quizzes –Benign and cancerous skin lesions

18. Malignant melanoma usually presents with skin lesions that are changing in configuration (asymmetric, irregular border), color (red, white, and blue tones in a brown or black lesion), size (diameter >6 mm) or configuration (elevated surface). Lesions may be symptomatic (itching, bleeding, or ulcerating). Recognition is crucial because if detected early, melanoma may be cured with surgical excision.

19. Melanocytic nevi (not congenital) are common, benign, and skin-colored to brown or black, seen most commonly in lighter-skinned individuals. They are well circumscribed with symmetric proliferations. Nevi on the palms and soles, nail beds, and conjunctiva are more common in dark-skinned people.

20. Dysplastic melanocytic nevi are a variant of melanocytic nevi. They typically present as flat, irregularly pigmented and shaped macules or papules. They may exhibit fried egg–like appearance, with a central papular zone and a surrounding macular area. Individuals with large numbers of nevi and a familial history of multiple nevi or melanoma (dysplastic nevus syndrome) have a high risk of developing melanoma and require close clinical monitoring.

21.  Blue nevi are a variant of melanocytic nevi. They are typically heavily pigmented, well-circumscribed, homogenous, gray or black papules. They typically occur on the distal extremities or scalp.  

22. Cutaneous squamous cell carcinoma arises on sun-exposed skin of middle-aged and elderly individuals. The typical initial presentation of cutaneous SCC is an abnormal papule, plaque, or nodule with variable degrees of scale, crust, or ulceration. About 70% of cutaneous SCCs occur on the head and neck, most frequently involving the lower lip, ear and periauricular region, forehead, and scalp.

23. Cutaneous horns are exophytic, hyperkeratotic, yellow to brown papules that project in a conical fashion to resemble a horn. They occur most frequently in sun-exposed areas of older, fair-skinned individuals. Cutaneous horns represent an underlying skin disorder—most commonly actinic keratoses, seborrheic keratoses, and warts. Squamous cell carcinoma is found in up to 20% of cases. Because of the potential for malignancy at the base of a cutaneous horn, a biopsy is recommended.

24. Actinic keratoses are rough or scaly papules and plaques. These lesions have potential for malignant transformation to invasive squamous cell carcinoma. They arise more frequently on sun-exposed areas (face, ears, neck scalp, hands, legs, and upper trunk) of fair-skinned individuals, particularly if there is a history of chronic sun exposure, outdoor professions or hobbies, and immunosuppression.  

25. Solar lentigos are common, sharply circumscribed hyperpigmented macules of variable size, surrounded by normal-appearing skin. They are seen on sun-exposed areas, most commonly the face, arms, dorsal hands, and upper trunk. Older lesions are often darker, and coalesce to form larger patches. Multiple solar lentigines identify individuals at higher risk of developing cutaneous malignancies. They may be treated for cosmetic reasons.

26. Keratoacanthomas are rapidly growing dome-shaped nodules with a smooth shiny surface and characteristic central keratin plug or ulceration. After a rapid growth phase of a few weeks, they may become static or undergo slow spontaneous involution. Most lesions occur on sun-exposed areas of the face, neck, and upper extremities. Keratoacanthomas may represent very well-differentiated squamous cell carcinomas. Excision is often advocated due to rare risk of progression to invasive or metastatic carcinoma.