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General Instructions
For each case, there is a short history along with a clinical and an unmarked dermoscopic image.
Study the unmarked dermoscopic image and try to identify the global and local dermoscopic features.
Make your diagnosis.
Next, turn the page and the dermoscopic image will be presented again, this time marked with all the salient dermoscopic findings.
On the same page you will also find the diagnosis along with a detailed discussion and a few pearls for your review.
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CASE 1 HISTORY
A 76-year-old woman has a slowly growing lesion on her left cheek.
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DERMOSCOPIC CRITERIA
Arborizing vessels (black arrows)
Bluish-white color (black stars)
Pigmentation (yellow arrows)
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DIAGNOSIS:
Pigmented Basal Cell Carcinoma
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This is a classic pigmented basal cell carcinoma. As such, it has in-focus, thick- and thin-walled, arborizing (tree-like branching) vessels that fill the lesion, along with spotty pigmentation.
For the expert dermoscopist, this is a “blink” diagnosis.
However, arborizing vessels are highly suggestive of basal cell carcinoma, they may also be seen in melanoma, nevi, neurofibromas, sebaceous gland hyperplasia, Merkel cell carcinoma, scar tissue and on sun damaged skin.
More concerning here is the bluish-white color, which itself is frequently seen in melanoma and thus presents a red flag for concern. Remember, “If there’s blue, they might sue!”
Thus, for the novice dermoscopist, it is best to follow the 2-step algorithm to evaluate this lesion.
First, determine if the lesion is melanocytic. Here, there are no criteria associated with a melanocytic lesion (eg, pigment network, brown dots and globules, homogeneous blue color).
Knowing the lesion is not melanocytic, next determine if there are other criteria present to indicate a seborrheic keratosis, basal cell carcinoma, hemangioma, or dermatofibroma.
There are no criteria for a seborrheic keratosis (milia-like cysts, pseudofollicular openings, fissures and ridges, “fat fingers,” hairpin vessels).
There are no criteria for a hemangioma (lacunae, fibrous septae).
There are no criteria for a dermatofibroma (central white patch, peripheral pigment network).
There are, however, the classic criteria for a pigmented basal cell carcinoma, including the in-focus arborizing vessels and pigmentation.
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There are many dermoscopic presentations of basal cell carcinoma.
There will be times when the differentiation of a basal cell carcinoma from a melanoma is problematic.
An important clue to remember in such situations is that you will never see pigment network in a basal cell carcinoma.
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