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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.



This 88-year-old woman has a biopsy-proven basal cell carcinoma under a dark plaque. Clinically, both lesions seem to be connected.


  • Round follicular openings (yellow arrows)

  • Asymmetrical follicular pigmentation (white arrows)

  • Rhomboid structures (yellow box)

  • Irregular blotch with follicular openings (white box)

  • Irregular blotch without follicular openings (stars)

  • Irregular dots and globules (yellow circles)

  • Milky-red areas (black arrows)


Lentigo Maligna Melanoma


  • Asymmetrical follicular pigmentation, rhomboid structures, annular-granular structures, and circle within a circle are the main criteria associated with melanoma on the face.

  • Asymmetrical follicular pigmentation can also be seen in pigmented actinic keratosis and pigmented Bowen disease.

  • The first step in the progression of melanoma on the face is represented by asymmetrical follicular pigmentation.

  • The follicular openings should not be confused with milia-like cysts seen in seborrheic keratosis.

  • The next step in the progression of melanoma on the face is the formation of rhomboid structures.

  • True rhomboid forms (parallelogram with unequal angles and sides) are not necessary to identify.

  • Any pigmented thickening that completely surrounds follicular openings should be considered rhomboid structures.

  • The irregular black blotch with follicular openings is the first sign of dermal invasion (lentigo maligna melanoma).

  • The irregular black blotch without follicular openings represents complete obliteration of follicular openings, indicating further dermal invasion.


  • This is a collision tumor, representing a basal cell carcinoma and melanoma.

  • The diagnosis of melanoma on the face is not always this easy.

  • It is essential to learn the definitions of the 4 main criteria associated with melanoma on the face and be able to recognize them.

  • Dermoscopy is essential to help make the diagnosis in most cases of early lentigo maligna and offers patients their best chance for survival.



This lesion had been ignored for many years. Itch was the reason the patient finally went to see his family physician, who referred him to a dermatologist for evaluation.

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