Dermoscopic Recognition of Common Non-Melanocytic Lesions and Basal Cell Carcinoma

Conclusions

• Dermoscopy is most useful as a structured two-step process: first decide whether a lesion is melanocytic or non-melanocytic, then apply the appropriate pattern-based clues to narrow the diagnosis.
• Hemorrhage is often recognized by color, peripheral satellite blood spots, and sometimes by scraping or tape-stripping off superficial pigment to reveal blood.
• Hemangiomas and angiokeratomas can look very dark or even black, but lacunae, thrombosis, a delicate white network, and associated vascular patterns usually point to a vascular lesion rather than melanoma.
• Dermatofibromas are suggested by a central white scar-like patch, peripheral pigment network, dotted or looped vessels, and sometimes yellow structures from sebaceous induction, especially on the shoulder and arms.
• Solar lentigines are usually benign when they are sharply demarcated, scalloped, and show faint fingerprint-like pigment network or structureless light-brown areas.
• Facial pigmented lesions with a pseudonetwork and preserved follicular openings can fit solar lentigo, whereas loss of sharp borders, disconnected pigment, and asymmetric follicular pigment raise concern for melanoma in situ.
• Seborrheic keratoses are commonly identified by milia-like cysts, comedo-like openings, and brain-like or fat-finger network structures, even when they appear very dark clinically.
• Basal cell carcinoma is the most clinically important and useful dermoscopic diagnosis in this topic because dermoscopy markedly improves detection of a very common skin cancer.
• Non-pigmented basal cell carcinoma is suggested by translucency, white shiny structures, prominent arborizing or short fine vessels, shallow ulceration, and a pink-red background.
• Pigmented basal cell carcinoma is diagnosed by adding blue-gray nests or globules and pigmented islands to the non-pigmented BCC pattern, which can otherwise mimic melanoma.
• No single dermoscopic feature is pathognomonic, so interpretation must be made in the context of the patient’s background skin damage, history, and overall lesion pattern.
• Several benign and inflammatory lesions, including scars, lichenoid keratosis, lichen planus, dermatofibroma, and even some neoplasms, can simulate basal cell carcinoma, making pattern recognition and clinicopathologic correlation essential.