A Review of Dermoscopy Techniques With Michelle Tarbox, MD

In a hands-on Winter Clinical workshop, Michelle Tarbox, MD, walked through practical ways to get more out of every dermoscopic exam, focusing less on memorizing patterns and more on how and when to use specific techniques.

She revisits one of the most common pitfalls in dermoscopy: relying on a single viewing mode. By deliberately toggling between polarized and non-polarized light, clinicians can surface different diagnostic clues—using non-polarized dermoscopy to better visualize milia-like cysts and comedo-like openings, and polarized dermoscopy to highlight vessels and chrysalis structures.

Dr. Tarbox also discusses contact versus non-contact dermoscopy, emphasizing that each has distinct clinical advantages depending on what you’re evaluating. For suspected actinic keratoses on the head and neck—particularly pigmented AKs that can mimic lentigo maligna—she recommends starting with dry, non-polarized dermoscopy to identify characteristic surface scale. In contrast, pigmented lesions benefit from contact or polarized dermoscopy, which allows clearer visualization of deeper structures across both benign and malignant neoplasms.

Lastly, she clarifies an important diagnostic distinction: chrysalis structures are only visible with polarized light, while a negative pigment network represents a separate finding that serves as a warning signal for potential melanoma. Taken together, these are small technical adjustments with meaningful clinical impact and reminders that dermoscopy works best when approached deliberately, with flexibility and context.