Glowing in the dark: case report of a clue-poor melanoma unmasked by polarized dermatoscopy

• Main Authors: Yoon K. Cohen (Author), David J. Elpern (Author), Dean Wolpowitz (Author), Cliff Rosendahl (Author)
• Format: Book
• Published: Mattioli1885, 2014-01-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.5826/dpc.0401a14; 2160-9381
• Keywords: melanoma; nevus; congenital-type nevus; polarized dermoscopy; polarized dermatoscopy; dermatopathology; Dermatology; RL1-803
• Source: Dermatology Practical & Conceptual (2014)

We report a case of a melanoma arising in a congenital-type compound nevus, which was excised because it was observed by both the patient and the treating dermatologist to have changed. Because the lesion was routinely photo-documented with both polarized and non-polarized dermatoscopy images prior to excision, these images were available for subsequent examination. Matched images are presented in what appears to be unique in the published literature: polarizing-specific white lines are identified as a compelling clue to the diagnosis of melanoma in a lesion that contains no clues apparent in the non-polarized image. Dermatopathology images reveal that the melanoma is arising in conjunction with a congenital type nevus. As expected, dermatoscopic polarizing-specific white lines are evident on the melanoma but not the nevus, and while a possible explanation is discussed, this remains speculative.