The Pink Rim Sign: Location of Pink as an Indicator of Melanoma in Dermoscopic Images

Abstract

Background. In dermoscopic images, multiple shades of pink have been described in melanoma without specifying location of these areas within the lesion. Objective. The purpose of this study was to determine the statistics for the presence of centrally and peripherally located pink melanoma and benign melanocytic lesions. Methods. Three observers, untrained in dermoscopy, each retrospectively analyzed 1290 dermoscopic images (296 melanomas (170 in situ and 126 invasive), 994 benign melanocytic nevi) and assessed the presence of any shade of pink in the center and periphery of the lesion. Results. Pink was located in the peripheral region in 14.5% of melanomas and 6.3% of benign melanocytic lesions, yielding an odds ratio of 2.51 (95% CI: 1.7–3.8, P < 0.0001). Central pink was located in 12.8% of melanomas and 21.8% of benign lesions, yielding an odds ratio of 0.462 (95% CI: 0.67, P = 0.204). Pink in melanoma in situ tended to be present throughout the lesion (68% of pink lesions). Pink in invasive melanoma was present in 17% of cases, often presenting as a pink rim. Conclusions. The presence of pink in the periphery or rim of a dermoscopic melanocytic lesion image provides an indication of malignancy. We offer the “pink rim sign” as a clue to the dermoscopic diagnosis of invasive melanoma.

Fuzzy Color Clustering for Melanoma Diagnosis in Dermoscopy Images

“…First, our results confirm results from a previous study that found that white or hypopigmented areas in the outer three deciles of the lesion were needed for the best discrimination of melanoma vs. benign [38]. Second, we have confirmed the clinical impression that colors within the lesion periphery, specifically the outer lesion deciles, are important in describing benign lesions, since a circumferential "hazy border", with coloration intermediate between that of skin and lesion, implies a benign lesion [32] and a "pink rim" is a sign of a melanoma [39]. Third, the patches or clusters of color that matter most are larger than a single pixel but still relatively small, in the single-digit range, as in the "peppering" of early malignancies [40,41].…”

Real‐time supervised detection of pink areas in dermoscopic images of melanoma: importance of color shades, texture and location

“…Data presented in Fig. show that, although pink present throughout the lesion is the most common pattern, pink found in the periphery of the lesion is more discriminatory for melanoma, yielding an odds ratio of 2.51 .…”

“…Pink is also present in benign scalp nevi, often throughout the entire lesion . Pink throughout the entire lesion was found in the majority of both melanoma and benign lesions ; while pink at the rim of the lesion (pink rim sign) was described as a useful feature in detecting melanoma .…”

“…In a previous study , we analyzed 1290 lesions, 296 melanomas (170 in situ lesions; 126 invasive lesions), and 994 benign lesions, with regard to three general locations of pink: peripheral‐only pink (pink in the outer part of the lesion but not in the central part), central only pink (pink in the central part of the lesion but not in the outer part), and pink throughout the lesion (present in both the outer and the central part of the lesion) as shown in Fig. .…”

Newly described signs in dermatology

“…The presence of pink in the periphery or rim of a dermoscopic melanocytic lesion image provides a suspicion of malignancy and is referred to a “pink rim” sign, which is a clue to the dermoscopic diagnosis of invasive melanoma. [ 6 ]…”