The diagnostic value and histologic correlate of distinct patterns of shiny white streaks for the diagnosis of melanoma: A retrospective, case-control study

Abstract

Background: Shiny white streaks (SWSs) are best visualized with polarized dermoscopy and correlate with dermal fibroplasia histopathologically. SWSs have been described at higher frequencies in melanomas than in benign nevi.

Objective: We assessed the diagnostic value of different patterns of SWSs and their histologic correlate in melanocytic lesions.

Methods: Polarized dermoscopic images of 1507 histopathologically diagnosed melanocytic neoplasms were analyzed for presence and pattern of SWSs. Histology was also reviewed for correlation.

Results: Among 1507 melanocytic neoplasms, SWSs were observed in 31 of 144 melanomas (22%) and 22 of 1363 benign neoplasms (1.6%) (P < .001). The sensitivity and specificity of SWSs for melanoma were 22% and 98%, respectively. Diffuse SWSs exhibited the greatest diagnostic value for melanoma, with sensitivity of 11.8% and specificity of 99.5%. Focal central and peripheral SWSs were comparable in diagnostic significance. The presence of SWSs was highly uncommon in dysplastic nevi, whereas in certain benign subgroups of nevi such as Spitz nevi and atypical genital special site nevi, SWSs were not uncommon. Diffuse SWSs correlated with greater breadth of deep fibroplasia than focal SWSs (P = .009), and SWSs correlated with greater Breslow depth among melanomas (P = .007).

Limitations: This study was retrospective.

Conclusion: Polarized dermoscopy is a valuable diagnostic tool in the identification of SWSs, a feature that is highly specific for melanoma.

Keywords: crystalline/chrysalis structures; dermoscopy; histology; melanoma; nevi; pigmented skin lesions; polarized dermoscopy; shiny white streaks.

Fig 1.

A, Superficial spreading melanoma from the right thigh of a 48-year-old man with a Breslow depth of 1.1 mm. The lesion has diffuse shiny white streaks throughout, a blue-gray veil, and peripheral brown structureless areas. B, At ×100 magnification one can appreciate confluent junctional nests of highly atypical melanocytes effacing the epidermis and extending into the dermis. There is ribbon-like thickening of collagen strands in the reticular dermis directly below the tumor. At ×200 magnification (inset) one can see the contrast of the thick ribbon-like collagen in the superficial reticular dermis compared with the surrounding collagen.

Fig 2.

A, Superficial spreading melanoma from the left upper back of a 30-year-old woman with a Breslow depth of 0.34 mm. This lesion shows asymmetric streaks all along the superior border, atypical dots and globules, and an area with milky red and focal shiny white streaks in the inferior portion. B, At ×100 magnification, highly atypical melanocytes arranged in single pagetoid cells and nests are seen in the epidermis. The papillary dermis is focally expanded by markedly thickened collagen that also extends into the superficial reticular dermis.

Fig 3.

A, Atypical compound nevus of vulvar skin from a 42-year-old woman. The dermoscopic images show peripheral areas with reticulation and a central structureless area with vascular blush with diffuse shiny white streaks throughout. B, At ×20 magnification one can see a broad compound melanocytic neoplasm with an extensive junctional component that broadly involves both lateral margins of the figure. Inset 1 at ×100 magnification (left) shows an area of dermal melanocytes with noticeable surrounding host stromal fibroplasia, which is the histologic correlate of shiny white streaks seen on dermoscopy. Inset 2 (right) shows ×200 magnification of the junctional component, which had prominent lentiginous growth of melanocytes as well as areas with suprabasal movement.

Fig 4.

A, A typical Spitz tumor from the left forearm of 13-year-old boy. The lesion has an inverse pigment network, milky red areas, and shiny white streaks throughout the center of the lesion. B, At ×100 and ×200 magnification (inset) there is a compound spitzoid melanocytic neoplasm with overlying epidermal hyperplasia. There are thick ribbon-like bands of collagen entrapping dermal nests in the papillary and reticular dermis.