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. 2025 Jul;31(7):e70206.
doi: 10.1111/srt.70206.

Seborrheic Keratosis-Like Melanoma: Novel Insights Into Clinical, Dermoscopic, and Reflectance Confocal Microscopy Diagnosis of an Atypical Melanoma Variant

Federico Venturi  1   2 , Stephano Cedirian  1   2 , Giulia Veronesi  1   2 , Biagio Scotti  1   2 , Carlotta Baraldi  1 , Emi Dika  1   2
Affiliations

Seborrheic Keratosis-Like Melanoma: Novel Insights Into Clinical, Dermoscopic, and Reflectance Confocal Microscopy Diagnosis of an Atypical Melanoma Variant

Federico Venturi et al. Skin Res Technol. 2025 Jul.

Abstract

Background: Studies have found that few lesions clinically diagnosed as seborrheic keratosis (SK) revealed Cutaneous melanoma (CM) on histopathology. When CM mimics SK, they are defined as seborrheic keratosis-like melanoma (SKLM), and a delayed diagnosis and treatment can occur.

Methods: We conducted a retrospective descriptive, monocentric study of the epidemiological, clinical, videodermoscopy (VDS), and reflectance confocal microscopy (RCM) characteristics of histopathologically proven SKLM diagnosed between 2018 and 2024.

Results: The study population consisted of 60 patients: 44 males (73.3%) and 16 females (26.7%) with lesions located in 73.3% of cases on the trunk. Concerning histological type, superficial spreading melanoma was the more frequent (86.7%). More than 50% of tumors had a Breslow thickness <0.8 mm. The findings from the VDS examination using the revised Argenziano Seven Point Checklist revealed that 100% of cases presented at least one dermoscopic melanoma-specific criterion and, for this reason, had an indication for surgical excision. Typical RCM patterns associated with melanoma diagnosis were observed, including irregular honeycomb/cobblestone pattern (82.1%), irregular DEJ nests (78.6%), dermal inflammation (53.6%), irregular dermal nests (53.6%), dendritic cells in sheets/tangled lines (50%), and atypical round cells (39.3%).

Conclusion: Our study provides valuable insights into the dermoscopic, RCM, and histological features of SKLM based on the largest monocentric cohort. The distinctive dermoscopic patterns, along with the confocal features, aid in the differentiation from other pigmented lesions.

Keywords: cutaneous melanoma; dermoscopy; reflectance confocal microscopy; seborrheic keratosis.

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Conflict of interest statement

The authors declare no conflicts of interest.

Figures

FIGURE 1
FIGURE 1
(A, B, C) Clinical, dermoscopic, and confocal presentation of SKLM on the back of a 55‐year‐old patient. At clinical examination, SKLM presented as a hyperpigmented, hyperkeratotic nodule (A). Dermoscopic examination revealed an irregular pigmentation, blue‐white veil, and irregular streaks (B). Reflectance confocal microscopy of SKLM displayed irregular DEJ nests (red circle), dendritic cells (red box), and atypical round cells (arrows) (C).
FIGURE 2
FIGURE 2
(A, B, C) Clinical, dermoscopic, and confocal presentation of SKLM on the scalp of a 68‐year‐old patient. At clinical examination, SKLM presented as a flat pigmented macule with irregular border and perifollicular pigmentation (A). Dermoscopic examination of the lower part of the lesion revealed asymmetry of structures, atypical pigmentary network, atypical globules and irregular dots, areas with irregular homogeneous pigmentation and comedo‐like openings (B). Reflectance confocal microscopy of SKLM displayed the epidermal disarray with atypical cells surrounding the follicular openings (C).
See this image and copyright information in PMC

References

    1. Moscarella E., Brancaccio G., Briatico G., Ronchi A., Piana S., and Argenziano G., “Differential Diagnosis and Management on Seborrheic Keratosis in Elderly Patients,” Clinical, Cosmetic and Investigational Dermatology 14 (2021): 395–406, 10.2147/CCID.S267246. - DOI - PMC - PubMed
    1. Zhai H., Dika E., Goldovsky M., and Maibach H. I., “Tape‐Stripping Method in Man: Comparison of Evaporimetric Methods,” Skin Research and Technology: Official Journal of International Society for Bioengineering and the Skin (ISBS) [And] International Society for Digital Imaging of Skin (ISDIS) [And] International Society for Skin Imaging (ISSI) 13, no. 2 (2007): 207–210, 10.1111/j.1600-0846.2007.00218.x. - DOI - PubMed
    1. Farnetani F., Pedroni G., Lippolis N., et al., “Facial Seborrheic Keratosis With Unusual Dermoscopic Patterns Can be Differentiated From Other Skin Malignancies by in Vivo Reflectance Confocal Microscopy,” Journal of the European Academy of Dermatology and Venereology 35, no. 11 (2021): e784–e787, 10.1111/jdv.17470. - DOI - PubMed
    1. De Giorgi V., Silvestri F., Savarese I., et al., “Porocarcinoma: An Epidemiological, Clinical, and Dermoscopic 20‐Year Study,” International Journal of Dermatology 61, no. 9 (2022): 1098–1105, 10.1111/ijd.16129. - DOI - PubMed
    1. Braga J. C. T., Scope A., Klaz I., Mecca P., Spencer P., and Marghoob A. A., “Melanoma Mimicking Seborrheic Keratosis: An Error of Perception Precluding Correct Dermoscopic Diagnosis,” Journal of the American Academy of Dermatology 58, no. 5 (2008): 875–880, 10.1016/j.jaad.2007.12.011. - DOI - PubMed