{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T09:41:45Z","timestamp":1784886105666,"version":"3.55.0"},"reference-count":46,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T00:00:00Z","timestamp":1769731200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cancers"],"abstract":"<jats:p>Introduction: Subungual squamous cell carcinoma is a rare malignancy of the nail unit that is frequently misdiagnosed as benign nail disease, leading to prolonged diagnostic delays and sometimes invasive spread. Objective: To synthesize the dermoscopic features of histologically confirmed subungual squamous cell carcinoma and to compare patterns between invasive and in situ disease. Methods: We performed a systematic review and meta-analysis (PROSPERO CRD42023470387) following PRISMA and MOOSE guidance. PubMed, Scopus and Cochrane CENTRAL were searched. Extracted data included study design, lesion counts, histologic subtype and specific dermoscopic signs. Random-effects meta-analysis (DerSimonian\u2013Laird with Freeman\u2013Tukey transformation) produced pooled prevalences with 95% confidence intervals. Between-study heterogeneity was assessed with Cochran\u2019s Q and I2. We used subgroup and meta-regression analyses to explore the influence of histologic subtype, sample size and publication year. When the data allowed, diagnostic odds ratios were calculated versus common benign mimickers. Results: Twenty studies comprising 121 lesions (96 invasive, 25 in situ) were included. In invasive lesions, the most common dermoscopic findings were subungual hyperkeratosis (pooled prevalence 89%; 95% CI 78\u201397; I2 = 0%), onycholysis (85%; 75\u201393; I2 = 28%), irregular borders (72%; 50\u201390; I2 = 42%), and splinter hemorrhages (52%; 40\u201365; I2 = 36%). In situ lesions more often presented with melanonychia (89%) and showed lower rates of hyperkeratosis (50%). Meta-regression identified histologic subtype as a significant predictor of feature prevalence (p &lt; 0.01). Key comparative performance estimates included a diagnostic odds ratio of 12.6 (95% CI 8.3\u201319.1) for polymorphous vessels distinguishing squamous cell carcinoma from warts and 6.8 (95% CI 3.2\u201314.5) for hyperkeratosis versus onychomycosis. Conclusions: Dermoscopy reliably identifies features, particularly hyperkeratosis, onycholysis, irregular margins and hemorrhagic spots, that are common in invasive subungual squamous cell carcinoma; in situ disease more commonly presents with pigmentary changes. Recognition of these signs should lower the threshold for biopsy of suspicious single-digit nail lesions and may facilitate earlier diagnosis and treatment.<\/jats:p>","DOI":"10.3390\/cancers18030446","type":"journal-article","created":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T11:09:22Z","timestamp":1769771362000},"page":"446","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Dermoscopy of Subungual Squamous Cell Carcinoma: A Systematic Review"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2329-6863","authenticated-orcid":false,"given":"Ewelina","family":"Mazur","sequence":"first","affiliation":[{"name":"Department of Dermatology, Faculty of Medicine, University of Rzesz\u00f3w, 35-959 Rzeszow, Poland"},{"name":"Doctoral School, University of Rzeszow, 35-959 Rzeszow, Poland"},{"name":"Second Department of Dermatology and Venerology, Aristotle University School of Medicine, Papageorgiou Hospital, 546 43 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3268-012X","authenticated-orcid":false,"given":"Dominika","family":"Kwiatkowska","sequence":"additional","affiliation":[{"name":"Department of Dermatology, Faculty of Medicine, University of Rzesz\u00f3w, 35-959 Rzeszow, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Myrto","family":"Trakatelli","sequence":"additional","affiliation":[{"name":"Second Department of Dermatology and Venerology, Aristotle University School of Medicine, Papageorgiou Hospital, 546 43 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4072-3591","authenticated-orcid":false,"given":"Elizavet","family":"Lazaridou","sequence":"additional","affiliation":[{"name":"Second Department of Dermatology and Venerology, Aristotle University School of Medicine, Papageorgiou Hospital, 546 43 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zoe","family":"Apalla","sequence":"additional","affiliation":[{"name":"Second Department of Dermatology and Venerology, Aristotle University School of Medicine, Papageorgiou Hospital, 546 43 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9616-2001","authenticated-orcid":false,"given":"Aikaterini","family":"Patsatsi","sequence":"additional","affiliation":[{"name":"Second Department of Dermatology and Venerology, Aristotle University School of Medicine, Papageorgiou Hospital, 546 43 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Styliani","family":"Siskou","sequence":"additional","affiliation":[{"name":"Second Department of Dermatology and Venerology, Aristotle University School of Medicine, Papageorgiou Hospital, 546 43 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anastasia","family":"Trigoni","sequence":"additional","affiliation":[{"name":"Second Department of Dermatology and Venerology, Aristotle University School of Medicine, Papageorgiou Hospital, 546 43 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christina","family":"Kemanetzi","sequence":"additional","affiliation":[{"name":"Second Department of Dermatology and Venerology, Aristotle University School of Medicine, Papageorgiou Hospital, 546 43 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5573-1754","authenticated-orcid":false,"given":"Adam","family":"Reich","sequence":"additional","affiliation":[{"name":"Department of Dermatology, Faculty of Medicine, University of Rzesz\u00f3w, 35-959 Rzeszow, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,30]]},"reference":[{"key":"ref_1","first-page":"984","article-title":"Rapidly Enlarging Growth of the Proximal Nail Fold","volume":"29","author":"High","year":"2003","journal-title":"Dermatol. 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