Dermoscopic and reflectance confocal microscopic features of sebaceoma, sebaceous adenoma and sebaceous carcinoma: a systematic review

Sebaceous tumors (STs) comprise a heterogeneous group of cutaneous and mucosal neoplasms characterized by sebaceous differentiation. Although sebaceous hyperplasia and the yellowish hue as characteristic of STs have been well-documented in literature, detailed dermoscopic and reflectance confocal microscopic features of sebaceoma, sebaceous adenoma, and sebaceous carcinoma have not been comprehensively investigated to date. We conducted a systematic literature review of PubMed, Scopus, Web of Science, and CENTRAL databases from inception through April 2025, following PRISMA guidelines. The protocol was prospectively registered in PROSPERO (CRD420251040944). In total, seventy-one histologically confirmed STs in 55 patients (40% female, median age 66) were analyzed, including 11 sebaceomas (16%), 23 sebaceous adenomas (32%), and 37 sebaceous carcinomas (52%). On dermoscopy, a pink homogeneous background with monomorphic elongated-crown or arborizing vessels was observed in 80–96% of benign STs. Sebaceous carcinoma exhibited distinct features, such as larger size (mean 16 × 12 mm), ulceration, and polymorphic vascular patterns, particularly linear irregular and arborizing vessels, suggesting neoangiogenesis and greater biological aggressiveness. Reflectance confocal microscopy revealed sebocytes’ morphology, defined by cuboidal cells with dark nuclei and hyper-refractive cytoplasm. Nevertheless, its diagnostic accuracy is limited by low cell density, inflammation, and keratin buildup. Overall, yellow coloration, while suggestive of sebaceous differentiation, shows limited diagnostic specificity. Integrating clinical and dermoscopic findings can improve the detection of STs, particularly sebaceous carcinoma. Standardized criteria and further validation across diverse skin types are warranted.