Minagawa Akane
Department of Dermatology, Shinshu University School of Medicine, Matsumoto, Japan.
J Dermatol. 2017 May;44(5):518-524. doi: 10.1111/1346-8138.13657.
Making a definitive diagnosis of seborrheic keratosis (SK) can be challenging for the naked eye due to its wide variation in clinical features. Fortunately, however, most cases of SK exhibit the typical dermoscopic findings of fissures and ridges, hairpin vessels with white halo, comedo-like openings, and milia-like cysts, all of which are helpful to distinguish SK from melanoma, melanocytic nevus, squamous cell carcinoma, basal cell carcinoma (BCC) and other skin tumors. Histopathologically, these dermoscopic characteristics correspond to papillomatous surface of the epidermis, enlarged capillaries of the dermal papillae, pseudohorn cysts in the epidermis opened to the surface of the lesion and intraepidermal cysts, respectively. Clinicians should bear in mind that the clonal type of SK dermoscopically mimics melanoma and BCC by the presence of globule-like structures, while regressing SK exhibits a granular pattern that is similar to the peppering found in melanoma. Furthermore, milia-like cysts alone are insufficient for a conclusive diagnosis of SK because melanoma in rare cases displays cysts along with other SK-like dermoscopic findings.
由于脂溢性角化病（SK）的临床特征差异很大，仅凭肉眼做出明确诊断具有挑战性。然而，幸运的是，大多数SK病例表现出典型的皮肤镜表现，如裂隙和嵴、有白色晕的发夹样血管、粉刺样开口和粟丘疹样囊肿，所有这些都有助于将SK与黑色素瘤、黑素细胞痣、鳞状细胞癌、基底细胞癌（BCC）和其他皮肤肿瘤区分开来。在组织病理学上，这些皮肤镜特征分别对应于表皮的乳头瘤样表面、真皮乳头的毛细血管扩张、向病变表面开放的表皮假角囊肿和表皮内囊肿。临床医生应牢记，SK的克隆型在皮肤镜下通过存在球状结构模仿黑色素瘤和BCC，而消退期SK表现出一种颗粒状模式，类似于黑色素瘤中的点状表现。此外，仅凭粟丘疹样囊肿不足以确诊SK，因为在罕见情况下，黑色素瘤会与其他SK样皮肤镜表现一起出现囊肿。
