Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, New York 10016, USA.
Dermatol Ther. 2012 Nov-Dec;25(6):491-7. doi: 10.1111/j.1529-8019.2012.01554.x.
Longitudinal melanonychia (LM) is a common presenting problem in general dermatology, and represents a diagnostic challenge to clinicians given its broad differential diagnosis that includes both benign and malignant entities. The decision of when a biopsy is required is incredibly challenging for dermatologists. Dermoscopy is a noninvasive technique that enhances the clinical evaluation of LM, and has demonstrated potential in improving the clinical decision making as to whether or not to biopsy LM. However, it is critical for clinicians to understand the limitations of dermoscopy, and that although it is able to add new criteria for the diagnosis of ungual pigmentation, it does not replace histopathologic diagnosis. Biopsy of the nail unit should be performed in any case where doubt based on the clinical evaluation exists.
纵向黑甲（LM）是皮肤科常见的就诊问题，由于其广泛的鉴别诊断包括良性和恶性病变，给临床医生带来了诊断上的挑战。何时进行活检的决策对皮肤科医生来说极具挑战性。皮肤镜检查是一种非侵入性技术，可增强对 LM 的临床评估，并已证明在改善是否对 LM 进行活检的临床决策方面具有潜力。然而，临床医生必须了解皮肤镜检查的局限性，并且尽管它能够为甲色素沉着的诊断增加新的标准，但它不能替代组织病理学诊断。只要基于临床评估存在疑问，就应在任何情况下对指甲单位进行活检。
