摘要甲病种类繁多，近年其诊断与治疗取得一些进展，但仍面临诸多挑战，如纵行黑甲、罕见的甲单元特异性肿瘤、甲营养不良等。纵行黑甲存在黑素瘤可能，而活检与手术本身是肢端黑素瘤的诱发因素，因此是否手术以及如何把握手术原则很重要。此外，在诊疗过程中应结合年龄、临床评估、皮肤镜表现以及病理检查进行评估，最终做到恶性黑甲不漏诊，良性黑甲不畸形。临床上对特发于甲单元的少见肿瘤临床表现和病理学特征的总结较少，诊断难度高，尤其甲母质细胞癌和甲鞘癌属恶性肿瘤，损害大，本文重点描述从而提醒临床医生避免漏诊。甲营养不良病因复杂，由炎症性疾病导致的甲营养不良可选用局部或系统药物治疗，而由遗传、足趾畸形、行走姿势不当、机械性损伤、甲沟慢性炎症导致的各种甲畸形则需进行物理或手术矫正。本文将对这几种甲病诊疗中存在的挑战和相应对策进行探讨。

abstractsIn recent years, some progress has been made in the diagnosis and treatment of nail diseases, but there are still many challenges, such as longitudinal melanonychia, rare nail unit-specific tumors and nail dystrophy. Longitudinal melanonychia may develop into melanoma. Besides, biopsy and surgery are triggering factors for acral melanoma, so it is important to decide whether to operate and how to apply operating principles in clinic. In addition, the diagnosis and treatment should be based on patients′ age, clinical evaluation results, dermoscopic findings and pathological examinations, so as to avoid missed diagnosis of malignant melanonychia and deformities from treatment of benign melanonychia as far as possible. There are few summaries of clinical manifestations and pathological features of rare nail unit-specific tumors, and their diagnosis is difficult. In particular, onychocytic carcinoma and onycholemmal carcinoma are malignant tumors with great harm, so this article focuses on the two kinds of tumors to remind clinicians to avoid missed diagnoses. The etiology of nail dystrophy is complex. Nail dystrophy caused by inflammatory diseases can be treated with topical or systemic drugs, while various nail deformities caused by genetic factors, toe deformities, improper walking posture, mechanical injuries, and chronic inflammation of the nail groove are in need of physical or surgical correction. This article gives insight into challenges and strategies for the diagnosis and treatment of the above nail diseases.