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  • This chapter covers the most common benign and malignant neoplasms of the nail unit.

  • It expands and discusses the update on diagnostic and therapeutic advances.


  • It is important to know the detailed nail structure prior to understanding tumors of the nail.

  • Due to the potential clinical overlap between benign and malignant lesions, it is important to biopsy any lesion that is persistent, suspicious, or recalcitrant to treatment.


  • As the nail unit has a limited number of responses to injury, it is often difficult to differentiate between inflammatory, infectious, and neoplastic processes.

  • A comprehensive physical examination is critical in localizing the origin of nail unit pathology.


  • The human nail unit is a set of complex structures that is important for both form and function.

  • It is important to see a dermatologist for any persistent and suspicious nail changes.


The nail unit is a complex anatomic structure that is important for both form and function. Tumors of the nail unit encompass many of the same benign and malignant entities that occur in the nail or periungual apparatus tissue. More than 130 different tumors and tumor-like lesions under and around the nail unit have been described. Most of them are rare and have a variety of clinical presentations.1

Diagnosis and treatment are often delayed due to altered morphology of nail tumors and reluctance to biopsy the nail unit because of the risk of permanent nail dystrophy. Recognition of how nail tumors commonly present and the indications for biopsy is essential for management of the disease.

This chapter covers the most important nail tumors and discusses the approaches to the diagnosis and treatment of benign and malignant tumors of the nail unit.



Epidemiology & Clinical Presentation

Verruca vulgaris (wart) is the most common nail unit tumor and affects fingernails more frequently than toenails.2 Periungual verrucae are considered a common wart, and as such, adolescents are more commonly affected, with the highest incidence occurring between the ages of 12 and 16 years. Although they are more common in children, verrucae also frequently develop in patients who bite or pick their nails, suck their fingers, are exposed to occupational hazards (prolonged contact with water and handling of poultry, meat, and fish), or are immunocompromised.2

Verrucae occur on the proximal nail fold, lateral nail fold, or the hyponychium where a granular layer exists. Most commonly, they appear as other common warts with a classic description as a skin-colored papule with a rough surface that produces pinpoint hemorrhages when the lesion is pared (Figure 18-1). Other classic features include pain with compressive pressure of the verruca ...

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