BACKGROUND: In this paper a broad review of nail biopsy is presented, emphasizing its anatomy, embryology, histology and histopathology. The indication and purpose of nail biopsy as well as the techniques available are reviewed in detail. OBJECTIVE: Define the appropriate site for nail biopsy according to nail disorder, compare two different methods of nail specimen softening: soaking in 20% potassium hydroxide and in 10% aqueous solution of Tween 40 and establish a routine for the nail biopsy procedure. METHODS: Our group studied eleven patients with nail disease who presented at the Dermatology Department in Pedro Ernesto University Hospital for a definite diagnosis. Twelve biopsies were performed. RESULTS: There were no differences in the softness achieved with the two methods and none harmed the cytologic and histologic analysis. CONCLUSIONS: The authors concluded that nail biopsy is a safe and useful procedure for nail diseases when clinical and laboratory methods fail to reach a diagnosis. A complete and thorough understanding of the nail unit anatomy is necessary to perform the procedure
biopsy; nail diseases; pathology
