Longitudinal Melonychia: Clinical Evaluation and Biopsy Technique

Melanoma of the Hand: Current Practice and New Frontiers

“…Sir Jonathan Hutchinson in 1886 called it “melantotic whitlow” given its similarities with nail infections (see Figure 1 ) [ 25 ]. The differential, of a pigmented nail lesion does include infection as well as hematoma, chemical exposure, medication reactions, HIV, vitamin deficiencies, as well as many others [ 3 , 26 ].…”

“…Characteristics of the nail bed that make histologic diagnosis challenging include a poorly delineated dermis, minimal subcutaneous fat, propensity for epidermal hyperplasia and lack of an epidermal granular layer. This has led some to abandon the Breslow classification for treatment decisions, instead considering lesions limited to the matrix itself as in situ lesions and those full thickness to be treated as invasive often electing to perform amputation [ 26 ].…”

“…For physicians not familiar with nail bed repair techniques, a punch biopsy, with or without nail plate removal, can be performed. For physicians familiar with nail repair techniques a diamond shaped incisional biopsy or linear excision can be performed [ 26 ].…”

“…With regard to subungual melanoma we have already discussed the challenges with histologic diagnosis. Until further evidence is brought to bear on the subject, SLN biopsy should be offered to all patients with invasive subungual melanoma for staging of regional nodes [ 26 ].…”

Site Selection

“…Although the most widely accepted one is a longitudinal full-thickness excisional procedure, given that shave biopsies fail to evaluate the thickness of the lesion. [14] Before obtaining a biopsy, the nail plate is viewed end-on with dermoscopy, because lesions that are present in the dorsal nail plate reflect a melanocytic origin at the proximal nail matrix, whereas lesions presented in the ventral nail plate correspond to origin at the distal nail matrix [2] Various choices for biopsy are available depending on the presence of Hutchinson´s sign, width and location of the nail band, and the origin within the matrix of the nail band. Regardless of the biopsy type, pain management and control of bleeding are paramount.…”