ABSTRACT
A number of problems affect the nail and the tissues around it. The type of biopsy recommended will depend on the primary tissue involved. In the diagram opposite the numbers illustrate the punch biopsy taken at the base of a narrow pigmented band. Painful hard areas of keratin can form, particularly under the great toenail, in which case it may be due to tight-fitting footwear. However, there are other causes, and it may be necessary to take a punch biopsy with or without the need to clip back the nail a little. It is essential to visualize the nail bed if there is a disease process beneath the nail plate. A small lesion can sometimes be dealt with by opening a small window in the nail plate using a punch biopsy. There is always concern that Pigmented longitudinal streak might represent a malignant lesion developing in the matrix. A punch biopsy from the base of the streak is taken.
