Melanonychia is a brown or black stain in your fingernail or toenail. You can have a dark line on one nail, a few nails, or all of your nails. The line is caused by the natural color in your body ...

Despite a high frequency of atypical features, longitudinal melanonychia (LM) in children is associated with an exceedingly low rate of malignancy. LM — a pigmented band in the nail plate caused by ...

Longitudinal melanonychia is the occurrence of tan, brown, or black pigmented bands along the length of the nail bed. It occurs most often in dark-skinned individuals, and it affects girls more often ...