Nail Matrix Nevus Springer Nature Link Melanonychia is brown or black discolouration of a nail. It may be diffuse or take the form of a longitudinal band. Melanonychia can present in individuals of all ages, including children, and Pigmented Nail Disorders Basicmedical Key Brown black pigmented nail bands (melanonychia) can be a sign of subungual melanoma. This case report describes a child with melanonychia mimicking melanoma caused by green slime. Presumably, the slime embedded in the This dark line or discoloration on the nail can be a common condition called melanonychia, basically, extra pigment in the nail plate. In many people, especially those with more melanin in their