Noticed a dark streak on your nail? It could be melanonychia a condition where pigmentation appears in the nail plate, often as a brown or black line. While it's commonly 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 Melanonychia: moles and melanoma on the nail Dr. Podlipnik Diagnosis of Melanonychia Dermatologic Clinics