Melanocytes of a melanocytic nevus in a lymph node from a patient with a primary cutaneous melanoma associated with a small congenital nevus.

Aggregates of melanocytes within the parenchyma of a supraomohyoid lymph node were found in a lymph node dissection from a 52-year-old woman who had a primary cutaneous melanoma that had arisen in association with a small congenital nevus. The melanocytes in the lymph node were interpreted to be those of a benign melanocytic nevus, and not those of malignant melanoma, based on similarities in morphologic features and immunohistochemical staining between the melanocytes in the node and those in the cutaneous congenital nevus.