Blue nevus: It is blue in color as its melanocytes are very deep in the skin.

For instance, a small blue or bluish black spot, often called a blue nevus, is usually benign but often mistaken for melanoma.

A malignant blue nevus is a cutaneous condition characterized by a sheet-like growth pattern, mitoses, necrosis, and cellular atypia.

Blue nevus (also known as "Blue neuronevus," "Dermal melanocytoma," and "Nevus bleu") is a type of melanocytic nevus.

An Amelanotic blue nevus (also known as a "Hypomelanotic blue nevus") is a cutaneous condition characterized by mild atypia and pleomorphism.

Blue nevus of Jadassohn-Tièche (also known as a "Common blue nevus," and "Nevus ceruleus") is a cutaneous condition characterized by a steel-blue papule or nodule.

A Patch blue nevus (also known as an "Acquired dermal melanocytosis," and "Dermal melanocyte hamartoma") is a cutaneous condition characterized by a diffusely gray-blue area that may have superimposed darker macules.

It is a multiple neoplasia syndrome that is generally characterized by myxomatous neoplasms (cardiac, endocrine, cutaneous and neural), and a host of pigmented lesions of the skin and mucosae, including the rarely occurring epitheloid blue nevus.