Pigmented epithelioid melanocytoma (PEM; also known as atypical epithelioid blue nevus [EBN] and animal-type melanoma) is a rare, heavily pigmented melanocytic neoplasm with borderline malignant potential (categorized by the World Health Organization [WHO] as a "high-grade intermediate melanocytic tumor"). It frequently involves regional lymph nodes. Distant metastases are very rare, and deaths from PEM are not typical but have been reported.

PEM is seen in men and women of every race / ethnicity and age, but it is most commonly found in children, teenagers, and young adults (the median age is 20-27 years). It can occur in any part of the body, including the genital area and on the conjunctiva, but most of the lesions have been described on the extremities, followed by the head and neck.

PEM may arise in association with another melanocytic nevus, such as a compound nevus. This type is known as the combined type of PEM, or epithelioid blue nevus. Combined PEMs are a manifestation of Carney complex.