Cellular blue nevi with myxoid change--diagnostic difficulties and the review of the literature.

We report three cases of a rare morphologic variant of the cellular blue nevus, which usually occurs in young patients on the buttocks and lumbar area. This variant is characterized by the myxoid degeneration of the stroma, which separates alveolar nests of nevus cells. The uncommon occurrence and atypical pathologic features may bring about diagnostic pitfalls and unnecessary excessive treatment modalities, therefore, we tried to re-evaluate the criteria of diagnosis of cellular and malignant blue nevi.