Cellular Blue Nevus

**Semantic type:** Neoplastic Process

**Definition:** A blue nevus characterized by a multinodular cellular infiltrate with a dumb-bell architecture occupying the reticular dermis. The cellular infiltrate often extends into the subcutaneous tissue. The cellular infiltrate is composed of spindle-shaped melanocytes with pale cytoplasm alternating with bundles of pigmented spindle-shaped melanocytes. In occasional cases an increased mitotic activity, focal necrosis, and nuclear pleomorphism may be seen. Such cases with atypical features may have an uncertain malignant potential.

**Synonyms:** - CBN - Cellular Blue Nevus of Skin - Cellular Blue Nevus of the Skin - Cellular blue nevus