Conventional Blue Nevi
Soheil Sam Dadras, MD, PhD
Key Facts
Terminology
Benign melanocytic tumor composed of spindle-shaped and dendritic melanocytes and melanophages
Clinical Issues
Occurs in any age, in wide range of locations
Well-demarcated, slightly raised papule (< 1 cm in diameter)
Color ranges from blue to gray to blue-black to black
Excellent prognosis; no significant malignant potential
Microscopic Pathology
Well-demarcated, wedge-shaped dermal melanocytic tumor with variable amount of collagenosis
2 cell types: Slender melanocytes and round melanophages
Heavy to sometimes light mixture of melanophages
 Scanning magnification of a BN shows a symmetrical, wedge-shaped, and evenly pigmented melanocytic tumor present throughout the dermis. |
 High-power magnification of a conventional BN shows 2 cell types: Spindled to dendritic melanocytes  and melanophages  . |
TERMINOLOGY
Abbreviations
Blue nevus (BN)
Synonyms
Dendritic blue nevus, common blue nevus, Jadassohn-Tièche-type nevus
Definitions
Heterogeneous group of acquired and congenital melanocytic tumors
Composed predominantly of spindled to dendritic-shaped melanocytes
Varying degrees of cellularity, intra- and extracellular melanin content, and dermal sclerosis
ETIOLOGY/PATHOGENESIS
Developmental Anomaly
May represent aberrant melanocytic precursor migration in development
CLINICAL ISSUES
Epidemiology
Incidence
