Wolkow, Natalie; Freitag, Suzanne K.Read More
Balloon cell nevi are rare variants of nevocellular nevi in which greater than 50% of nevus cells are large and foamy. They are most common in patients under age 30, affecting males and females equally when found in skin. The balloon changes are attributed to defects in melanogenesis that lead to malformed premelanosomes and degenerative changes. Clinically they are indistinguishable from more common nevi. Care needs to be taken in assessing for nuclear atypia in melanocytic lesions with balloon cells as some melanomas may display balloon cell changes.