Balloon cell nevi

Abstract

Eighteen examples of balloon cell nevi are reviewed. These small pigmented melanocytic lesions occurring largely during the first three decades of life are clinically indistinguishable from other nevi. Histologically they are identified by the presence and preponderance of large cells with characteristic foamy cytoplasm (Blasenzellen). The authors propose that the balloon cells are unusual altered nevus cells, based upon morphologic and histochemical similarities and transitional or intermediate forms. They hypothesize further that the unusual appearance of the balloon cell is due to an arrest in the biosynthesis of the melanin granule, resulting in the accumulation of protyrosinase vesicles. Balloon cells are also found in blue nevi, malignant melanomas and melanocytic tumors of the eye.