THE HITHERTO reported cases of atypical blue nevus may be divided histologically into the following three categories:
Those with the combination of ordinary pigmented nevus cells occurring directly beneath the epidermis and fusiform blue nevus cells in the deeper layer of the cutis. In some areas the two types of nevus cells may be intimately mixed with each other. Such cases have been described by Stranz1 (3 cases), Armuzzi2 (3 cases), Kreibich3 (1 case) and Montgomery and Kahler4 (4 cases). Strictly speaking, it is doubtful whether the cases of Dubreuilh and Petges,5 Ribbert,6 Fischer7 and Bezecny,8 sometimes cited by others, actually belong to this category.
Cases with the combination of increased pigmented cells in the epidermis and blue nevus cells in the cutis, where the two types of cells are separated by a definite border zone, at least in
TARO KAWAMURA. ATYPICAL BLUE NEVUSReport of a Case. Arch Derm Syphilol. 1950;62(3):395–399. doi:10.1001/archderm.1950.01530160049006