IT IS THE purpose of this presentation to point out a sequence of events which appears to be typical in the development of naevus syringadenomatosus papilliferus, and by doing so to aid in the clinical recognition of this often unsuspected tumor. In addition, a clarification of some debated points in the histogenesis of naevus syringadenomatosus papilliferus will be attempted. The discussion will be restricted to those papilliferous growths which most commonly occur on or near the scalp and which develop in a preexisting lesion. Related tumors, particularly the papilliferous cystadenomas of the vulva, which Anderson1 discussed before this Association three years ago, will not be considered.
Naevus syringadenomatosus papilliferus is judged a rare lesion by most authors. Biberstein (1926),2 Reuterwall (1933),3 and Sachs and Lewis (1937)4 surveyed the older literature and collected approximately 40 cases. Probably an equal number has been added since that