Pseudolymphomatous folliculitis with marked lymphocytic folliculo- and focal epidermotropism--expanding the morphologic spectrum.

摘要

The term pseudolymphomatous folliculitis (PLF), first coined by Kibbi et al denotes a cutaneous lymphoid infiltrate mostly occurring in the facial region with characteristic hyperplastic and distorted hair follicles and, to a lesser extent, hyperplasia of sweat glands with a peculiar "blastoid" transformation of the luminal epithelium. In 1999, Arai et al published a series of 15 cases on this topic followed by additional 7 cases in 2005. The largest study to date on PLF is by Kazakov et al comprising 42 cases which were characterized in great detail including comprehensive both immunohistochemical and molecular genetic studies. In this study, 17 of the 42 cases showed lymphocytic folliculo-tropism which was "always discrete and focal" and none of the cases showed involvement of the epidermis.