Stromal atypia in anal papillae.

This report describes the occurrence of stromal atypia in anal papillae. The atypia occurred in two of 15 papillae studied and was present in the larger ones. The stromal atypia is similar to that described to occur in vaginal polyps and in entities such as pseudosarcomatous fasciitis, atypical fibroxanthomas of the skin, radiation dermatitis, and giant-cell cystitis. The atypia is considered to be reactive or reparative.