A COMPARISON OF FROZEN AND PARAFFIN SECTIONS IN DERMATOFIBROSARCOMA PROTUBERANS

BACKGROUND. Dermatofibrosarcoma protuberans (DFSP) is a tumor with a h igh local reoccurrence rate. Mohs micrographic surgery offers the high est cure rate. However, differentiating minimal residual tumor from no rmal skin can be difficult during Mohs surgery. OBJECTIVE. To clarify the problem of determining when a tumor-free plane had been achieved d uring Mohs surgery for a DFSP. METHODS. In two patients With DFSPs, we compared frozen and paraffin-embedded sections extending from tumor t o normal skin, using both H & E and CD34 stains. RESULTS. On frozen, b ut not paraffin-embedded, sections scattered dermal spindle cells were seen in normal skin. CONCLUSIONS. Scattered dermal spindle cells in t he dermis of normal skin make it difficult to differentiate minimal re sidual tumor from normal dermis during Mohs surgery. A biopsy of norma l skin can be useful as a control in this setting. (C) 1998 by the Ame rican Society for Dermatologic Surgery, Inc.