PSEUDOEPITHELIOMATOUS HYPERPLASIA IN CHRONIC CUTANEOUS WOUNDS - A FLOW CYTOMETRIC STUDY

Cutaneous squamous cell carcinomas (SCC) arising in a setting of chron ic regeneration and repair tend to be highly aggressive lesions progno stically distinct from SCC arising in solar-damaged skin. Full thickne ss thermal injury and chronic nonhealing ulcers are predisposing condi tions in up to 2% of SCC. A significant association has been suggested to exist between pseudoepitheliomatous hyperplasia (PH) and SCC. Thre e-hundred-eighty-six surgical cases of skin excised secondary to sever e burns (n=254) or chronic ulcers (n=132) were reviewed, yielding 43 ( 11%) with PH. Flow cytometric DNA analysis was performed on paraffin-e mbedded sections. Thirty cases without PH were studied in addition to the 43 cases with PH. The majority (39/43) of the PH cases showed a si ngle diploid population with a mean S-phase of 13.7% Four cases (9.3%) showed an aneuploid peak. All cases without PH were diploid with a me an S-phase of 9.0%. In this study, PH was present in 11% of cases revi ewed, and showed a 50% mean higher S-phase than comparable cases witho ut PH. Aneuploidy was present in 9.3% of the PH cases studied. SCC may arise from a subgroup of PH in a background of rapidly proliferating keratinocytes. (C) Munksgaard 1994.