TUMOR REMNANTS WITHIN GIANT-CELLS FOLLOWING IRRADIATION OF CUTANEOUS SQUAMOUS-CELL CARCINOMA

BACKGROUND. The histopathologic effects of curative doses of radiation therapy on cutaneous squamous cell carcinoma (SCC) have not been well described in the dermatologic literature. OBJECTIVE. To understand th e histopathologic process of cutaneous SCC involution following radiat ion treatment. METHODS. Hematoxylin-eosin stain and immunoperoxidase s tains for keratin were performed on tissue from the site of a primary cutaneous SCC 2 months after completion of fractionated radiation ther apy (7000 cGy total) but prior to clinical involution. RESULTS. Histop athological examination of the irradiated SCC revealed dermal keratin pearls and keratinocytic necrosis resembling apoptosis as well as infl ammation and foreign body giant cell reaction. Immunoperoxidase staini ng for keratin revealed cellular remnants of cutaneous SCC without int act keratinocytic nuclei within giant cells. CONCLUSION. Complete clin ical resolution of the SCC over the next several weeks without recurre nce after 15 months confirmed the histopathologic findings of tumor de struction by primary radiation therapy. (C) 1998 by the American Socie ty for Dermatologic Surgery, Inc.