Keloidal basal cell carcinoma after radiation therapy

Abstract

We report a case of keloidal basal cell carcinoma (BCC) that developed after radiation therapy. A 67-year-old Japanese man had received radiation therapy of an unknown amount for three years for the treatment of right cervical lymph node tuberculosis at the age of 7. Within the area of chronic radiation dermatitis, on the right preauricular region, he presented with a skin- colored to erythematous, firm nodule. Histopathologically, this nodule showed features of keloidal BCC. The stroma characteristically demonstrated the prominent, keloidal, thickened collagen bundles standing out against the surrounding actinic-damaged dermis, and well-circumscribed, keloidal collagen bundles that proliferated in a nodular form almost corresponding to a clinically firm, nodular lesion. There was no radiation fibrosis around the keloidal BCC. We discuss the differences between keloidal BCC and morpheiform BCC, and consider keloidal BCC to be a rare variant of BCC from a clinicopathological basis.