Adamantinoma of the tibia. An eccrine carcinoma.

Recent debate concerning adamantinoma of long bone has centered around its histogenesis. The two major proposals have advocated endothelial or epithelial origin. Recent electron microscopic studies and immunoperoxidase evaluation using keratin and factor VIII-related antigen have supported an epithelial derivation. We have studied such a tumor and applied enzyme histochemical techniques in addition to previous methods. Electron microscopy disclosed desmosomes and intermediate-sized filaments. Positive carcinoembryonic antigen and keratin and negative factor VIII-related antigen confirm previous studies and support an epithelial origin. We demonstrated a correlation between enzyme staining of the tumor cells when compared with normal eccrine gland controls. Our evidence thus points to the adamantinoma of tibia as showing eccrine differentiation.