Tibial adamantinoma

Abstract

Adamantinoma is a malignant tumor rarely affecting the long bones. Three cases of adamantinoma of the tibia are reported. All of these cases were treated by local excision but the tumor recurred. In case 3, there were inguinal and pulmonary metastases. She died from metastases one year after amputation of the affected limb. The findings of the tumor under light microscope were in agreement with the theory that the tumor was of epithelial origin. The electron microscopic study of the neoplasm in this case revealed that the cytoplasm of tumor cells was very scanty. There was a large amount of bundles of tonofilaments and free ribosomes, but other cell organelles were seldom seen. At portions of tumor cell mass, discontinuous basal membrane adjacent to the interstitial tissue were demonstrated. Microvilli were found to extend into intercellular spaces. There were also intercellular desmosomes. Based on these findings, it seems that this tumor probably originated from squamous cells. Because this tumor does not have typical clinical and roentgenographic characteristics, biopsy is always necessary for its diagnosis. Local excision of the tumor is usually followed by recurrence; therefore, amputation of the involved extremity is proposed.