Experimentally-induced jaw sarcoma in the rat.

Jaw bones differ embryologically from limb bones and the axial skeleton as they are derived from migrating neural crest cells and are not preformed in cartilage as are the latter bone types. The purpose of the present study was to determine whether this embryologically different nature implied a different response to a locally applied carcinogenic compound, 4-hydroxyamino-quinoline-1-oxide; this within the context of elucidating why human jaw osteo- and fibrosarcomas behave differently from identical tumours elsewhere in the skeleton. Rat mandibles were exposed to the carcinogen. Of the 5 rats used, 3 developed tumours which were however histologically identical to the tumours experimentally induced in the limb bones by the same carcinogenic agent. As a consequence, it is concluded that the embryologically different nature of the jaw bone does not imply that local exposure to a carcinogenic agent induces other kinds of tumours as are seen in the extragnathic skeleton.