Histochemical study of the biphasic cellular pattern of tubular adenoid cystic carcinoma with azophloxine, amidoblack and acid blue.

A tubular adenoid cystic carcinoma of the soft palate was studied histochemically using tannic acid-phosphomolybdic acid-Azophloxine (TPAzf), tannic acid-phosphomolybdic acid-Amidoblack (TPA) and tannic acid-phosphomolybdic acid-Acid Blue techniques. At the periphery of some tumor nests a few spindle cells were noted stained intensely red, blue-green and dark blue with TPAzf, TPA and TPAcB respectively. The apical portion or the whole cytoplasm of the cuboidal, eosinophilic cells that lined the central lumina of most neoplastic nests showed a similar tinctorial behavior. On the basis of their location and staining properties, the spindle cells were recognized as myoepithelial. On the other hand, the tinctorial behavior of eosinophilic cells was attributed to the dye binding by a conspicuous terminal bar-terminal web system or by tonofibrils accumulated in their cytoplasm as a result of squamous metaplasia. An inverse relation between the presence of myoepithelial cells at the periphery of tumor nests and the increasing thickness of terminal bar-terminal web system or the appearance of numerous tonofibrils in the eosinophilic cells was also noted.