A microscopical study of 15 intraosseous ameloblastomas revealed the presence of globular hyaline masses in only one of them (6.6%). These masses were confined to the stroma of plexiform areas and especially in regions undergoing cystic degeneration. They were periodic acid-Schiff positive and showed an affinity for acid dyes such as phloxine, acid fuchsin, orange G and picric acid. Regarding their pathogenesis, they are probably formed from extravasation of plasma glycoproteins, condensing and taking up a spheroidal shape in the liquid micro-environment of stromal degeneration under the influence of capillary phenomena.