title: Ossifying pleomorphic adenoma of the maxillary antrum.
abstract: An unusual case of pleomorphic adenoma with exuberant bone formation, occurring in the maxillary antrum of a 21-year-old male and showing repeated recurrence, is reported. In contrast to the endochondral ossification in the previous reported cases of pleomorphic adenoma, direct deposition of osteoid by metaplastic myoepithelial cells is suggested to explain the bone formation. The difficulties of distinguishing this tumour from osteosarcoma during intraoperative diagnosis are discussed.
authors.affiliation: Institute of Pathology, Queen Elizabeth Hospital, Hong Kong.
authors.forename: K C
authors.initials: KC
authors.lastname: Lee
authors.forename: J K
authors.initials: JK
authors.lastname: Chan
authors.forename: Y W
authors.initials: YW
authors.lastname: Chong
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008443:Maxillary Sinus; D008444:Maxillary Sinus Neoplasms / Q000473:pathology*; D009373:Neoplasms, Germ Cell and Embryonal / Q000473:pathology*; D009999:Ossification, Heterotopic / Q000473:pathology*; D012516:Osteosarcoma / Q000175:diagnosis