Hamartomatous proliferations of odontogenic epithelium within the jaws: a potential histogenetic source of intraosseous epithelial odontogenic tumors.
BACKGROUND
The jawbone is replete with a vestige of odontogenesis. The overall consensus is that intraosseous remnants of the enamel organ and dental lamina are the only histogenetic option for central epithelial odontogenic tumors. Curiously, incipient tumors or possible precursor conditions of residual odontogenic epithelium have rarely been reported in the literature.


METHODS
We microscopically evaluated 39,660 biopsy samples to determine the presence of a tumor-like odontogenic epithelial nodule in the maxilla and mandible.


RESULTS
Seven intraosseous specimens that associated with a focal proliferation of odontogenic epithelium were retrieved. Six hamartomatous processes showed four different morphologic patterns comparable with the tumor nests comprising ameloblastoma (n = 1), squamous odontogenic tumor (n=1), calcifying epithelial odontogenic tumor (n=2) and calcifying cystic odontogenic tumor (n=2). Among six lesions, four were the intrafollicular development. The remaining case of interest was multiple hyperplastic clear rests of Malassez in association with an impacted tooth.


CONCLUSIONS
Although it is impossible to predict the fate of these microscopic structures of hamartomatous character, the present case series indicates that any of the dormant embryonic residues of odontogenic epithelium can return to an active state, capable of non-reactive, probably neoplastic proliferation of pathological significance.
Ide
F
F
Division of Pathology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan. idef@dent.meikai.ac.jp
Obara
K
K
Yamada
H
H
Mishima
K
K
Saito
I
I
Horie
N
N
Shimoyama
T
T
Kusama
K
K
D000293:Adolescent; D000564:Ameloblastoma / Q000209:etiology; D002648:Child; D004848:Epithelium / Q000196:embryology; D006222:Hamartoma / Q000150:complications*; D006801:Humans; D007571:Jaw Diseases / Q000150:complications; D007573:Jaw Neoplasms / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D018307:Neoplasms, Squamous Cell / Q000209:etiology; D009808:Odontogenic Tumors / Q000209:etiology*; D014083:Tooth Germ / Q000166:cytology