Recurrence of keratocystic odontogenic tumor: clinicopathological features and immunohistochemical study of the Hedgehog signaling pathway.
OBJECTIVE
Critical factors responsible for the recurrence of keratocystic odontogenic tumor (KCOT) were examined.


METHODS
The clinicopathological features were retrospectively studied in 74 patients with 75 sporadic KCOTs. From the 75 KCOTs, 23 were examined for the expression of Sonic Hedgehog (SHH), Patched and Smoothened (SMO) by immunohistochemistry.


RESULTS
Recurrence in multilocular lesions was more frequent than in unilocular lesions. Nine (64%) of 14 multilocular lesions recurred, in contrast to 2 (7%) of 27 unilocular lesions (p = 0.0350). The average length of recurrent lesions (62.8 +/- 6.5 mm) was larger than that of nonrecurrent lesions (43.0 +/- 4.0 mm; p = 0.0363). The immunoreactivity of proliferation-related SMO in KCOTs with recurrence was higher than that of those without recurrence (p = 0.0475), whereas the expressions of a ligand, SHH, and an inhibitory receptor, Patched, were not associated with KCOT recurrence. The expressions of SHH and SMO showed inverse correlation in whole KCOT (p = 0.0318).


CONCLUSIONS
These findings suggest that recurrence of KCOT is associated with multilocular large lesions and high SMO expression.
Department of Oral and Maxillofacial Surgery, Nara Medical University School of Medicine, Kashihara, Japan.
Takahiro
T
Yagyuu
Tadaaki
T
Kirita
Tomonori
T
Sasahira
Yukiko
Y
Moriwaka
Kazuhiko
K
Yamamoto
Hiroki
H
Kuniyasu
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D053823:Hedgehog Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008339:Mandibular Neoplasms / Q000378:metabolism* / Q000473:pathology*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009808:Odontogenic Tumors / Q000378:metabolism* / Q000473:pathology*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D012189:Retrospective Studies; D000072086:Smoothened Receptor
D053823:Hedgehog Proteins; D043562:Receptors, G-Protein-Coupled; C491023:SMO protein, human; D000072086:Smoothened Receptor