Correlation between ploidy status using flow cytometry and nucleolar organizer regions in benign and malignant epithelial odontogenic tumors.
OBJECTIVE
Differentiation between the aggressive benign odontogenic tumors and their malignant counterparts is controversial and difficult. While flow cytometry (FCM) allowed DNA analysis in neoplasia, argyrophilic organizer regions (AgNORs) number and/or size in a nucleus are correlated with the ribosomal gene activity and therefore with cellular proliferation. The aim of this research was to study the diagnostic accuracy of FCM and AgNORs staining in differentiating between benign and malignant epithelial odontogenic tumors and to correlate between these two interventions.


DESIGN
Sixteen benign cases [8 cases of ameloblastoma (AB) and 8 cases of keratocystic odontogenic tumor (KCOT)] and 13 malignant epithelial odontogenic tumors [8 cases of ameloblastic carcinoma (ABC) and 5 cases of clear cell odontogenic carcinoma(CCOC)] were included in the current study. For FCM analysis, a single cell suspension from Formalin fixed paraffin-embedded (FFPE) tumors was prepared according to a modified method described by Hedley (1989) and AgNORs staining were performed in accordance to the Ploton protocol (1986). Analysis of AgNORs was performed using both quantitative and qualitative methods.


RESULTS
The work revealed that all the examined tumors were diploid, except for 40% of CCOC cases. The S-phase fraction (SPF) value, AgNORs count and AgNORs area/cell showed statistically significant difference on comparing benign and malignant groups. A weak positive correlation was observed between SPF and AgNORs count.


CONCLUSION
The SPF value was considered to be more sensitive and specific in differentiation between aggressive benign and malignant epithelial odontogenic tumors in comparison to AgNORs counting.
['Mohamed Mahmoud|Sarah Ahmed|SA|', 'El-Rouby|Dalia Hussein|DH|', 'El-Ghani|Safa Fathy Abd|SF|', 'Badawy|Omnia Mohamed|OM|']
D018262:Adenocarcinoma, Clear Cell D000564:Ameloblastoma D005434:Flow Cytometry D006801:Humans D009697:Nucleolus Organizer Region D009808:Odontogenic Tumors D011003:Ploidies D012680:Sensitivity and Specificity D013194:Staining and Labeling
Flow cytometry AgNORs Ameloblastoma Keratocystic odontogenic tumor Ameloblastic carcinoma Clear cell odontogenic carcinoma