ABSTRACT
@#Deletions and amplifications of genes often occur during multistep progression from oral precancer, seen as oral epithelial dysplasia (OED) to cancerous stage. These genetic alterations could be used as markers to aid in detection of oral squamous cell carcinomas (OSCC). This study explored the use of multiplex ligation-dependent probe amplification (MLPA) technique in detecting OSCC and OED specific genetic alterations. MLPA was used to detect gains and losses of 106 genes in DNA extracted from frozen tissue samples of 10 OSCC and 10 noncancer patients. Two biopsies of OED were analyzed to explore the alterations in oral potentially malignant disorders. There were significant differences (p<0.001) in the number of alterations in OSCC and dysplasia compared to non-cancer samples respectively. The most frequently altered genes in OSCC were PTP4A3, RECQL4, ATM, and KLK3 (60%). Five genes (MYC, SLA, TNFRSF1A, MESDC1, MIF) were altered in 50% of OSCC samples. These nine genes were specific to OSCC samples (p<0.05). Some genes, including MYB, MET, CASP2, SLA and PTEN occurred in 50% of OED samples. MLPA was able to detect genetic alterations, that are present only in the OSCC samples and showed potential to be used as an adjunctive tool in early diagnosis of OSCC.
ABSTRACT
This was a retrospective study of dentigerous cysts in people from the Singapore-Malaysian region. The purpose of this study was to present the clinicopathologic features of dentigerous cysts in the Oriental population and to compare these data with those from other reported studies. Biopsy records from 1981 to 1993 of 119 cases of dentigerous cysts from patients in Malaysia and Singapore showed that 36.1% of patients were female and 63.9% patients were male. Among patients with cysts, 70.5% were Chinese, 23.2% were Malays, 2.7% were Indian and 3.6% were other ethnic groups. The mean age of these patients was 30.2 +/- 17.3 years with a peak incidence occurring in the second and third decades. The location of the lesions was almost equal to the maxilla (50.9%) and the mandible (49.1%). There was a marked predilection for the posterior mandible (42.7%) followed by the anterior maxilla (38.2%). Histologically, 90.8% of the cysts were lined by a non-keratinised stratified squamous epithelium. The cyst linings were mainly thin (90.0%) with 38.7% of cases having a mixed thick and thin lining. Mucous metaplasia was observed in 9 (7.6%) cases. Rushton bodies were seen in 3.4% of cases. Cholesterol clefts in the epithelial lining and lumen were found in 16.8% cases while 12.6% of cases exhibited cholesterol clefts in the cyst wall. Other cellular structures within the cyst wall were lymphocytes (66.4%), plasma cells (52.1%), Russell bodies (16.0%) and histiocytes (4.2%). Odontogenic keratocysts were observed in 5.0% of cases. One case of adenomatoid odontogenic tumour was also observed. Epithelial atypia was seen in 9.2% of cases, islands of stratified squamous epithelial cells in 8.4% of cases while one case showed a combination of these two features. In conclusion, some clinical features seen in this study are similar to that for the Caucasian population such as prevalence in male, peak incidence in the second and third decades and the predilection for the posterior mandible and anterior maxilla. Histopathologically, odontogenic keratocyst and adenomatoid odontogenic tumour were observed in dentigerous cysts.
