MATERIALS AND METHODS: This was a descriptive, retrospective study of odontogenic tumours diagnosed from January 2007 to December 2014 at this centre. The odontogenic tumours were classified using the 2005 World Health Organization classification system.
RESULTS: Among 2,733 biopsy specimens, 173 cases were diagnosed as odontogenic tumours (6.3%), of which 171 (98.8%) are benign and 2 (1.2%) are malignant. The most frequently encountered tumour was ameloblastoma (n=96, 55.5%), followed by keratocystic odontogenic tumour (KCOT) (n=38, 22.0%) and odontomas (n=16, 9.2%). Malignant tumours accounted for 1.2% of the tumours. Most ameloblastomas and KCOTs affected the mandible preferentially. The mean age was 33.5 (± 17.8) years and 64.7% of patients were in the age group of 10 to 39. Odontogenic tumours were slightly more common in males, with a male to female ratio of 1.4:1.
CONCLUSION: The findings of this study are similar to the other studies in Asia in which the most common tumour encountered is the ameloblastoma, followed by KCOT. The most common signs and symptoms are pain and swelling, while paraesthesia and root resorption are less frequently reported. Such clinical and radiographic features should alert the clinician of a possible odontogenic tumour and though rare, malignant tumours should also be included in the differential diagnoses.
OBJECTIVE: The study aims to determine the concordance between HER2 protein IHC score and its gene status by dual-colour dual-hapten in-situ-hybridization (DDISH) study.
MATERIALS AND METHODS: Retrospective study was performed on 767 referred breast cancer cases over a period of five years. The HER2 IHC score (the initial and repeat test score) and the results of HER2 gene status by DDISH were retrieved from the histopathological reports. The agreement between initial IHC score with repeat test score was measured using Cohen Kappa. Chi square test analyzed the association between HER2 IHC score with its gene status by DDISH.
RESULTS: The concordance of HER2 IHC score between the initial and repeat test were 52.7% and 89.4% for IHC score 2+ and 3+ respectively. There was moderate agreement of HER2 IHC score between the initial and repeat test score (ϰ = 0.526, p<0.001). A significant association noted between HER2 IHC score with its gene status by DDISH (p<0.001). Only 56 out of 207 cases (27.1%) with 2+ IHC score showed HER2 gene amplification while the majority of cases with 3+ IHC score were gene-amplified (446 out of 451, 98.9%).
CONCLUSION: ISH study should be done in all IHC-equivocal cases (2+) to select patient for targeted therapy. Gene amplification must also be confirmed in IHC-positive cases (3+) to prevent from giving non-effective treatment with possible adverse effects to patient with non-amplified HER2 gene.