METHODS: Liquid based cervico-vaginal cytology specimens with squamous abnormalities and corresponding histology from 97 women with subsequent colposcopy and biopsy were included. The specimens were then subjected to the dual stain and Roche Cobas 4800 multiplex real time PCR HPV DNA testing. The sensitivity and specificity of the dual stain and HPV testing were calculated using CIN 2+ on histology as a reference standard.
RESULTS: The sensitivity and specificity of the dual stain in detecting histology proven CIN 2+ was 93.7% and 76.5% while HPV testing was 85.7% and 14.7% respectively. Of the 44 women with ASCUS or LSIL on cytology, the dual stain also reduced the number of unnecessary colposcopy referrals from 27 to 7 when used as a triage marker compared to HPV testing.
CONCLUSION: p16/Ki-67 dual stain was more sensitive and specific than HPV testing in determining the presence of CIN 2+ on histology. It could triage low grade cervico-vaginal specimens more effectively and potentially help women avoid unnecessary colposcopies. Future studies are needed to further evaluate its role in cervical cancer screening programmes.
MATERIALS AND METHODS: Immunohistochemical analysis of 60 thyroidectomy specimens (10 hyperplastic nodules, 14 follicular adenomas and 36 malignant thyroid neoplasms) was carried out. The extent and intensity of HBME-1, CK19, and S100 immunoreactivity was assessed in each case.
RESULTS: HBME-1 positivity was noted in 86.1% of malignant cases while the majority of the benign lesions were negative. Diffuse strong CK19 positivity was documented in 27/31 papillary carcinoma whereas all cases of follicular carcinoma and medullary carcinoma were negative. Most of the hyperplastic nodules and follicular adenomas were also CK19 negative, although focal weak staining was noted in a few cases. S100 was positive only in medullary carcinoma. HBME-1 was most sensitive (86.1%) and specific (87.5%) in distinguishing between benign and malignant thyroid lesions. The diagnostic accuracy was further increased when HBME-1 was used simultaneously with CK19/S100/CK19+S100. The sequential use of HBME-1 and CK19 also proved beneficial in discriminating between the various follicular-patterned thyroid lesions.
CONCLUSION: HBME-1 immunolabeling suggests malignancy, whereas strong diffuse CK19 positivity substantiates papillary differentiation. The utilization of these markers (alone or in combination) along with histomorphological evaluation is helpful in the differential diagnosis. S100 has minimal utility in this regard.
MATERIALS AND METHODS: 51 cases of DLBCL paraffin-embedded tissue samples were retrieved from a single private hospital in Kuala Lumpur, Malaysia. EBER-ISH was performed to identify the EBV expression; ten EBV(+)-DLBCL cases subjected to immunohistochemistry for LMP1, pJAK1, pSTAT3 and MYC; FISH assay for c-MYC gene rearrangement.
RESULTS: Among 10 cases of EBV(+)-DLBCL, 90% were non-GCB subtype (p=0.011), 88.9% expressed LMP1. 40% EBV(+)-DLBCL had pJAK1 expression.
CONCLUSION: 66.7% EBV(+)-DLBCL showed the positivity of pSTAT3, which implies the involvement of EBV in constitutive JAK/STAT pathway. 44.5% EBV(+)-DLBCL have co-expression of pSTAT3 and MYC, but all EBV(+)-DLBCL was absence with c-MYC gene rearrangement. The finding of clinical samples might shed lights to the lymphomagenesis of EBV associated with non-GCB subtypes, and the potential therapy for pSTAT3-mediated pathway.
MATERIALS AND METHODS: We collected 54 malignant and 65 benign thyroid lesions diagnosed by histology in Universiti Kebangsaan Malaysia Medical Centre between January 2010 and December 2015. All cases were immunohistochemically stained with CK 19 and evaluated by 3 independent observers. The immunostaining patterns were scored based on the intensity and proportion of staining and finally graded as negative, weak positive, moderate positive or strong positive. In addition, the immunostaining scores of the malignant cases were correlated with their TNM pathological tumour stages.
RESULTS: Cytokeratin 19 staining expression was higher in malignant than benign thyroid lesions (p < 0.001) which was most prominent among classical PTC. The four PTC cases that showed negative or weak staining were all follicular variant of PTC. Benign conditions were mostly negative or showed weak positivity. There was no correlation between CK 19 expression and TNM primary tumour stage (pT).
CONCLUSION: Cytokeratin 19 is a useful marker in differentiating malignant from benign thyroid conditions particularly the classical PTC, provided its interpretation is by correlation with morphology and takes into consideration the intensity and proportion of positive staining.
Objective: This study aims to determine inter-laboratory variation in HER2 IHC testing through a slide-exchange program between five main reference laboratories.
Method: A total of 20 breast carcinoma cases with different known HER2 expression and gene status were selected by the central laboratory in five testing rounds. Three unstained tissue sections from each case were sent to participating laboratories, which immunostained and interpreted the HER2 immunohistochemistry result. One of the stained slides was sent to one designated participating laboratory for evaluation. Results were analyzed by the central laboratory.
Results: A complete concordance was achieved in six IHC-positive and six IHC-negative cases, its gene status of which was confirmed by in-situ-hybridization (ISH) study. The discordant results were observed in six equivocal cases, one negative case and one positive case with a concordance rate of 50-88.3%. Interestingly, the negative discordant case actually displays tumor heterogeneity. Good inter-observer agreement was achieved for all participating laboratories (k = 0.713-1.0).
Conclusion: Standardization of HER2 testing method is important to achieve optimum inter-laboratory concordance. Discordant results were seen mainly in equivocal cases. Intra-tumoral heterogeneity may impact the final HER2 IHC scoring. The continuous quality evaluation is therefore paramount to achieve reliable HER2 results.