Correlation between HER2/neu protein overexpression on Immunohistochemistry and Fluorescent in Situ Hybridization (FISH) in breast carcinoma: Problems in developing countries.

Objective: To correlate the results of HER2/neu protein overexpression on immunohistochemistry (IHC) and gene amplification on fluorescence in situ hybridization (FISH) and to document the problems faced in performing FISH procedure. Methods: This was an observational retrospective study covering five years from January 1st, 2015 - December 31st, 2019 at Histopathology Department of Shifa International Hospital (SIH), Islamabad. All cases of breast cancer that underwent florescence in situ hybridization (FISH) were retrieved. Correlation between HER2/neu overexpression on IHC and its amplification on FISH was analyzed. Problems in application of FISH were recorded. Results: Out of 451 cases submitted for HER2/neu testing by FISH, 68 cases (15%) were rejected. Gene amplification was seen in 139 (36.29%) cases. Total cases with HER2/neu IHC score of 2+ were 330 cases and out of which gene amplification was seen in 98 cases (29.69%) whereas 93.1% (41/44) 3+ IHC cases were amplified. Poor fixation, inadequate amount of tumor with crushing artefacts and dye application to the biopsy fragments were causes of sample rejection. Conclusions: Her2/neu amplification was seen in most Her2/neu 3+ cases and approximately one-third of Her2neu 2+ cases. Proper fixation, adequate biopsy material with standardized processing is required to yield useful results on FISH.

Microsatellite Instability in Endometrial Carcinoma by Immunohistochemistry, Association with Clinical and Histopathologic Parameters.

Objective: We aimed to investigate the frequency of microsatellite instability (MSI) in endometrial carcinoma in our population and its association with clinico-pathologic features. Methods: A total of 126 cases of primary endometrial carcinoma were included in the study that underwent surgical resections. All slides of these cases were reviewed and representative paraffin fixed tissue blocks were selected for MLH1, MSH2, MSH6 and PMS2 IHC staining. IHC expression was categorized into five groups: no loss of expression; loss of expression of all four antibodies; combined loss of MLH1/PMS2; combined loss of MSH2/MSH6; and isolated loss of MLH1. Pathological records of all cases were retrieved from patient files. Result: Abnormal expression of MSI was noted in 56 cases (44.4%) among which 16 cases showed loss of nuclear expression of all markers, 34 cases showed loss of MLH1/PMS2 expression, 4 cases showed loss of MSH2/MSH6 while only 2 cases revealed isolated loss of MLH. Personal and family history suggestive of inherited cancer susceptibility was revealed in 11 cases most of which were associated with MSH2/MSH6 loss. Significant association of MSI expression was found with tumor stage and personal/family history of endometrial/ colon cancer. Conclusion: A high frequency of endometrioid cancers in our study showed abnormal expression of MSI markers, most of which depicted MLH1/PMS2 loss and were not associated with inherited cancer susceptibility. On the other hand, a minority of cases showed loss of all MSI markers or MSH2/MSH6 loss and were significantly associated with family/personal history of cancer. Therefore, we suggest that epigenetic changes in MLH1 locus may be a predominant pathway of tumorigenesis in our population rather than inherited mutation of MSI genes; however more large scale studies with genetic testing are required to validate this observation.

Prognostic Significance of High Androgen Receptor Expression in Prostatic Acinar Adenocarcinoma

Background: Quantitative immunohistochemical expression of Androgen receptor (AR) has not been evaluated as a prognostic biomarker of prostate cancer in our population, therefore in the current study we aimed to evaluate the association of AR expression in prostatic acinar adenocarcinoma with various prognostic parameters like tumor quantification, Gleason score, WHO grade group and perineural invasion. Methods: Total 121 cases of biopsy proven prostatic acinar adenocarcinoma were selected from records of pathology department archives from January 2013 till December 2017. Hematoxylin and eosin stained slides and paraffin blocks were retrieved and new sections were cut where necessary. Slides of all cases were reviewed by two senior histopathologists and pathologic characteristics like Gleason score, WHO grade, tumor quantification, perineural and lymphovascular invasion were evaluated. Androgen receptor immunohistochemistry was applied on all cases. Results: Low AR expression was noted in 53 cases (43.8%) while high AR expression was seen in 68 cases (56.2%). Significant association of AR expression was noted with total Gleason score, WHO grade and percentage of tissue involvement (tumor quantification). Univariate binary logistic regression showed patients with low Gleason scores (scores 6,7 or 8) and low WHO grade (grade 1, 2 or 3) were less likely to express high AR expression in comparison to high Gleason score (score 9) and high WHO grade group (grade 5) respectively. Similarly, cases with low tissue involvement by carcinoma (<50%) were less likely to show high AR expression in comparison to cases with >50% tissue involvement by carcinoma. Conclusion: Significant association of AR expression was noted with total Gleason score, WHO grade and percentage of tissue involvement (tumor quantification) which are among the most important markers of tumor progression; therefore we suggest that AR expression should be performed in patients with prostatic adenocarcinoma for prognostic stratification of the patients.

Diagnostic accuracy of fine needle aspiration biopsy in pediatric small round cell tumors.

OBJECTIVE: Fine needle aspiration biospy (FNAB) is a simple, cost effective procedure, which can be carried out in the out-patient department. The objective of our study was to determine the diagnostic accuracy of fine needle aspiration biopsy in small round cell tumors of childhood, keeping histopathology as the gold standard. RESULTS: Out of these 50 cases, 35 (70%) were small round cell tumors and 15 (30%) cases of other childhood malignancies and certain reactive conditions. In our study, the most common malignant small round cell tumor (SRCT) on histopathology was Wilms tumor (10 cases) followed by non Hodgkin lymphoma (9 cases). FNAB results were correlated with the histological findings and the diagnostic accuracy of SRCT came out to be 98%. The sensitivity and specificity of FNAB in diagnosing SRCT was 97% and 100% respectively. FNAB was found to be a very useful technique in the initial evaluation of any palpable lesion of childhood. Although the small round cell tumors appear cytologically similar, in the hands of experienced cytopathologists, the subtle morphological features can help towards the final diagnosis. In addition, clinical and radiological findings are invaluable assets, which help to reach the final diagnosis.

Diagnostic accuracy of touch imprint cytology for head and neck malignancies: a useful intra-operative tool in resource limited countries.

BACKGROUND: Intraoperative consultation is an important tool for the evaluation of the upper aerodigestive tract (UAT) malignancies. Although frozen section analysis is a preferred method of intra-operative consultation, however in resource limited countries like Pakistan, this facility is not available in most institutes; therefore, we aimed to evaluate the diagnostic accuracy of touch imprint cytology for UAT malignancies using histopathology of the same tissue as gold standard. METHODS: The study involved 70 cases of UAT lesions operated during the study period. Intraoperatively, after obtaining the fresh biopsy specimen and prior to placing them in fixative, each specimen was imprinted on 4-6 glass slides, fixed immediately in 95% alcohol and stained with Hematoxylin and Eosin stain. After completion of the cytological procedure, the surgical biopsy specimen was processed. The slides of both touch Imprint cytology and histopathology were examined by two consultant histopathologists. RESULTS: The result of touch imprint cytology showed that touch imprint cytology was diagnostic in 68 cases (97.1%), 55 (78.6%) being malignant, 2 cases (2.9%) were suspicious for malignancy, 11 cases (15.7%) were negative for malignancy while 2 cases (2.9%) were false negative. Amongst the 70 cases, 55 cases (78.6%) were malignant showing squamous cell carcinoma in 49 cases (70%), adenoid cystic carcinoma in 2 cases (2.9%), non-Hodgkin lymphoma 2 cases (2.9%), Mucoepidermoid carcinoma 1 case (1.4%), spindle cell sarcoma in 1 case (1.4%). Two cases (2.9%) were suspicious of malignancy showing atypical squamoid cells on touch imprint cytology, while 13 cases (18.6%) were negative for malignancy, which also included 2 false negative cases. The overall diagnostic accuracy of touch imprint cytology came out to be 96.7% with a sensitivity and specificity of 96 and 100%, respectively while PPV and NPV of touch imprint cytology was found to be 100 and 84%, respectively. CONCLUSION: Our experience in this study has demonstrated that touch imprint cytology provides reliable specific diagnoses and can be used as an adjunct to histopathology, particularly in developing countries, where the facility of frozen section is often not available, since a rapid preliminary diagnosis may help in the surgical management planning.