Clinical Significance of BCL2, C-MYC, and BCL6 Genetic Abnormalities, Epstein-Barr Virus Infection, CD5 Protein Expression, Germinal Center B Cell/Non-Germinal Center B-Cell Subtypes, Co-expression of MYC/BCL2 Proteins and Co-expression of MYC/BCL2/BCL6 Proteins in Diffuse Large B-Cell Lymphoma: A Clinical and Pathological Correlation Study of 120 Patients

Background: Clinical significance of germinal center B-cell (GCB) and non-GCB sub-categorization, expression of MYC, BCL2, BCL6, CD5 proteins and Epstein Barr virus encoded RNA (EBER) positivity in diffuse large B-cell lymphoma (DLBCL) remain controversial. Could these biomarkers accurately identify high risk DLBCL patients? Are MYC, BCL2 and BCL6 proteins expression feasible as baseline testing to predict c-Myc, BCL2 or BCL6 gene rearrangements? Aims: To investigate prognostic values of GCB/non-GCB sub-categorization, Double Protein Expression Lymphoma (DPL), Triple Protein Expression Lymphoma (TPL), positivity of CD5 protein and EBER in patients with DLBCL disease. To evaluate correlation between BCL2 , c-Myc and BCL6 gene rearrangements with BCL2, MYC and BCL6 proteins expression. Methods: Diagnostic tissue samples of 120 DLBCL patients between January 2012 to December 2013 from four major hospitals in Malaysia were selected. Samples were subjected to immunohistochemical staining, fluorescent in-situ hybridization (FISH) testing, and central pathological review. Pathological data were correlated with clinical characteristics and treatment outcome. Results: A total of 120 cases were analysed. Mean age of diagnosis was 54.1 years ± 14.6, 64 were males, 56 were females, mean follow up period was 25 months (ranged from 1 to 36 months). Of the 120 cases, 74.2% were non-GCB whereas 25.8% were GCB, 6.7% were EBER positive, 6.7% expressed CD5 protein, 13.3% were DPL and 40% were TPL. The prevalence of c-Myc, BCL2, BCL6 gene rearrangements were 5.8%, 5.8%, and 14.2%, respectively; and 1.6% were Double Hit Lymphoma (DHL). EBER positivity, DPL, TPL, c-Myc gene rearrangement, BCL2 gene rearrangement, extra copies of BCL2 gene and BCL6 gene rearrangement were associated with shorter median overall survival (P<0.05). IPI score was the significant determinants of median overall survival in DPL and TPL (P<0.05). CD5 protein expression and GCB/non-GCB sub-categorization did not affect treatment outcome (P>0.05). Overall, c-Myc, BCL2 and BCL6 gene rearrangements showed weak correlation with expression of MYC, BCL2 and BCL6 proteins (P>0.05). Fluorescent in situ hybridization is the preferred technique for prediction of treatment outcome in DLBCL patients. Conclusion: c-Myc, BCL2, and BCL6 gene rearrangements, EBER expression, DHL, TPL and IPI score are reliable risk stratification tools. MYC, BCL2 and BCL6 proteins expression are not applicable as baseline biomarkers to predict c-Myc, BCL2, and BCL6 gene rearrangements.

Co-expression of MYC and BCL2 in diffuse large B-cell lymphoma

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common type of nonHodgkin lymphoma. The pathogenesis of DLBCL is complex because it involves at least two different pathways, a de novo pathway and a transformation pathway. MYC and BCL2 oncogenes are 2 key regulators implicated in the pathogenesis. DLBCL with concurrent expression of MYC and BCL2 has been shown to be clinically aggressive and confers a worse prognosis. MYC detection by immunohistochemistry is however not performed in a routine diagnostic work up of DLBCL cases. This study examined the presence of MYC and BCL2 proteins by immunohistochemistry in patients diagnosed to have DLBCL. Methods: This retrospective study involved patients diagnosed to have DLBCL at Tengku Ampuan Afzan Hospital, Kuantan, Pahang (Year 2009-2011) and Queen Elizabeth Hospital, Kota Kinabalu, Sabah Malaysia (Year 2012-2014). Immunohistochemistry for MCY and BCL2 were performed on sections of formalin fixed paraffin embedded tissue blocks. Results: There were 91 cases analyzed. Forty-nine cases (53.8%) exhibited concurrent expression of MYC and BCL2 proteins. In about one third of the cases, positivity was confined to BCL2. In 4 cases (4.4%) only MYC was expressed while in 9 cases (9.9%) both markers were negative. Overall about 60% and 85% of the cases were positive for MYC and BCL2 respectively. Conclusions: Approximately half of DLBCL case studied co-express MYC and BCL2. Prospective studies to look at the clinical significance and prognostic impact of this finding are advocated.

Diagnostic flex-rigid pleuroscopic biopsy of parietal pleura for exudative pleural effusions in suspected malignant and tuberculosis cases: a retrospective study of 219 cases

OBJECTIVES

This study was carried out to ascertain the aetiology of exudative pleural effusions when other diagnostic investigations such as pleural fluid and sputum examination for cytology and acid fast bacilli fail to yield a definitive diagnosis and to differentiate between tuberculosis and malignancy in cases suspicious of malignancy.

METHODS

Pleuroscopic biopsies were obtained in 219 cases by Chest Physicians in the endoscopy suite using flexi-rigid fiber-optic pleuroscopes. Histological sections were stained with H&E and microscopic examination performed. Ziehl-Nielsen stain for acid fast bacilli was performed in all suspected tuberculosis cases and immunohistochemistry for Thyroid transcription factor 1 and other markers were carried out for all cases suspicious of malignancy.

RESULTS

Adequate biopsy material for interpretation was obtained in 210 (95.9%) of 219 cases. Histopathology revealed 79 (37.6%) cases were tuberculosis, 64 (30.5%) were malignant (primary from lung and other sites), 62 (29.5%) were non-specific inflammation and 5 (2.4%) were empyema. A definitive diagnosis of tuberculosis, malignancy and empyema was obtained in 70.5% of cases. Tuberculosis was encountered in a younger age-group than malignancy. Mean age for tuberculosis patient was 49 years while for malignant patients was 63 years. The majority (79.6%) of malignances encountered were metastatic lung adenocarcinoma.

Expression distribution of cancer stem cells, epithelial to mesenchymal transition, and telomerase activity in breast cancer and their association with clinicopathologic characteristics

A total of 167 surgically resected primary invasive breast carcinomas and 63 metastatic lymph node lesions were analyzed for immunohistochemical (IHC) localization of the CD44⁺CD24^−low breast cancer stem cell (CSC) markers, epithelial to mesenchymal transition (EMT) markers, and telomerase activity by double-staining IHC technique, in formalin-fixed, paraffin-embedded tissue, the results were validated by double-staining immunofluorescent and flow cytometry techniques. The results showed that CSCs with CD44⁺CD24^−low phenotype were significantly increased in node-positive tumors, high-grade tumors, and ductal carcinoma in situ (DCIS). There was a high incidence of telomerase expression in metastatic lymph node lesion. There were considerably high number of tumor cells with EMT expression in metastatic lymph node lesion, and triple-negative tumor. The occurrence of EMT phenomena was usually accompanied by the co-existence of CSCs of CD44⁺CD24^−low phenotype. There was no association between the existence of CSCs and detection of telomerase activity in tumor cells. Increased numbers of both CSCs of CD44⁺CD24^−low phenotype and cells underwent EMT in DCIS lesion might be an initial step in the stromal invasion and propagation of breast cancer, and occurrence of EMT in the breast tumor associated with high prevalence of CSCs, promoting tumor invasiveness and metastasis.

Acute glomerulonephritis in Kelantan--a prospective study

A prospective study of acute nephritis in children was conducted at the Universiti Sains Malaysia Hospital, Kubang Kerian between July 1987 and June 1988. One hundred and twenty four children were admitted with acute glomerulonephritis. The aim of the study was to determine the clinical pattern of the nephritis as well as its aetiology. The majority of our patients came from the lower socio-economic group and 54% of the families had incomes below the poverty line. Preceding skin infection was much more common than throat infection. The children showed a high incidence of complications: severe hypertension (43.6%), hypertensive encephalopathy (11.3%), clinical pulmonary oedema (36.3%), severe azotaemia (10.5%), and prolonged gross haematuria (13.7%). By using immunologic indices such as ASOT, anti-DNase B and complement 3, it was concluded that 121 of the 124 patients had post-streptococcal nephritis.