The utility of immunohistochemistry for detecting mycobacterial infections in bronchoalveolar lavage & bronchial washings.

Background & objectives: Tuberculosis, most commonly caused by Mycobacterium tuberculosis (MTB), is an infectious bacterial disease, with a major impact on global health. In this study, immunohistochemistry (IHC), acid-fast bacilli (AFB) culture and Ziehl-Neelsen (ZN) staining, techniques were compared on bronchoalveolar lavage (BAL) and bronchial washings (BW) with respect to sensitivity and specificity for detecting mycobacteria, taking culture as the gold standard. Methods: Consecutive BAL and BW specimens were included in the study, over a period of one year for which AFB cultures were available. Samples with diagnosis other than inflammatory pathology such as malignancies or inadequate samples were excluded. A total of 203 BAL and BW specimens from patients with age ranging from 14 to 86 yr were analyzed for the presence of mycobacteria. The utility and efficacy of ZN stain and IHC in detecting mycobacteria was tested using AFB culture as a gold standard. Results: Out of 203 cases, 10.3 per cent (n=21) were positive on AFB culture. Of these, 5.9 per cent (n=12) smears were positive for ZN stain, whereas IHC positivity was seen in 8.4 per cent (n=17) of the cases. ZN staining had a sensitivity of 57.1 per cent and a specificity of 100 per cent whereas, IHC had a sensitivity of 81 per cent and a specificity of 81.9 per cent. Interpretation & conclusions: Comparison with AFB culture (gold standard), IHC was found to be superior to ZN stain in terms of sensitivity, whereas ZN stain was found to be superior to IHC in terms of specificity. These findings therefore suggest that IHC may be a useful adjunct to ZN stain in the detection of mycobacteria in specimens from the respiratory tract.

Clinical and Cytological Spectrum of Granulomatous Mastitis and Utility of FNAC in Picking up Tubercular Mastitis: An Eight-Year Study.

INTRODUCTION: Granulomatous Mastitis (GM) is a rare, benign, inflammatory disease of the breast. It is a well known mimicker of malignancy, clinically and radiologically. Patients are often subjected to number of tests for the right diagnosis. Non-specific Granulomatous Mastitis (NGM) and Tubercular Mastitis (TBM) are chief among the various causes of GM. They are important to be diagnosed early as their treatment varies significantly. Fine Needle Aspiration Cytology (FNAC) is simple, patient friendly and primary investigation modality in cases of lump in breast. AIM: To find out the utility of FNAC in differentiating NGM and TBM. MATERIALS AND METHODS: All cases of granulomatous mastitis diagnosed on cytology over eight years were retrospectively retrieved. The clinical and radiological history was obtained from the patient file. The slides were stained with haematoxylin and eosin stain as well as Leishman stains. Special stains like Periodic Acid Schiff (PAS) and Ziehl Neelsen (ZN) stain were used for fungus and Mycobacteriumtuberculosis respectively. Histopathological correlation of the available cases was done. Clinical presentation and cytological morphology of individual cases was studied in detail. RESULTS: Twenty one cases of GM obtained, of which 16 were NGM and five were TBM. Both diseases were common among young reproductive women who presented with unilateral breast lump of varying duration. Almost 25% of NGM and 60% of TBM has clinical suspicion of malignancy. About 30% had radiological suspicion of malignancy. Nearly 62.5% of NGM patients had painful swelling and none of tubercular mastitis patients had pain. About 31% of NGM patients underwent prior abscess drainage and 40% of TBM patients gave history of tuberculosis. Almost 6.25% of NGM and 60% of TBM had axillary lymphadenopathy. Cytologically epithelioid cells were identified in 100% of patients whereas, granulomas were seen in 62.5% and 80% of NGM and TBM smears respectively. Langhans giant cells were frequent among TBM and foreign body giant cell among NGM. Caseous necrosis was seen in 60% of TBM and absent in NGM smears. CONCLUSION: Though, NGM and TBM is said to have overlapping features, our study highlights few clinical and cytological differences which aid in differentiating the two entities at primary level. FNAC along with special stain must be advocated as the primary tool of diagnosis in cases of GM.

Role of CD10 Immunoexpression in Grading Phyllodes Tumour of the Breast.

INTRODUCTION: Fibroepithelial tumours are a heterogeneous group of biphasic neoplasms consisting of a proliferation of both epithelial and stromal components. Fibroadenoma (FA) and Phyllodes Tumour (PT) constitute the major entities. It is crucial to distinguish benign from borderline PT (low grade malignant PT), because the former do not metastasize, have a lesser risk of local recurrence and initial local recurrences are histologically benign in almost all instances. Multiple Immunohistochemical (IHC) markers are being studied to find their utility in grading the PT accurately for planning proper treatment. AIM: To study, the IHC expression of CD10 in the stromal cells of a series of PTs and FA, with the aim of determining whether the degree of CD10 expression in the stromal cells is related to the grade of the tumour. MATERIALS AND METHODS: Records of 28 cases of PT and 35 cases of FA received in the Department of Pathology in a tertiary care hospital were obtained. Histopathology reports and slides of all the cases were reviewed and clinical data such as age and histomorphological features such as tumour cellularity, stromal overgrowth, mitotic count and nuclear atypia were noted. Representative block of the tumour with maximum cellularity was subjected to CD10 staining. For FA and benign PT a technique of tissue microarray was used. For borderline and malignant PT, representative section was used. Stromal cell staining was assessed, using cytoplasmic staining of the breast myoepithelium as internal control. RESULTS: Present study included 35 cases of FA, 20 cases of benign PT, five cases of borderline PT and three cases of malignant PT. The mean age of the patients increased with the increasing tumour grade of PT and this was also observed for FA and benign PT. The mean age increased with increase in tumour grade of PT and was statistically significant (p<0.05). The mean size did not increase with the increasing tumour grade of PT and was statistically insignificant (p=0.0429). Mean tumour size was more in benign PT as compared to FA and was highly statistically significant (p<0.01). CD10 staining was diffuse (Grade-3) and strong in malignant PT. The staining intensity was strong but patchy (Grade-2) in borderline PT. Weak and patchy (Grade-1) CD10 staining was seen in four benign PT and six FA. Other cases of benign PT and FA were negative for CD10 immunoreactivity. CONCLUSION: Our study showed that CD10 expression strongly correlates with the PT grade, which can help in the differentiation between benign and malignant variants of PT.