Programmed Death Ligand -1 and Gene Mutation Characterization of Lung Malignancies in Patients at a Rural Hospital in Central India.

INTRODUCTION: Lung malignancy is one of the most common neoplasms worldwide. Accurate histology sub-typing and identification of gene mutations in lung tumours are considered important to administer targeted therapy for improved clinical outcome. Our aim is to determine the frequency of EGFR mutation and Programmed death ligand-1 (PD -L1) status of lung malignancies in patients attending a rural hospital in Central India. MATERIALS AND METHODS: Formalin-fixed histology diagnosed lung malignancy (n=99) bronchoscopic/trucut lung biopsies were identified and the tissue blocks and slides were retrieved. Histology typing and staging of the lesions was assessed. PD-L1 expression on biopsy was detected by immunohistochemistry using commercially available primary antibody. PD-L1 expression was assessed and semi-quantified based on the intensity and proportion of tumour cells stained for the marker. EGFR gene mutation at exon19 and 21 was detected by polymerase chain reaction of tissue from paraffin blocks. Final analysis was performed on 87 biopsies for status of EGFR mutation and PD-L1 expression. RESULTS: The average age of lung malignancies patients was 63 years, with a preponderance of males. Advance disease in stage III and stage IV was more common in squamous cell carcinoma as compared to adenocarcinoma (p < 0.01). Mutations at exon 19-21 of the EGFR gene were detected in 7/87 (8%) cases of adenocarcinoma and all of these patients were non-smokers. A total of 52.9% of biopsies showed PD-L1 expression, which was higher in adenocarcinoma patients (p=0.04), smokers (p=0.00), and stage II and III patients (p= 0.00). CONCLUSION: EGFR gene mutations at exon 19 or 21 are seen in lung adenocarcinoma cases. PD-L1 expression was observed in EGFR mutated tissues. Our results should be further validated with large sample size and multicenter clinical data before extrapolation to design immunotherapy strategies.

Significance of non-granulomatous cytomorphology on fine needle aspirate in lymphadenitis cases classified as tuberculous by using a composite reference standard.

BACKGROUND: Fine needle aspiration cytology (FNAC) is established as a first line investigation for tuberculous lymphadenitis (TBLA). We aimed to describe the various cytomorphologic features of tuberculosis (TB) on FNAC and their contribution in the diagnostic decision-making in suspected TBLA cases. METHODS: Patients with presumptive TBLA were prospectively enrolled (n = 266) and subjected to routine diagnostic work-up for TB, including FNAC samples, and followed until the end of treatment. Patients were categorized as TB or non-TB cases based on a composite reference standard of which the various cytomorphologic patterns were compared. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy was calculated using cross-tabulation. RESULTS: Fifty-six patients were categorized as bacteriologically confirmed TB, 102 as clinically confirmed TB and 108 as non-TB. The most common cytomorphologic pattern among TB cases (59%) was granulomatous inflammation with necrosis, however, about one-third of tuberculous lymphadenitis patients presented with non-granulomatous inflammation, with 21% showing only necrosis and 13% presenting with a reactive pattern. The overall sensitivity and specificity of FNAC was 85% and 66%, respectively. CONCLUSIONS: We found that about one-third of TBLA patients presented without granulomas on FNA, highlighting the importance of considering TB in a wide spectrum of cytomorphology in a high TB burden setting. Our study supports the use of FNAC as a first-line investigation tool for diagnosing TBLA in a low-resource setting due to its relative simplicity and good sensitivity. However, the low specificity of FNAC, emphasizes the need for a second-tier confirmatory test with improved specificity.

Squash cytology in neurosurgical practice: a useful method in resource-limited setting with lack of frozen section facility.

BACKGROUND: Intra-operative cytology is an important diagnostic tool. It has shown to play an important role especially in the diagnosis of central nervous system tumours. The study was done to assess the feasibility of squash cytology as standalone diagnostic test in setting where frozen section facility is not available. MATERIALS AND METHODS: Total 48 patients with various intracranial lesions were initially enrolled in the study. Patients were investigated by various radio-imaging techniques and routine blood investigations. Forty-one patients were operated at Netaji Subhash Chandra Bose medical college, Jabalpur. Intra-operative squash cytology diagnosis was performed and was correlated with histology diagnosis as gold standard. RESULTS: Out of 41 patients, inflammatory lesions were diagnosed in nine patients while benign lesions [most common neurilemmoma and meningioma] were observed in 21 and malignant lesions [astrocytoma was most common] were diagnosed in 11 patients. Diagnostic accuracy of intra-operative squash cytology irrespective of lesion & site was 95%. We were able to inform about the diagnosis to neurosurgeon in 15 minutes in all cases and within 12 minutes in >85% cases CONCLUSION: Squash smear cytology is reliable and rapid standalone diagnostic method and it can assist for intra-operative decision-making diagnosis of intracranial lesions in resource-limited settings where frozen section facility is not available.

Rapid diagnosis of tuberculosis in aspirate, effusions, and cerebrospinal fluid by immunocytochemical detection of Mycobacterium tuberculosis complex specific antigen MPT64.

The aim of the study was to evaluate the diagnostic potential of immunocytochemical staining for the detection of Mycobacterium tuberculosis complex-specific antigen MPT64, in tuberculous lymph node aspirates, cerebrospinal fluid, and effusions from pleura and abdomen. One hundred ninety patients with a diagnosis of tuberculosis (cases) and 80 patients with nontuberculous lesions (controls) were enrolled and differentiated on the basis of clinical features, histology, cytology, clinical biochemistry, Ziehl-Neelsen staining, Lowenstein-Jensen culture, and response to antituberculous therapy. Cervical lymph nodes fine-needle aspirate (n = 150), cerebrospinal fluid (n = 27), pleural fluid (n = 41), and peritoneal fluid (n = 52) were collected and stained with anti-MPT64 and anti-BCG antibodies using immunocytochemistry. Nested-PCR for IS6110 was done for comparison and to calculate the diagnostic indices of the ICC staining. ICC staining with anti-MPT64 was positive in 128/190 (67.4%) tuberculous smears and in 4/80 (5%) control smears thus giving sensitivity of 67.4% and the specificity of 95%, while anti-BCG was positive in 112 (58.9%) tuberculous smears and in 16/80 (20%) control smears with sensitivity of 58.9% and specificity of 80%. When diagnostic validation of ICC was done using PCR as the gold standard, the overall sensitivity, specificity, positive- and negative-predictive values for ICC staining in smears with anti-MPT64 was 96, 96, 95, and 97%, respectively, while the corresponding values for anti-BCG were 87, 88, 86, and 88%. ICC staining using anti-MPT64 represents a robust and simple method for establishing an early etiological diagnosis of M. tuberculosis complex infection in extrapulmonary tuberculosis.

Detection of Mycobacterium tuberculosis by polymerase chain reaction with DNA eluted from aspirate smears of tuberculous lymphadenitis.

We have developed and evaluated a polymerase chain reaction (PCR) assay suitable for the detection of Mycobacterium tuberculosis DNA from fine needle aspirate smears of patients with tuberculous lymphadenitis. Air-dried fine needle aspirates of cervical lymph nodes from 98 patients with tuberculous lymphadenitis were studied for cytomorphology, detection of acid fast bacilli by Ziehl-Neelsen staining, culture and nested PCR with IS6110 for mycobacteria on DNA eluted from the dried unstained cytology smear. Twenty aspirate smears with diseases other than tuberculosis were similarly tested as controls. Mycobacterial-DNA was amplified by PCR in 84 (85%) cases and in 1 (5%) control. The mycobacteria could be detected by Ziehl-Neelsen stain and culture in 15 (15.3%) and 24 (24.4%) cases, respectively, whereas both tests were negative in controls. When results were compared with nested PCR on DNA from biopsies from the same case as the gold standard, the sensitivity, specificity, positive and negative predictive values of smear PCR were 85%, 95%, 96%, and 59%, respectively. In conclusion, PCR using dried cytology smear material is feasible and is a simple and sensitive technique for an early and specific diagnosis of M. tuberculosis complex. This is particularly useful when cytology is equivocal and can obviate the use of more invasive procedures.