Immunocytochemistry versus nucleic acid amplification in fine needle aspirates and tissues of extrapulmonary tuberculosis

Background: Immunocytochemistry (ICC) is an established routine diagnostic adjunct to cytology and histology for tumor diagnosis but has received little attention for diagnosis of tuberculosis. Aims: To have an objective method of direct visualization of mycobacteria or their products in clinical extrapulmonary tuberculosis (EPTB) specimens, immunocytochemical localization of M. tuberculosis antigen by staining with species specific monoclonal antibody to 38-kDa antigen of Mycobacterium tuberculosis complex. Materials and Methods: Immunostaining with specific monoclonal antibody to 38-kDa antigen of Mycobacterium tuberculosis complex was done in fresh and archival fine needle aspirates and tissue granulomata of 302 cases of extrapulmonary tuberculosis and was compared with the molecular diagnostic i.e., nucleic amplification and conventional [Cytomorphology, Ziehl Neelsen (ZN) staining and culture] tests and 386 controls. Results: Diagnostic indices by Bayesian analysis for all types of archival and fresh material varied from 64 to 76% in nucleic acid amplification (NAA) and 96 to 98% in ICC. There was no significant difference in the diagnostic indices of ZN staining and/ or ICC in fresh or archival material whereas the sensitivity of NAA differed significantly in fresh versus archival material both in cytology (71.4% vs 52.1%) and histology (51.1% vs 38.8%). ICC can be easily used on archival smears and formalin-fixed paraffin-embedded tissue sections with almost equal sensitivity and specificity as with fresh material, in contrast to NAA which showed significant difference in test results on archival and fresh material. Conclusions: Low detection sensitivity of MTB DNA in archival material from known tuberculous cases showed the limitation of in-house NAA-based molecular diagnosis. ICC was found to be sensitive, specific and a better technique than NAA and can be used as an adjunct to conventional morphology and ZN staining for the diagnosis of EPTB in tissue granulomas

Rare case of gastrointestinal stromal tumor of the anal canal

Gastrointestinal stromal tumor (GIST) is a rare mesenchymal neoplasm of the gastrointestinal tract. GIST of anal canal is very rare representing only 3% of all anorectal mesenchymal tumors. We report an extremely rare case of GIST of the anal canal in 60-years-old man with history of irregular bowel habits with dark colored stool mixed with blood and constipation from 6 month. Diagnosis was made on the basis of histomorphological and immunohistochemical examination

Comparative study between liquid-based cytology & conventional Pap smear for cytological follow up of treated patients of cancer cervix

Background & objectives: Cancer cervix is one of the most common forms of genital malignancy among Indian women. Recurrence is seen in a significant number of cases. The conventional cervical smear technique has inherent problems and screening and interpretation errors. This study was undertaken to assess the efficacy of liquid-based cytology (LBC) as a method for cytological follow up and detection of recurrence in treated cases of cancer cervix and to compare it with conventional Pap smear technique to find the best screening method for detection of recurrence in these patients. Methods: This cross-sectional study was conducted over a period of one year. Patients attending Gynecology and Radiotherapy outpatient departments for follow up after treatment of cancer cervix were included. Pap smear and LBC were taken in all cases. Colposcopy and biopsy were done for those having epithelial cell abnormality in cytology report. Colposcopy and biopsy were taken as gold standard for diagnosis of cancer cervix recurrence. Results: Ninety four treated patients of carcinoma cervix were studied. The diagnostic accuracy for detection of recurrence of conventional Pap smear was 79.16 per cent, and that of LBC was 97.6 per cent. The difference between the two methods was significant (P<0.001). Interpretation & conclusions: Our findings showed that LBC performed better than the conventional method of cytology to detect recurrence of squamous cell carcinoma. Its sensitivity, specificity as well as accuracy were much higher than conventional method. LBC can be a better method of cytological follow up of post-treated patients of cancer cervix