Open Access Maced J Med Sci. 2021 Aug 17; 9(A):579-582. 579 Scientifc Foundation SPIROSKI, Skopje, Republic of Macedonia Open Access Macedonian Journal of Medical Sciences. 2021 Aug 17; 9(A):579-582. https://doi.org/10.3889/oamjms.2021.6239 eISSN: 1857-9655 Category: A - Basic Sciences Section: Microbiology Agreement Test of Histopathology in the Diagnosis of Extrapulmonary Tuberculosis with Gold Standard Polymerase Chain Reaction Technique: A Step to Overcome False Diagnosis Ali Essa Shaker 1 , Mohammed Abdulmahdi Al Kurtas 2 , Haider Zalzala 3 * 1 Department of Family Medicine, Ministry of Health, Baghdad, Iraq; 2 Department of Pathology, University of Baghdad, Al-kindy College of Medicine, Baghdad, Iraq; 3 HLA Typing Research Unit, University of Baghdad, Al-kindy College of Medicine, Baghdad, Iraq Abstract BACKGROUND: Tuberculosis (TB) is global health problem which is caused by Mycobacterium tuberculosis (M. tuberculosis) bacteria. One-quarter of the world’s populations is infected by M. tuberculosis and only 10–15% of those develop the disease, while the remaining 85–95% of the population are carrying the bacteria and cannot transmit the disease to the others. M. tuberculosis bacteria afects the lungs, but any organ in the body can be afected by the bacteria. About 15% of M. tuberculosis infections are of in the extrapulmonary type. The diagnosis of extrapulmonary TB (EPTB) is very challenging because most sites are inaccessible and paucibacillary nature of the bacteria in these sites. The need for rapid and more sensitive and specifc tests for the diagnosis of EPTB in comparison to culture and histopathology is increasing. The molecular methods for the detection of M. tuberculosis gene(s) in the provided sample are now promising. PATIENT AND METHODS: A cross-sectional descriptive study at AL-Kindy Teaching Hospital at Al-Resafa part of Baghdad city, Iraq. Data collection has been done in three months duration (July, August, and September) 2015. A total of 74 formalin-fxed parafn-embedded samples from suspected EPTB cases was collected, both Polymerase Chain reaction test for M. tuberculosis and histopathological examination was done for each sample. RESULTS: A total of 74 patients (18 males, 56 females), mean age 29.72 suspected to had extrapulmonary TB underwent biopsies from diferent tissue types. The biopsies from the 74 patients were taken from diferent tissues according to the site of lesion, 49 (66.2%) biopsies were taken from lymph node, 12 biopsies (16.2%) was taken from mass in the axilla, 6 (8.1%) from abscess, 4 (5.4%) from the intestine, 3 (4.1%) from fstula. Of the 74 studied patients 57 (77%) showed positive polymerase chain reaction (PCR) and 17 (23%) showed negative PCR results. Regarding to the histopathological reports of the biopsies, there were 54 (73%) patients had positive histopathological (granuloma) result and 20 (27%) patients had negative results (nongranuloma). The sensitivity of histopathological examination of the biopsies was 91.02%, the specifcity 88.2%, and the kappa was 0.748 (p = 0.00) which is mean good agreement between histopathological examination of the biopsies and the polymerase chain reaction test. CONCLUSIONS: The sensitivity, specifcity, and the positive predictive value of histopathology examination of biopsies were 91.02%, 88.2%, and 96%, respectively. The kappa was 0.748 (p = 0.00) which is mean good agreement between histopathological examination of the biopsies and the polymerase chain reaction test. Edited by: Slavica Hristomanova-Mitkovska Citation: Shaker AE, Al Kurtas MA, Zalzala H. Agreement Test of Histopathology in the Diagnosis of Extrapulmonary Tuberculosis with Gold Standard Polymerase Chain Reaction Technique: A Step to Overcome False Diagnosis Indonesia. Open Access Maced J Med Sci. 2021 Aug 17; 9(A):579-582. https://doi.org/10.3889/oamjms.2021.6239 Key words: Extrapulmonary tuberculosis; Molecular diagnosis; Polymerase chain reaction *Corresponding author: Haider Hashim Zalzala, University of Baghdad, Al-kindy College of Medicine, HLA Typing Unit, E-mail: haiderhashim@kmc.uobaghdad.edu.iq Received: 27-Apr-2021 Revised: 02-Aug-2021 Accepted: 07-Aug-2021 Copyright: © 2021 Ali Essa Shaker, Mohammed Abdulmahdi Al Kurtas, Haider Zalzala Funding: This research did not receive any fnancial support Competing Interest: The authors have declared that no competing interest exists Open Access: This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial 4.0 International License (CC BY-NC 4.0) Introduction Tuberculosis (TB) is a global health problem which is caused by Mycobacterium tuberculosis bacteria. It has been stated that one-quarter of the world’s populations is infected by TB and only 10–15% of those develop the disease, while the remaining 85–95% of the population are carrying the bacteria and can’t transmit the disease to the others. Ten millions will be ill every year most of them from low and middle-income countries and 1.5 millions die every year according to the WHO report [1]. M. tuberculosis bacteria afects the lungs, but any organ in the body can be afected by the bacteria. About 15% of TB infections are of in extrapulmonary type [1]. The most common sites for extrapulmonary tuberculosis (EBTB) are lymph nodes and pleura although other sites such as meninges, bones, intestines, and any other organs may be afected [2], [3]. The diagnosis of EPTB is very challenging because most sites are inaccessible and paucibacillary nature of the bacteria in these sites. Negative smear form acid-fast bacilli and absence of granuloma in histopathology and negative results from TB culture do not exclude the diagnosis [4]. The need for rapid and more sensitive and specifc tests for the diagnosis of EPTB in comparison to culture and histopathology is increasing. Several attempts were tried such as the detection of adenosine deaminase detection in serum or efusion fuids but showed variable results [5], [6]. The molecular methods for the detection of TB gene(s) in the provided sample are now promising. In addition, many researches are published for this aspect with variable results [7], [8]. Some manufacturers tried to innovate a method for simultaneous detection of TB genes and the resistance