en Infectious Diseases Infectious Diseases case report case report <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:14pt"><b><i><span style="color:blue">Background:</span></i></b> The simultaneous involvement of the pleura and peritoneum with tuberculosis in the absence of pulmonary foci is an uncommon condition that may lead physicians to misdiagnose.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Case Presentation:</span></i></b> Herein, we present a Persian male adult who manifested with epigastric pain, weakness, and a history of pleuritic chest pain two months prior to admission. The findings of the physical examination included vital signs within the normal range, unilateral fine crackle in the lung, abdominal distension with positive shifting dullness, and fluid wave test. Analysis of the ascitic fluid revealed a Serum-ascites albumin gradient (SAAG) of less than 1.1g/dl, indicating a non-portal condition. The results of the acid-fast bacilli (AFB) staining as well as the TB polymerase chain reaction (PCR) test were negative. However, the adenosine deaminase (ADA) level was 44 IU/L. A chest CT scan revealed mediastinal lymph node enlargement and pleural thickening with loculated pleural effusion. Three acid-fast bacilli smear of morning sputum were sent, and all three were negative. An abdominopelvic CT scan showed multiple periaortic and mesenteric lymph nodes of varying sizes with mesenteric haziness and accumulation of effusion in the peritoneal cavity. Eventually, peritoneal biopsy, the gold standard, was performed, which revealed multiple granulomatous lesions and areas of caseous necrosis surrounded by Langerhans giant cells and epithelioid cells<span dir="RTL" lang="FA">.</span><span style="font-size:10.0pt"></span></span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Conclusion:</span></i></b><b> </b>It is worth noting that in cases of ascites and pleural thickening, especially in patients with poor socioeconomic status, simultaneous pleural and peritoneal TB should be considered, especially in third-world countries<span dir="RTL" lang="FA">.</span><span style="font-size:10.0pt"></span></span></span></span><br> &nbsp; Extrapulmonary, Tuberculosis, Pleural effusion, Ascites, Pleura, Peritoneum, case report, literature review 735 742 http://caspjim.com/browse.php?a_code=A-10-3107-1&slc_lang=en&sid=1 Elham Barahimi dr.e.barahimi@gmail.com 100319475328460050102 100319475328460050102 No Infectious and Tropical Diseases Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Zahra Ghaeini Hesarooeyeh zahraghaeini98@gmail.com 100319475328460050103 100319475328460050103 No Student Research Committee, Faculty of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Ayoub Basham ayoubbasham.research@gmail.com 100319475328460050104 100319475328460050104 Yes Student Research Committee, Faculty of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Mohadeseh Karimi mohadesehkarimi2318@gmail.com 100319475328460050105 0099-0007-8424-7754 No Department of Pathology, Faculty of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Behnoush Heidari b.heidari80@gmail.com 100319475328460050106 100319475328460050106 No Infectious and Tropical Diseases Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran