RESUMO
BACKGROUND: Tuberculous peritonitis often presents with nonspecific symptoms that can lead to diagnostic challenges, particularly when manifesting as peritoneal pseudocysts. This study highlights the clinical complexity and diagnostic approach of tuberculous peritonitis presented as a pseudocyst in an immunocompetent adult, an atypical scenario that is rarely documented. CASE PRESENTATION: We report a detailed case of a 41-year-old man presenting with abdominal distension, pain, and significant weight loss over four months. Abdominal CT showed a peritoneal pseudocyst, initially misdiagnosed due to its resemblance to more common abdominal pathologies. The diagnosis of tuberculous peritonitis was confirmed through histopathological analysis. Additionally, a systematic literature review was conducted to identify and analyse similar cases, focusing on clinical presentations, diagnostic methods, and patient outcomes. Our patient exhibited classic symptoms of abdominal TB but was unique due to the absence of prior ventriculoperitoneal shunting, a common factor in similar cases. Our literature review found that such presentations typically result in diagnostic delays averaging five months, complicating patient management and outcomes. This review also underscores the importance of considering tuberculosis in the differential diagnosis of peritoneal pseudocysts, particularly in TB-endemic regions. CONCLUSION: This case and review emphasize the need for high clinical suspicion and prompt investigation of tuberculosis in patients presenting with atypical abdominal symptoms and pseudocysts. Improved diagnostic strategies, including early use of imaging and pathological evaluations, are essential for timely diagnosis and management, thereby improving patient outcomes in suspected cases of extrapulmonary tuberculosis.