<sup>18</sup>FDG PET/CT is Sensitive but not Specific for Malignancy: Two Cases of Disseminated Tuberculosis Mimicking Metastatic Cancer on Imaging and Clinical Presentation

Introduction 18 Fluorodeoxyglucose positron emission tomography/computed tomography ( 18 FDG PET/CT) scan is widely used in the evaluation of suspected tumoral processes. In addition to its oncological applications, it is also employed in the diagnosis and follow-up of various conditions, including multiorgan tuberculosis. Case description We report a case series of two young patients with exclusive extrapulmonary disseminated tuberculosis that mimicked a neoplastic process both clinically and on 18 FDG PET/CT imaging. Initially, both patients were admitted to the oncology unit with a presumed diagnosis of cancer. However, following an exhaustive work-up, a definitive diagnosis of tuberculosis was established via histopathological and microbiological analysis. Conclusion These cases underscore the importance of considering disseminated tuberculosis as a differential diagnosis during oncologic evaluations, especially in patients from endemic regions, and highlight the potential psychological impact of prematurely labelling a condition as cancer. Learning points Extrapulmonary tuberculosis can mimic metastatic malignancies.Imaging does not replace pathology, which remains the gold standard for accurately diagnosing multiorgan involvement.Prematurely announcing a diagnosis of cancer before final confirmation can have significant psychological consequences.