TB Research

18FDG PET/CT is sensitive but not specific for malignancy: two cases of disseminated tuberculosis mimicking metastatic cancer on imaging and clinical presentation

Maxime Collin, Bruno Krug, Marie‐Cécile Nollevaux, Fanny Collette, Quentin Gilliaux, Laurence Faugeras, Lionel D’Hondt

European Journal of Case Reports in Internal Medicine · 2025-06

Abstract

Introduction: 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: 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.

MeSH terms

  • Medicine
  • Malignancy
  • Presentation (obstetrics)
  • Tuberculosis
  • Cancer
  • Radiology