A Rare Case of Post-Primary Tuberculosis Which Was Pathologically Diagnosed as Lipoid Pneumonia.

Case Presentation: The patient was a middle-aged housewife who had been using the household spray for a long time, and the main symptoms were cough and sputum production. Chest CT showed lobar ground-glass opacities (GGOs) with small patchy consolidation in the right middle lobe (RML), specifically, lung tissue pathology showed a large number of foamy cells and scattered multinucleated giant cells. The patient received empirical anti-infective treatment, but no clinical improvement was observed. Laboratory tests, including smears and cultures of sputum, blood and bronchoalveolar lavage fluid (BALF), did not provide clear evidence for pathogenic microorganisms. Therefore, the presumptive diagnosis was exogenous LP (ExLP). After 28 days of prednisone treatment, her symptoms improved, but 2 months later, she presented with a worsening cough, and the GGOs had progressed into lobar consolidation. Transbronchial lung biopsy (TBLB) culture showed mycobacterium tuberculosis (MTB), and lung tissue pathology showed granulomatous inflammation. After anti-tuberculosis treatment, the consolidation in the right middle lobe was gradually absorbed, along with a considerable symptom improvement. The final diagnosis of the patient was MTB infection with an endogenous lipoid pneumonia (EnLP)-like presentation. Conclusion: The current case highlights that the MTB infection should be considered when pathology shows LP accompanied by scattered multinucleated giant cells.