Advertisement

Recurrent and persistent pneumonia

Published:February 02, 2018DOI:https://doi.org/10.1016/j.ejim.2017.12.018
      A 60-year-old man presented to our department for investigation of pulmonary opacity detected by Chest Computed Tomography (CT) at medical checkup. He had no clinical symptoms. Chest CT revealed a non-specific infiltrate with linear shadow in right upper lobe (Fig. 1: panel A), regarded as an old inflammatory change, and carefully observed. However, the shadow became larger, and, new lesions appeared in other lobes. All substances the could cause pneumonia were avoided at that time. However, the infiltrate persisted and became larger, and abnormal uptake of FDG was found at three months after avoiding ongoing exposure (Fig. 1: panel B). Lung malignancy including lung cancer could not be excluded, hence, to make a definite diagnosis, surgical biopsy was performed.
      Fig. 1
      Fig. 1A: Chest CT at presentation. B: P T2 T CT at three months after avoiding ongoing exposure. C:Oil Red staining of biopsy specimen.

      1. Diagnosis: exogenous lipoid pneumonia (ELP)

      Biopsy specimen revealed marked accumulation of lipid-laden macrophages in the alveolar space (Fig. 1: panel C), confirming the diagnosis of ELP.
      ELP is a rare condition caused by aspiration of oil substances [
      • Laughlen G.F.
      Studies on pneumonia following naso-pharyngeal injections of oil.
      ]. Lipid-laden macrophages in alveolar space is a characteristic pathology of ELP, essential for definite diagnosis. Radiographic findings in ELP are usually too non-specific to be of diagnostic value, hence, it is sometimes difficult to suspect and diagnose ELP [
      • Betancourt S.L.
      • Martinez-Jimenez S.
      • Rossi S.E.
      • Truong M.T.
      • Carrillo J.
      • Erasmus J.J.
      Lipoid pneumonia: spectrum of clinical and radiologic manifestations.
      ].
      ELP usually improves after avoiding ongoing exposure. However, in this case, according to the precise medical interview, exogenous lipoid pneumonia (ELP) was suspected before biopsy. (He had used petrolatum ointment as an intranasal application.), and intranasal use of the ointment was inhibited. However, the lung lesion of ELP was persistent and even progressive without any additional exposures, making diagnosis of ELP difficult. Organization and prolonged immunoreactions to the oil substances might contribute to persistent and progressive ELP despite avoiding ongoing exposure, although we could not elucidate the precise mechanism of prolonged ELP.
      It is important to consider ELP in the differential diagnosis of persistent and recurrent pneumonia because ELP is easily overlooked without intensive medical interview. In addition, since ELP can be progressive without ongoing exposure, careful observation for lung lesions is necessary even after avoiding causal agent in suspected cases. If clinical course is not typical, surgical or bronchoscopic biopsy is necessary to make a definite diagnosis.

      References

        • Laughlen G.F.
        Studies on pneumonia following naso-pharyngeal injections of oil.
        Am J Pathol. 1925 Jul; 1: 407-414.1
        • Betancourt S.L.
        • Martinez-Jimenez S.
        • Rossi S.E.
        • Truong M.T.
        • Carrillo J.
        • Erasmus J.J.
        Lipoid pneumonia: spectrum of clinical and radiologic manifestations.
        AJR Am J Roentgenol. 2010 Jan; 194: 103-109