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Pulmonary infiltrate with characteristic “reversed halo” and “air crescent” signs

  • Claudia Imburgia
    Correspondence
    Corresponding author.
    Affiliations
    2nd Internal Medicine Department and Infectious Disease Unit, National Relevance Hospital Trust, ARNAS Civico, Di Cristina e Benfratelli, Palermo, Italy
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  • Calogero Buscemi
    Affiliations
    2nd Internal Medicine Department and Infectious Disease Unit, National Relevance Hospital Trust, ARNAS Civico, Di Cristina e Benfratelli, Palermo, Italy
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  • Salvatore Corrao
    Affiliations
    2nd Internal Medicine Department and Infectious Disease Unit, National Relevance Hospital Trust, ARNAS Civico, Di Cristina e Benfratelli, Palermo, Italy

    Centre of Research for Effectiveness and Appropriateness in Medicine (CREAM), Biomedical Department of Internal Medicine and Subspecialties [DiBiMIS], University of Palermo, Italy
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Published:December 12, 2016DOI:https://doi.org/10.1016/j.ejim.2016.12.005

      1. Case description

      A brain mass had been diagnosed to a 62 years old man after an epileptic fit and subsequent comatose status. The mass had been excised; it was an anaplastic astrocytoma. After chemotherapy and radiotherapy cycles, he arrived at the emergency department of our hospital suffering from fever and ingravescent dyspnea. On admission his body temperature was 37.5 °C, blood pressure and heart rate were normal and respiratory rate was 35 breaths per minute. Laboratory exam underlined pancytopenia and elevated C-reactive protein (CRP 19.7 mg/L; norm: <0.3). The computed tomography (CT) (Fig. 1a ) showed a pulmonary ground-glass nodule surrounded by a dense ring into the superior lobe of the left lung. Bronchoscopy was performed and the biopsy of the nodule was done. After three months a second CT was done, showing interval development of cavitation (Fig. 1b).
      Fig. 1
      Fig. 1a Computed tomography of the thorax (pulmonary window) shows a ground-glass opacity, in the left superior lobe, surrounded by a ring along the circumference of the nodule. This sign is known as the “reversed halo” sign.
      b Computed tomography scan performed three-month later shows interval development of cavitation named as the “air crescent” sign.

      2. What's diagnosis?

      2.1 Diagnosis

      Invasive aspergillosis is one of the most important causes of morbidity and mortality in immunocompromised patients. It is a fungal infection caused by inhalation of the Aspergillus spores. The species associated with invasive infection are Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus and Aspergillus niger that are able to cause lung infection, preferentially.
      The clinical spectrum of pulmonary aspergillosis is diverse and it is divided into three main categories: invasive pulmonary aspergillosis, aspergilloma, allergic bronchopulmonary aspergillosis.
      In our case, diagnosis of invasive aspergillosis was confirmed by histological exam of nodule. Voriconazole 6 mg/Kg bid (loading dose for two administrations) and then 4 mg/kg bid was started and patient clinically improved. After three months, CT of the lung was repeated.
      The first CT (Fig.1a) shows a ground-glass opacity surrounded by a dense ring, known as “reversed halo” sign [
      • Godoy M.C.B.
      • Viswanathan C.
      • Marchiori E.
      • et al.
      The reversed halo sign: update and differential diagnosis.
      ]. The second CT (Fig. 1b) shows interval development of cavitation. This sign is known as “air crescent” sign [
      • Abramson S.
      The air crescent sign.
      ] that is related to almost partial healing of infection.
      This sign must not be confused with the monad sign that represents the mycotic colonization of a cavity in the lung.

      References

        • Godoy M.C.B.
        • Viswanathan C.
        • Marchiori E.
        • et al.
        The reversed halo sign: update and differential diagnosis.
        Br J Radiol. 2012; 85: 1226-1235
        • Abramson S.
        The air crescent sign.
        Radiology. Jan 2001; 218: 230-232