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“Milking” the way to diagnosis

Published:August 11, 2022DOI:https://doi.org/10.1016/j.ejim.2022.08.007

      1. Case description

      A 43-year-old non-smoker man presented to the emergency department with exertional dyspnoea and left pleuritic pain lasting for 3 days. He denied fever and cough and described a history of pulmonary embolism, deep venous thrombosis and multiple opportunistic infections, namely angio-invasive pulmonary aspergillosis and pulmonary and brain Nocardia sp. Infections, the brain abscess requiring surgical excision and causing squeal epilepsy. He was chronically medicated with rivaroxaban 20 mg id, Levetiracetam 500 mg bid and co-trimoxazole 960 mg bid 3 times a week.
      On physical examination, the patient presented signs of respiratory failure with blood oxygen saturation of 94% using a 31% venturi mask, and bilateral basal crackles on lung auscultation. He showed no indication of peripheral oedema or deep venous thrombosis, and his inflammatory parameters were within the normal range. A high-resolution chest computed tomography exhibited diffuse ground-glass opacities with interlobular and intralobular septal thickening, a pattern described as crazy paving (Panel A), and a subsequent bronchoscopy yielded a milky appearing lavage fluid (Panel B) composed of periodic acid–Schiff (PAS) positive proteinaceous material (Fig. 1).
      What is the diagnosis?
      Diagnosis: Pulmonary alveolar proteinosis

      2. Discussion

      Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease caused by impaired surfactant turnover. Its aetiology can be autoimmune, congenital or secondary, the first accounting for 90% of the documented cases [
      • Borie R.
      • Danel C.
      • Debray M.-P.
      • Taille C.
      • et al.
      Pulmonary alveolar proteinosis.
      ,
      • Carrington JM
      • Hershberger D.M.
      Pulmonary Alveolar Proteinosis.
      ].
      Symptoms of PAP are unspecific and almost one-third of the patients are asymptomatic [
      • Borie R.
      • Danel C.
      • Debray M.-P.
      • Taille C.
      • et al.
      Pulmonary alveolar proteinosis.
      ]. Dyspnoea is the most common symptom at presentation, initially present only on exertion, and then slowly increasing for lesser efforts. Cough is also frequent and can be either productive or dry. Other symptoms include tachypnea, global respiratory failure, and, less frequently, fever, weight loss, fatigue and chest pain [
      • Borie R.
      • Danel C.
      • Debray M.-P.
      • Taille C.
      • et al.
      Pulmonary alveolar proteinosis.
      ,
      • Carrington JM
      • Hershberger D.M.
      Pulmonary Alveolar Proteinosis.
      ]. A combination of appropriate serological, radiological and bronchoscopic studies is often needed for the diagnosis, but the gold standard is the bronchoscopy with bronchoalveolar lavage [
      • Carrington JM
      • Hershberger D.M.
      Pulmonary Alveolar Proteinosis.
      ].
      Although the crazy paving pattern is often associated with PAP [
      • Borie R.
      • Danel C.
      • Debray M.-P.
      • Taille C.
      • et al.
      Pulmonary alveolar proteinosis.
      ], it is not specific for this pathology and can be observed in many other conditions, e.g., cardiogenic pulmonary oedema, acute respiratory distress syndrome and infections by Mycoplasma and Pneumocystis jirovecii pneumonia [

      Radiopedia.org. 2020. Crazy Paving | Radiology Reference Article | Radiopedia.org | [online]. Available at: http://radiopedia.org/articles/crazy-paving [Accessed 3 June 2020].

      ]. Moreover, patients with PAP are at increased risk of developing opportunistic infections, being the lung the most commonly affected organ. Nocardia sp. and Mycobacterium tuberculosis are the two most commonly reported opportunistic infections [
      • Carrington JM
      • Hershberger D.M.
      Pulmonary Alveolar Proteinosis.
      ].
      In conclusion, PAP is a rare disease that is difficult to diagnose and treat. Due to its unpredictable prognosis, a multidisciplinary team composed of both trained clinicians and nurses is often required to successfully provide the best care for these patients and improve their outcome [
      • Carrington JM
      • Hershberger D.M.
      Pulmonary Alveolar Proteinosis.
      ].

      References

        • Borie R.
        • Danel C.
        • Debray M.-P.
        • Taille C.
        • et al.
        Pulmonary alveolar proteinosis.
        Eur Respir Rev. 2011; 20: 98-107https://doi.org/10.1183/09059180.00001311
        • Carrington JM
        • Hershberger D.M.
        Pulmonary Alveolar Proteinosis.
        (StatPearls [Internet])Treasure Island. StatPearls Publishing, FL2022 (Jan-. Available from)
      1. Radiopedia.org. 2020. Crazy Paving | Radiology Reference Article | Radiopedia.org | [online]. Available at: http://radiopedia.org/articles/crazy-paving [Accessed 3 June 2020].