Pulmonary and Critical Care Pearls

Bilateral Alveolar Infiltrates in a 29-Year-Old Man with Chronic Myelogenous Leukemia

Physical Examination

The patient’s temperature was 38.5°C, BP was 130/80 mm Hg, pulse was 100 beats/min, and respiration was 40 breaths/min. The sclerae were not icteric. The pupils were isocoric with prompt light reflex. The neck was supple without jugular vein distension or lymphadenopathy. Chest auscultation revealed diffuse, coarse crackles bilaterally. There were no heart murmurs. The abdomen was soft and flat without tenderness or rigidity. The liver and spleen were not palpable. No skin rash or wounds were

Laboratory Findings

The initial laboratory studies revealed the following: WBC count, 26.8 × 10³ cells/μL with 94% neutrophils; platelet count, 778.0 × 10³ cells/μL; hemoglobin, 9.0 g/dL; and hematocrit, 28%. The prothrombin time and activated partial thromboplastin time were within normal limits. The aspartate aminotransferase level was 32 U/L, total bilirubin level was 0.9 mg/L, BUN level was 12 mg/L, creatinine level was 0.8 mg/L, and lactate dehydrogenase level was 965 U/L. The urinalysis showed no hematuria

Hospital Course

An open lung biopsy was performed on the 13th day of the hospital stay. The pathologic findings revealed confluent filling of alveolar spaces with eosinophilic, granular material positive for the periodic acid-Schiff staining which was resistant to diastase. No microorganisms or inflammatory cells could be identified.

What is most likely cause of the bilateral dense pulmonary infiltrates?

What is the most likely diagnosis?

Diagnosis: Secondary alveolar proteinosis complicating CML

Pulmonary alveolar proteinosis is a rare disease characterized by the deposition of a granular extracellular material composed of protein and lipids within the air spaces. Genetic predisposition, smoking, chemical exposure, and dust have been implicated in the pathogenesis of the disease, but the cause remains unknown. It has been hypothesized that alveolar proteinosis may be a consequence of defective macrophage function. The filling of proteinaceous material within the alveoli is thought to

Course and Treatment

IV cefotaxime and erythromycin were administered initially. Trimethoprim-sulfamethoxazole could not be used because of drug allergy. Profound hypoxemia, respiratory distress, and hypotension (ie, BP, 80/40 mm Hg) occurred 2 days later, and the patient was intubated and transferred to the ICUs.

The report of blood culture on the seventh day of hospitalization showed M abscessus. Antibiotics were therefore changed to imipenem, amikacin, and oral clarithromycin. Cultures of bone marrow and BAL

Clinical Pearls

• 1.

  Alveolar proteinosis should be considered in the differential diagnosis of patients with hematologic malignancies who present with chronic cough, exertional dyspnea, and diffuse alveolar lung infiltrates.

• 2.

  Secondary alveolar proteinosis is a possible cause of respiratory failure in patients with hematologic malignancies, especially in myeloid diseases.

• 3.

  The most common HRCT findings in patients with alveolar proteinosis are widespread ground-glass opacity and smooth septal thickening in abnormal