Clinical and Interpretive

The observation of particular cellular patterns in a Bronchoalveolar Lavage (BAL) sample can provide useful diagnostic information to providers concerning various thoracic conditions. Inflammatory cellular patterns in a BAL differential can be noted by an increased amount of lymphocytes, eosinophils, or neutrophils.�� These patterns, though nonspecific, can assist clinicians in the differential diagnosis of ILDs and other conditions.�� It should be noted that normal BAL differentials results do��not exclude abnormalities in the lung tissue.

Normal cellular populations in BAL:

• 0-30% lymphoctyes
• 0-10% neutrophils
• 0-1% eosinophils

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