Pulmonary caseating granulomas associated with Mycoplasma pneumoniae pneumonia.

Severe Mycoplasma pneumoniae pneumonia, complicated by autoimmune hemolytic anemia, monarticular arthritis, and persistent upper lobe consolidation, clinically simulating pulmonary tuberculosis, occurred in a young girl. A specimen taken at open lung biopsy grew Mycoplasma pneumoniae and microscopically showed caseating granulomas, a finding never previously associated with M pneumoniae infection. Although it is possible that another infectious or immunologic granulomatous lung disease may have been responsible for the unusual clinical, roentgenographic, and pathologic findings, no other etiologic agent was identified.