IPLab:Lab 10:Blastomycosis

Clinical Summary

About three weeks before his death, this 17-year-old white male developed a "chest cold" which gradually worsened. The patient was eventually admitted three days before his death. At that time, the patient was very dyspneic. Chest x-ray showed consolidation of the entire left lung. The initial impression by his care team was staphylococcal pneumonia. However, Blastomyces dermatitides was identified in stained smears of sputum the next day. In spite of appropriate antifungal therapy, the patient deteriorated rapidly and died.

Autopsy Findings

Autopsy confirmed that the entire left lung was semi-solid.

Images

• 

  This gross photograph of the lungs shows areas of necrosis and consolidation.

• 

  This higher-power view of the lung shows more clearly the areas of necrosis (1) and consolidation (2). Satellite lesions are also present (3).

• 

  This is a low-power photomicrograph of lung showing many areas of consolidation (arrows).

• 

  This is a high-power photomicrograph of lung section with pleura. The pleura (1) is thickened and contains inflammatory cells and fibrin. The areas of consolidation (2) are dense and filled with inflammatory cells.

• 

  This is a higher-power photomicrograph of lung section with pleura. The pleura (arrows) is thickened and contains inflammatory cells and fibrin. The alveoli are filled with inflammatory cells. Some of the alveolar septa are congested with red blood cells.

• 

  This high-power photomicrograph shows what appear to be inflammatory cells filling the alveoli. At this magnification, numerous round bodies (arrows) that look like inflammatory cell nuclei can be seen. However, on closer examination, some of these round bodies are surrounded by clear halos.

• 

  This high-power photomicrograph shows an alveolus filled with numerous round bodies up to 25 mm in diameter. Some of these double-contour bodies (1) have a dense center and a clear halo. These are the Blastomyces organisms. The typical B. dermatitides organism is smoothly-outlined with a central, densely basophilic cytoplasm surrounded by a clear halo. When stained with hematoxylin and eosin, the organism is outlined by a relatively thick cell wall. There are also numerous inflammatory cells (2) in the alveolus--neutrophils, lymphocytes and macrophages--which produce a pyogranulomatous inflammatory reaction.

• 

  This is a high-power photomicrograph showing an alveolus filled with Blastomyces organisms. This section is stained with Periodic Acid-Schiff (PAS) to stain the Blastomyces organisms.

• 

  This high-power photomicrograph shows Blastomyces organisms stained with PAS. Note the budding organism (arrow). Blastomyces has a characteristic presentation of budding which aids in diagnosis of the fungus.

• 

  This is a very high-power photomicrograph showing Blastomyces organisms stained with PAS. Note the budding organism (arrow) and the underlying pyogranulomatous inflammatory reaction in the background.