IPLab:Lab 9:Diphtheria

Clinical Summary

This 4-year-old black female had an upper respiratory infection and a sore throat with increasing difficulty in breathing. Membranous exudate over one tonsil led to a working diagnosis of diphtheria, and the child was admitted. On the day of her admission, the child developed signs of respiratory tract obstruction and a tracheotomy was performed. However, the procedure was unable to establish a patent airway and the child died.

Autopsy Findings

At autopsy, a dense grayish pink membrane extended from both tonsils to the mid-trachea. The lungs were edematous and showed signs of pneumonia.

Images

• 
  This is a low-power photomicrograph of the trachea with the diphtheritic membrane (1), which has pulled away from the tracheal lining during histological processing. Note the tracheal cartilage (2) present in this section.
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  This is a higher-power photomicrograph of trachea with the diphtheritic membrane (1). Even though, the main part of the membrane has pulled away from the tracheal lining during histological processing, in this section part of the membrane is still loosely attached. Once again, note the tracheal cartilage (2).
• 
  This is an even higher-power photomicrograph of the tracheal mucosa and the diphtheritic membrane. The mucosal surface of the trachea is ulcerated (total loss of epithelial cells) and the only remaining epithelial cells are found in the glands (arrows). The diphtheritic membrane consists of fibrin and inflammatory cells, most of which are dead.
• 
  In this higher-power photomicrograph of the tissue from the previous image, the ulcerated tracheal mucosa and the diphtheritic membrane are more clearly seen. Although difficult to make out at this magnification, most of the cells in this inflammatory exudate are neutrophils.

In alcoholics, aspiration pneumonia is common--bacteria enter the lung via aspiration of gastric contents.