Herpes Simplex Virus Pneumonia: Importance of Aspiration Etiology

Figure 1

HSV infection in the upper (top panels) and lower (bottom panels) airway. Left: gross appearance after formalin fixation, center: hematoxylin and eosin staining, right: immunostaining for HSV-1 (amino acid polymer method with HSV-1 antiserum). The epiglottis reveals a hemorrhagic ulcer (yellow arrow), while hemorrhagic erosions are distributed on the pharyngeal and tracheal mucosa (red arrowheads). The vesicular mucosal lesion in the pharynx consists of acantholytic squamous cells with intranuclear inclusions and evident immunoreactivity of HSV-1 antigen. The lower lobe of the lung reveals parenchymal infiltration (blue arrowheads), surrounded by subpleural cyst-forming fibrosis. Microscopically, the bronchiolar (green arrows) and parenchymal alveolar cells show intranuclear inclusions with strong HSV-1 immunoreactivity.