What is a common histologic finding in cytomegalovirus pneumonia?

• A. Giant cell formation
• B. Basophilic nuclear inclusions
• C. Granulomatous inflammation
• D. Fibrosis

Answer: (B)

Cytomegalovirus (CMV) pneumonia is characterized by the presence of specific histologic findings, with basophilic nuclear inclusions being a hallmark feature. These inclusions are a result of the viral replication process within the cells and are indicative of CMV infection. The cells infected with CMV typically show enlarged nuclei filled with intranuclear inclusions that often stain basophilic due to the viral particles. This finding is significant in diagnosing CMV-related diseases, particularly in immunocompromised patients, where the virus can cause severe pulmonary complications.

Giant cell formation may be observed in some viral infections, but it is not as specific to CMV as basophilic nuclear inclusions. Granulomatous inflammation is seen in other types of lung infections, such as tuberculosis or certain fungal infections, and fibrosis may occur as a sequela of chronic lung disease but is not a defining feature of CMV pneumonia. Thus, the presence of basophilic nuclear inclusions is the most relevant and distinctive histologic finding in CMV pneumonia.