What is the histologic pattern of viral myocarditis and which virus is most classically associated?

What is the histologic pattern of viral myocarditis and which virus is most classically associated?

• A. Granulomatous inflammation; Coxsackie A virus
• B. Lymphocytic infiltrate with myocyte necrosis; Coxsackie B virus is classically associated
• C. Neutrophilic infiltration; Adenovirus
• D. Eosinophilic infiltrate; Parvovirus B19

Answer: (B)

Viral myocarditis classically shows an interstitial lymphocytic infiltrate with myocyte necrosis, reflecting a cell-mediated immune response targeting infected heart muscle. Among viruses, Coxsackie B virus is the quintessential association; it’s a nonenveloped RNA picornavirus classically linked to this pattern in teaching and textbooks. While other viruses like adenovirus or Parvovirus B19 can also cause myocarditis, they are not as strongly or traditionally associated. The other histologic patterns—neutrophilic infiltration (more typical of bacterial infection), granulomatous inflammation (seen with TB or sarcoidosis), or eosinophilic infiltrate (seen in hypersensitivity or parasitic contexts)—do not match the classic viral myocarditis picture.

Viral myocarditis classically shows an interstitial lymphocytic infiltrate with myocyte necrosis, reflecting a cell-mediated immune response targeting infected heart muscle. Among viruses, Coxsackie B virus is the quintessential association; it’s a nonenveloped RNA picornavirus classically linked to this pattern in teaching and textbooks. While other viruses like adenovirus or Parvovirus B19 can also cause myocarditis, they are not as strongly or traditionally associated. The other histologic patterns—neutrophilic infiltration (more typical of bacterial infection), granulomatous inflammation (seen with TB or sarcoidosis), or eosinophilic infiltrate (seen in hypersensitivity or parasitic contexts)—do not match the classic viral myocarditis picture.