A 6-year-old boy presents with painful sores on his upper lip. He was seen for a flu 1 week ago. The lesion appears as 0.2- to 0.4-cm vesicles with focal ulceration. Which of the following is the most likely histologic feature of this skin lesion?
Acute arteritis Caseating granulomas Fungal hyphae Multinucleated epithelial cells