Shope fibroma: electron microscopic structure of associated lamellae

The striated lamellae associated with Shope fibroma virus infection are made up of disk-shaped units ∼ 10 nm in diameter and ∼ 4 nm thick. Unstriated lamellae are made up of oval units varying in size and not clearly resolved but of the order of 7 nm in diameter. The lamellae on cross section are separated from one another by a space containing an irregular dense line. Similar lamellae have been seen in fowl pox of turkey origin, swine pox, ectromelia, rabbit myxoma, and canary pox.