Ectopic feather follicles in a chicken teratoma or malformation

At necropsy of an 8-week-old pullet a 0.75 X 5.0 cm. yellowish, moderately firm cigar-shaped object was seen in the greater abdominal air sac lying parallel to the border of the right hepatic lobe. A capsule of 5 tissue layers (from inside outward-stratified squamous epithelium fibrous tissue, longitudinal muslce, fibrous tissue and circular muscle) enclosed featherlike structures which had developed from the stratified squamous epithelial layer. This combination of tissue components constituted ectopic follicles and feathers in a malformation or teratoma.