Peyer's patch morphology trait Peyer's patch epithelium morphology trait Antigen normally enters the Peyer's patch via this specialized epithelium. Any measurable or observable characteristic related to the shape, structure, color, or pattern of the specialized epithelium of the protruding lymphoid tissue located on the mucosa of the small intestine that is composed of densely packed B cell follicles. M cells morphology trait Trait.ontology VT:0002388