
Aggregated lymphoid nodules: Peyer's patch
This Peyer’s patch demonstrates the accumulation of lymphoid tissues in the ileum. Although secondary nodules are usually characteristic of Peyer’s patches, none are seen here. However, primary nodules and diffuse lymphoid tissue are prevalent. Because Peyer’s patches are located in the lamina propria of the mucosa, they are part of MALT and filter tissue fluid. 200x

Peyer's patch
This Peyer’s patch demonstrates the accumulation of lymphoid tissues in the ileum. Although secondary nodules are usually characteristic of Peyer’s patches, none are seen here. However, primary nodules and diffuse lymphoid tissue are prevalent. Because Peyer’s patches are located in the lamina propria of the mucosa, they are part of MALT and filter tissue fluid. 200x

Primary nodule
This Peyer’s patch demonstrates the accumulation of lymphoid tissues in the ileum. Although secondary nodules are usually characteristic of Peyer’s patches, none are seen here. However, primary nodules and diffuse lymphoid tissue are prevalent. Because Peyer’s patches are located in the lamina propria of the mucosa, they are part of MALT and filter tissue fluid. 200x

Diffuse lymphoid tissue
This Peyer’s patch demonstrates the accumulation of lymphoid tissues in the ileum. Although secondary nodules are usually characteristic of Peyer’s patches, none are seen here. However, primary nodules and diffuse lymphoid tissue are prevalent. Because Peyer’s patches are located in the lamina propria of the mucosa, they are part of MALT and filter tissue fluid. 200x

Lumen of ileum
This Peyer’s patch demonstrates the accumulation of lymphoid tissues in the ileum. Although secondary nodules are usually characteristic of Peyer’s patches, none are seen here. However, primary nodules and diffuse lymphoid tissue are prevalent. Because Peyer’s patches are located in the lamina propria of the mucosa, they are part of MALT and filter tissue fluid. 200x

Mucosa
This Peyer’s patch demonstrates the accumulation of lymphoid tissues in the ileum. Although secondary nodules are usually characteristic of Peyer’s patches, none are seen here. However, primary nodules and diffuse lymphoid tissue are prevalent. Because Peyer’s patches are located in the lamina propria of the mucosa, they are part of MALT and filter tissue fluid. 200x

Submucosa
This Peyer’s patch demonstrates the accumulation of lymphoid tissues in the ileum. Although secondary nodules are usually characteristic of Peyer’s patches, none are seen here. However, primary nodules and diffuse lymphoid tissue are prevalent. Because Peyer’s patches are located in the lamina propria of the mucosa, they are part of MALT and filter tissue fluid. 200x

Muscularis externa
This Peyer’s patch demonstrates the accumulation of lymphoid tissues in the ileum. Although secondary nodules are usually characteristic of Peyer’s patches, none are seen here. However, primary nodules and diffuse lymphoid tissue are prevalent. Because Peyer’s patches are located in the lamina propria of the mucosa, they are part of MALT and filter tissue fluid. 200x