Figure 6 - Histopathology of achalasia.

a: Normal myenteric plexus demonstrating multiple ganglion cells and minimal lymphocytic infiltration. b: Mild myenteric inflammation. There is mild lymphocytic inflammation, and ganglion cells can be identified. c: Moderate myenteric inflammation with lymphocytic infiltrate is present. Ganglion cells are absent. d: Severe myenteric inflammation with lymphocytes densely clustered within this myenteric plexus. Ganglion cells are absent. (Source: Hirano and Kahrilas¹¹² with permission from Blackwell Publishing.)