Achalasia. A morphologic study of 42 resected specimens

Area of Science:

• Gastroenterology and Esophageal Pathology
• Surgical Pathology and Disease Progression

Background:

• Achalasia is defined by impaired lower esophageal sphincter relaxation and absent esophageal peristalsis.
• Limited data exists on the histological progression and morphologic features of achalasia.
• Understanding these features is crucial for managing clinically unresponsive cases.

Purpose of the Study:

• To systematically identify morphologic features in esophagi from patients with achalasia.
• To determine the histological progression of achalasia, particularly in surgically resected specimens.
• To correlate histological findings with clinical presentation of unresponsive achalasia.

Main Methods:

• Histological examination of esophagi from 42 patients who underwent total thoracic esophagectomy for achalasia.
• Systematic assessment of myenteric ganglion cells, nerve inflammation, and associated esophageal tissue changes.
• Evaluation of extramyenteric features including muscular hypertrophy, squamous changes, and inflammation.

Main Results:

• Marked depletion of myenteric ganglion cells in the esophageal body, with complete absence in 20 cases.
• Widespread inflammation within myenteric nerves (lymphocytes, eosinophils) and focal to near-complete replacement by collagen.
• Extramyenteric changes included muscular hypertrophy, squamous hyperplasia, and chronic inflammation, with some cases showing dysplasia and squamous cell carcinoma.

Conclusions:

• Clinically unresponsive achalasia involves near-total loss of ganglion cells and extensive myenteric nerve destruction.
• Myenteric inflammation is a prominent feature, but its role as a cause or consequence of nerve destruction is unclear.
• Chronic stasis and prior surgical interventions contribute significantly to the observed esophageal pathology.