How to distinguish between primary achalasia and secondary achalasia based on clinical and cross sectional imaging features?
Primary achalasia typically presents clinically with long-standing slowly progressive dysphagia usually in adult patients <50 to 60 years of age. On cross-sectional imaging, smooth tapered narrowing of the distal esophagus is seen, sometimes with mild smooth wall thickening, in association with upstream esophageal dilation, which can be massive and associated with retained ingested debris. No soft tissue mass at the gastroesophageal junction, regional lymphadenopathy, or distant metastases are seen.
Secondary achalasia typically presents clinically with a more acute onset and a more rapid progression of symptoms (usually within 6 months) in older patients (usually >60 years of age). On cross-sectional imaging, upstream esophageal dilation is again seen, but additional suggestive imaging features may be present including distal esophageal wall thickening that is nodular, lobulated, or asymmetric; a soft tissue mass at the gastroesophageal junction; regional lymphadenopathy or distant metastatic disease. Adenocarcinoma of the gastric cardia, gastric fundus, or distal esophagus is the most frequent tumor that causes secondary achalasia.
