Utility of chest CT for differentiating primary and secondary achalasia

Aim: To determine the computed tomography (CT) findings of primary and secondary achalasia and to assess the utility of CT for differentiating these conditions.

Methods: A computerized search revealed 13 patients with primary achalasia and 15 with secondary achalasia who underwent chest CT during a 10-year period. The images were reviewed to determine whether there was distal oesophageal narrowing (including the length/contour of narrowing), oesophageal dilation, oesophageal wall thickening (including degree/symmetry/pattern of thickening), a soft-tissue mass at the gastro-oesophageal junction, mediastinal adenopathy, or other findings of malignant tumour.

Results: Eleven (85%) of 13 patients with primary achalasia had distal oesophageal narrowing at CT that was smooth in all patients; four (31%) had oesophageal wall thickening that was smooth and symmetric in all patients; none had a soft-tissue mass at the gastro-oesophageal junction or mediastinal lymphadenopathy; and two (15%) had pulmonary metastases from unrelated lung cancers. In contrast, 12 (80%) of 15 patients with secondary achalasia had distal oesophageal narrowing at CT; 11 (73%) had distal oesophageal wall thickening that was nodular/lobulate and asymmetric in seven (64%) and smooth and symmetric in four (36%); six (40%) had a soft-tissue mass at the gastro-oesophageal junction; seven (47%) had mediastinal lymphadenopathy; and all 15 had other findings of malignant tumour.

Conclusion: CT is a useful technique for differentiating primary and secondary achalasia. Distal oesophageal wall thickening that is nodular/lobulate and asymmetric, a soft-tissue mass at the gastro-oesophageal junction, mediastinal lymphadenopathy, and pulmonary, hepatic, or osseous metastases are findings that favour secondary achalasia.