Pseudoachalasia

Pseudoachalasia is aachalatic type dilatation of oesphageal motility disorder which is associated with malignancythe oesophagus due to the narrowing of the distal oesophagus form causes other than primary denervation such as malignancy (often submucosal gastric cancer) with extension in the lower oesophagus ³. The clinical and imaging similarities of achalasia and pseudoachalasia pose a differential dilemma, usually requiring further investigation.

Clinical presentation

The clinical course of pseudoachalasia depends on the underlying cause however it, in particular if secondary to the neoplasm, is usually short short (<6 months) unlike the chronic clinical history in patients with primary achalasia. Patients also tend to be older (>50Y) than those with primary achalasia.

Pathology

The most common cancer type is adenocarcinomaCauses of the fundus andpseudoachalasia include: 

• oesophageal malignancy
  • gastric carcinoma (of the cardia of the stomach. Less common tumour types include and fundus)
  • oesophageal carcinoma
  • lymphoma
• central and carcinomaperipheral neuropathy
  • brainstem stroke
  • brainstem infiltration: e.g. malignancy / amyloidosis
  • infiltration of the pancreas or lungs.vagus by malignancy
  • complication of bilateral vagotomy
  • chronic idiopathic intestinal pseudoobstruction
  • diabetes mellitus
  • paraneoplastic
• oesophageal stricture
  • ischaemia
  • reflux
  • acid / alkali ingestion
• scleroderma
  • may have oesophageal dilatation but with an open incompetent lower oesophageal sphincter, and thus no stasis is present - thus not really achalasia pattern

The pathophysiology of pseudoachalasia is thought to be twofold :

1. obstruction of the lower oesophagus due to tumortumour proliferation
2. tumour infiltration of, denervation, or nerve malfunction of the neuromeynteric plexus of auerbach thus creating functional obstruction similar to achalasia

Although less common, it is possible for primary achalasia and malignancy to coexist.

Radiographic features

The plain chest film and barium swallow findings are similar to achalasia and may also show other features of the underlying cause (listed above).

Two useful discriminators in barium swallow are, particularly in cases secondary to underlying neoplasm, are:

• the mucosal irregularity of malignant lesions in pseudoachalasia
• the temporary patency of lower oesophageal sphincter if the hydrostatic pressure is increased in achalasia

Computed tomography is usually the imaging modality of choice for equivocal cases because it depicts the malignant lesion, lymphnodelymph node involvement as well as regional and metastatic spread.