Pseudoachalasia

Pseudoachalasia is achalatic typeachalasia-pattern dilatation of the oesophagus due to the narrowing of the distal oesophagus formfrom causes other than primary denervation such such as malignancy malignancy (often submucosal submucosal gastric cancer) with extension in the lower oesophagus³. 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; 6 months) unlike the chronic clinical history in patients with primary achalasia. Patients also tend to be older (>50Y;50 years) than those with primary achalasia.

Pathology

• oesophageal malignancy
  • gastric carcinoma (of the cardia and fundus)
  • oesophageal carcinoma
  • lymphoma
• central and peripheral neuropathy
  • brainstem stroke
  • brainstem infiltration: e, e.g. malignancy /, amyloidosis
  • infiltration of vagus by malignancy
  • complication of bilateral vagotomy
  • chronic idiopathic intestinal pseudoobstruction
  • diabetes mellitus
  • paraneoplastic 
• oesophageal stricture
  • ischaemia
  • reflux
  • acid / alkali/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 :

• obstruction of the lower oesophagus due to tumour proliferation
• tumour infiltration, denervation, or nerve malfunction of of the neuromeyntericneuromyenteric plexus of auerbach(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 discriminators in barium swallow, 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, lymph node involvement as well as regional and metastatic spread.