Question
A 61-year-old woman presents to the emergency department with fever and a productive cough. She has otherwise been healthy but reports a 3-month history of difficulty swallowing both liquids and solids. A chest X-ray reveals a fluid level located behind the cardiac shadow. What is the most likely diagnosis?
a) Large pericardial effusion
b) Pulmonary tuberculosis
c) Achalasia
d) Zenker’s diverticulum
e) Sliding hiatal hernia
Answer
Achalasia
Detailed Explanation
This is a classic MRCP-style integration question combining dysphagia pattern + radiology clue.
Key Clinical Clues
- Dysphagia to BOTH solids and liquids from the beginning
→ Suggests motility disorder, not mechanical obstruction - Chronic duration (months)
- Cough + fever
→ Likely aspiration due to regurgitation - Chest X-ray: retrocardiac air-fluid level
→ Indicates dilated oesophagus with retained food/fluid
Pathophysiology
- Degeneration of Auerbach’s (myenteric) plexus
- Leads to:
- Failure of lower oesophageal sphincter (LOS) relaxation
- Loss of peristalsis
- Result:
- Functional obstruction → proximal oesophageal dilatation
Why Achalasia fits perfectly
- Dysphagia to liquids + solids → hallmark
- Air-fluid level behind heart → dilated oesophagus
- Aspiration → explains cough + fever
Why other options are wrong
- Large pericardial effusion
→ Enlarged cardiac silhouette, not air-fluid level - Tuberculosis
→ Parenchymal changes, cavities, lymphadenopathy - Zenker’s diverticulum (pharyngeal pouch)
→ Dysphagia + regurgitation, but neck swelling, halitosis, not retrocardiac shadow - Hiatal hernia
→ May show air-fluid level, but dysphagia to both liquids early is uncommon
Cheat Sheet (Exam Gold)
- Dysphagia pattern:
- Liquids + solids from start → motility disorder
- Solids → liquids → mechanical obstruction
- Achalasia:
- Cause → myenteric plexus degeneration
- LOS → fails to relax
- Oesophagus → dilated
- X-ray:
- Retrocardiac air-fluid level
- Wide mediastinum
- Barium swallow:
- Bird’s beak appearance
- Gold standard:
- Oesophageal manometry
Flash Cards
Q1: Dysphagia to liquids and solids suggests what?
A: Motility disorder (e.g., achalasia)
Explanation: Mechanical obstruction starts with solids first
Q2: What plexus is damaged in achalasia?
A: Auerbach’s (myenteric) plexus
Explanation: Controls oesophageal motility and LOS relaxation
Q3: Classic barium swallow finding in achalasia?
A: Bird’s beak appearance
Explanation: Tapering at distal oesophagus
Q4: Gold standard investigation for achalasia?
A: Oesophageal manometry
Explanation: Shows high LOS tone and failure to relax
Q5: Why do patients develop cough in achalasia?
A: Aspiration of retained food
Explanation: Due to oesophageal stasis
MCQs (High Difficulty)
MCQ 1
A 52-year-old man has progressive dysphagia to both liquids and solids. Which mechanism best explains this condition?
a) Increased gastric acid secretion
b) Loss of inhibitory neurons in oesophagus
c) External compression by mediastinal mass
d) Fibrosis of oesophageal mucosa
Answer: b
Explanation: Achalasia involves loss of inhibitory neurons (NO/VIP), causing failure of LOS relaxation
MCQ 2
Which radiological feature is most characteristic of achalasia?
a) Double bubble sign
b) Bird’s beak tapering
c) Thumbprinting
d) String sign
Answer: b
Explanation: Classic distal oesophageal tapering
MCQ 3
Which of the following is FALSE regarding achalasia?
a) Dysphagia is worse for liquids initially
b) LOS fails to relax
c) Risk of oesophageal carcinoma is increased
d) It is caused by increased vagal tone
Answer: d
Explanation: It is due to degeneration of myenteric plexus, not increased vagal tone
MCQ 4
A chest X-ray showing retrocardiac air-fluid level suggests:
a) Pleural effusion
b) Dilated oesophagus
c) Left atrial enlargement
d) Pericardial tamponade
Answer: b
Explanation: Seen in achalasia due to retained food/fluid
MCQ 5
Best initial treatment for symptomatic achalasia in a fit patient:
a) Proton pump inhibitors
b) Pneumatic balloon dilatation
c) Antibiotics
d) Steroids
Answer: b
Explanation: First-line in most cases
MCQ 6
Which symptom best differentiates achalasia from oesophageal cancer?
a) Weight loss
b) Dysphagia to liquids from onset
c) Chest pain
d) Regurgitation
Answer: b
Explanation: Cancer → solids first; achalasia → both from start
Summary for Quick Exam Revision
Achalasia is a motility disorder caused by degeneration of the myenteric plexus leading to failure of lower oesophageal sphincter relaxation and absence of peristalsis. It typically presents with dysphagia to both liquids and solids from the onset, distinguishing it from mechanical obstruction. Patients often develop regurgitation and aspiration, leading to cough or pneumonia. Imaging may show a retrocardiac air-fluid level on chest X-ray and a dilated oesophagus. Barium swallow demonstrates the classic bird’s beak appearance, while oesophageal manometry is the gold standard diagnostic test showing high LES tone and incomplete relaxation. First-line treatment is pneumatic dilatation, with surgical myotomy reserved for refractory cases. There is also a small increased risk of oesophageal carcinoma in long-standing disease.