PERSISTENT DYSPHAGIA AND ESOPHAGEAL STASIS – THE ROLE OF IMAGING IN MEDIASTINAL CYSTIC LESIONS
8/28/2026 3:18:22 PM
A 37-year-old woman with no significant medical history presented with dysphagia, frequent acid reflux, and mild shortness of breath, particularly when lying down. Her symptoms had developed gradually and were not particularly severe, but had persisted for several years, significantly affecting her quality of life. She had previously undergone gastrointestinal endoscopy, which only revealed mild gastroesophageal reflux.
A frontal chest X-ray showed an abnormal opacity with widening of the upper mediastinum. The clinician subsequently ordered a neck ultrasound, which revealed a relatively large cystic lesion measuring approximately 6 - 7 cm, located beneath the skin in the anterior neck region and slightly left of the midline.
Given the presence of a well-defined cystic lesion extending from the neck into the chest, the patient was referred for a contrast-enhanced chest CT to provide detailed anatomical mapping and further characterize the lesion.
CONTRAST-ENHANCED CHEST CT FINDINGS
Chest CT provided a clear three-dimensional anatomical picture that explained the patient's persistent symptoms:
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Location and size: A cystic lesion was identified in the posterior mediastinum, just above the level of the aortic arch, extending from approximately C6 to T4. The lesion measured 60 × 38 × 70 mm (transverse × anteroposterior × craniocaudal).
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Morphological features: The cyst contained fluid with an attenuation of approximately 25 - 32 HU. Its wall was approximately 5 mm thick, with well-defined margins and no contrast enhancement following intravenous contrast administration.
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Mass effect: The cyst produced significant mass effect, displacing and compressing the trachea anteriorly while also causing marked compression and rightward displacement of the esophagus.
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Imaging impression: The findings were characteristic of a posterior mediastinal cyst, with an esophageal duplication cyst as the leading diagnostic consideration. Differential diagnoses included a bronchogenic cyst and a cystic degeneration of a neurogenic tumor.
CLINICAL INSIGHT
From both a clinical and pathological perspective, this case clearly demonstrates the close relationship between functional symptoms and imaging findings.
Explaining the Source of the Symptoms
The approximately 7 cm cyst caused significant mechanical compression of the esophagus, directly explaining the patient's dysphagia and symptoms of food stasis and regurgitation. These findings should be distinguished from uncomplicated functional gastroesophageal reflux disease.
Her shortness of breath when lying down was likely related to anterior displacement and compression of the trachea. Changes in body position may further alter the cyst's spatial relationship with the airway, increasing airway compression.
What Does the Cyst Fluid Attenuation Mean?
Simple fluid typically has a low attenuation of approximately 0 - 10 HU on CT. The higher attenuation of 25 - 32 HU suggests that the cyst contents may contain protein, mucus, or cellular debris, which is compatible with an enteric-type cyst lined by secretory mucosa.
Differential Diagnosis
The lesion's close proximity to the esophagus, direct compression, and tendency to share an intimate relationship with the esophageal wall are important features favoring an esophageal duplication cyst over a bronchogenic cyst.
However, for cystic lesions in the posterior mediastinum, neurogenic tumors should also be considered in the differential diagnosis.
THE VALUE OF CT AND IMAGING IN MEDIASTINAL EVALUATION
The mediastinum can be considered a “Pandora's box” of the chest, containing a wide range of anatomical structures and potential pathologies.
Although chest MRI may provide superior characterization of cyst contents, and endoscopic ultrasound (EUS) can offer detailed assessment of the esophageal wall layers, CT remains a key imaging modality in the evaluation of mediastinal lesions.
Overcoming Diagnostic Blind Spots
CT overcomes the limitations of conventional chest X-ray caused by anatomical overlap, as well as the limitations of conventional ultrasound due to the acoustic barriers created by the sternum and air-filled structures.
Surgical Mapping
CT provides accurate assessment of the cyst's spatial relationships with the trachea, esophagus, and aortic arch.
For esophageal duplication cysts, which may share a muscular wall with the esophagus, detailed CT imaging helps thoracic surgeons determine the most appropriate minimally invasive surgical approach, anticipate the risk of mucosal injury during dissection, and prepare for possible muscular-layer repair during surgery.
EXPERT MESSAGE: THE RIGHT IMAGING, THE RIGHT DIAGNOSIS
This case highlights several important lessons in clinical practice:
Don't Ignore Persistent Symptoms
Persistent gastrointestinal symptoms such as dysphagia and reflux, or respiratory symptoms such as shortness of breath when lying down, particularly when they do not respond adequately to conventional medical treatment, should prompt consideration of a mechanical compressive cause.
A Multimodality Diagnostic Approach Matters
The diagnostic process may begin with gastrointestinal endoscopy to exclude intraluminal lesions, complemented by basic imaging such as chest X-ray and neck ultrasound.
When an abnormality is identified, timely escalation to contrast-enhanced CT, with MRI and/or endoscopic ultrasound when appropriate, can help establish the diagnosis and support surgical planning.
Multidisciplinary Collaboration Is Key
Close collaboration among clinicians, radiologists, endoscopists, and surgeons—from initial clinical assessment and screening to advanced imaging and definitive treatment is essential for achieving an accurate diagnosis and optimal management of complex mediastinal lesions.