General Surgery – Mediastinal Mass: By Rishindra M. Reddy M.D.

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07/18/23

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General Surgery – Mediastinal Mass
Whiteboard Animation Transcript
with Rishindra M. Reddy, MD
https://medskl.com/module/index/mediastinal-mass

The mediastinum is an anatomical cavity, which is in between the lungs, and includes the heart, aorta, thymus, trachea and esophagus. Its boundaries are formed by the sternum anteriorly, the spine posteriorly and the lungs laterally. Further, the mediastinum can be subdivided into three anatomical areas, specifically the anterior, middle, and posterior mediastinum. These distinctions are important, as the location of a mass can hint to its etiology.

Masses in the anterior mediastinum can include:

–Lymphoma (Hodgkin’s and non-Hodgkin’s)
–Thymoma and thymic cysts
–Germ cell tumours
–Retrosternal goiters (Thyroid masses)

Masses in the middle mediastinum can include:

–Lymphadenopathy (enlarged lymph nodes)
–Tracheal tumours
–Bronchogenic cysts/tumors
–Pericardial cysts

Masses in the posterior mediastinum can include:

–Esophageal tumors
–Esophageal diverticula
–Paraesophageal hiatal hernias
–Lymphadenopathy
–Nerve sheath tumours

Diagnosis of mediastinal masses is difficult, because many patients will be asymptomatic until the mass begins to encroach on surrounding structures. As such, large anterior masses may cause dyspnea when the patient lies supine. Similarly, posterior masses may cause dysphagia or odynophagia by compressing the esophagus.

Lymphomas will typically present with “B” symptoms, and may be diagnosed earlier if the following are present:

1. Night time sweating
2. Fever greater than 38ºC
3. Unexplained weight loss

Most commonly however, a mediastinal mass will be discovered incidentally on chest x-ray. Further investigation may involve a CT/MRI scan, followed by a tissue biopsy, if indicated, which can be performed by endoscopy, thorocoscopy, external needle biopsy, etc.

Treatment typically depends on the type of tumour. Thymic cancers may be treated by surgical resection and possibly radiation. Lymphomas are treated with chemotherapy followed by radiation.