SU26.3 | Mediastinal Diseases — Summary & Reflection

KEY TAKEAWAYS

Mediastinal disease presents in three ways: incidental (widened mediastinum on imaging), compressive (cough/stridor, dysphagia, hoarseness, superior vena cava obstruction), and systemic/syndromic (myasthenia gravis with thymoma, B symptoms with lymphoma). The organising principle is that the compartment predicts the pathology. The anterior mediastinum holds the four T's — Thymoma (± myasthenia gravis), Teratoma/germ-cell tumour, retrosternal Thyroid, and 'Terrible' lymphoma. The middle mediastinum holds lymphadenopathy (lymphoma, metastatic, TB/sarcoid) and benign cysts (bronchogenic, pericardial). The posterior mediastinum holds neurogenic tumours. Work-up runs chest X-ray → contrast CT thorax (localise, characterise) → tumour markers (AFP, beta-hCG) and tissue biopsy where treatment is non-surgical. Management is diagnosis-driven: resect localised/benign or curable masses (thymectomy, retrosternal thyroid, teratoma, cysts, neurogenic tumours), but lymphoma is treated by chemotherapy and radiotherapy, not surgery. Superior vena cava obstruction demands urgent treatment of the cause, with stenting for rapid relief.

REFLECT

Think of a chest X-ray you have reviewed, or imagine being handed one that shows a widened mediastinum. Could you decide which compartment a mass most likely occupies, and recall what that compartment characteristically contains — the four T's anteriorly, lymphadenopathy and cysts in the middle, neurogenic tumours posteriorly? Now consider the patient in front of you: would you remember to screen for compressive symptoms and for the syndromes (fatigable weakness pointing to a thymoma, a swollen plethoric face pointing to superior vena cava obstruction) that change the urgency and direction of the work-up? Reflect on why recognising that a mediastinal lymphoma is treated medically, not surgically, could spare a patient an unnecessary and harmful operation.