Benign lesions of the mediastinum

Abstract

Mediastinal tumours represent a heterogeneous group of entities derived from the manifold structures located in or adjacent to the mediastinum. Due to the occurrence of some of these tumours in characteristic mediastinal compartments, an anatomical subdivision of the mediastinum in the prevascular (anterior), visceral (middle), and paravertebral (posterior) is helpful for the differential diagnosis. Benign anterior mediastinal tumours linked to an enlargement of the thymic gland mainly consist of thymic cysts and several types of thymic hyperplasia: true thymic hyperplasia, rebound hyperplasia, lymphofollicular hyperplasia, and so‐called thymic hyperplasia with lymphoepithelial sialadenitis (LESA)‐like features. Mature teratomas, ectopic (para)thyroid tissue, and benign thymic tumours such as thymolipoma or thymofibrolipoma represent further typical tumours of the anterior mediastinum. Pericardial, bronchogenic, or oesophageal duplication cysts predominate in the middle mediastinum, whereas neurogenic tumours and myelolipomas are characteristic findings in the posterior compartment. Vascular tumours, lipomas, adenomatoid tumours, Castleman disease, or mediastinitis are further examples of less frequent tumours or tumorous lesions affecting the mediastinum. This review focuses on benign mediastinal lesions with an emphasis on benign tumours of the thymus. Besides histology, characteristic epidemiological and clinical aspects prerequisite for the correct diagnosis and patient management are discussed.

Personalized Management of Malignant and Non-Malignant Ectopic Mediastinal Thyroid: A Proposed 10-Item Algorithm Approach

“…Metastatic lesions showing a follicular thyroid pattern may be originating from the EMT or cervical thyroid malignancies. An immunohistochemistry report (thyroglobulin, PAX8, TTF1, Ck7, and even lymphoma immune phenotyping) [55] adds value in confirming the thyroid profile in EMTs, especially in cases when pre-operatory or pre-biopsy investigations (particularly, iodine or 99m-Tc scintigraphy) were not consistent with a confirmation of ectopic thyroid tissue or in subjects suspected or confirmed with other malignancies [186][187][188][189][190].…”