Thymoma, Pleural

Synonyms

Invasive thymoma; Malignant thymoma; Primary pleural epithelial tumor; Primary pleural thymoma

Definition

Thymomas are uncommon neoplasms that develop from thymic endothelial cells. They are the most common neoplasm of the anterior mediastinum (0.15 cases per 100,000 persons/year in the USA) and are usually found near the thymus. They are typically considered neoplasms of low malignant potential with a very slow progressive course; however, a small number do spread to local structures, like the pleura, by invasion or implants.

Thymomas can also develop from ectopic thymic tissue (4% of all thymomas), typically within the neck, the middle or posterior mediastinum, or lung. Thymomas originating in the pleura are rare occurrences and because of their location can easily be confused with other neoplasms, both radiologically and morphologically. On chest x-ray, pleural thymomas may appear as localized masses or pleural thickening with encasement of the lung. Computed tomographic...