Pleural thymoma: Radiological and histological findings

Epithelial thymic tumors (thymoma and thymic carcinoma) are rare neoplasms. The incidence of thymomas is estimated to be 0.15 cases per 100.000 persons/year in the USA [1] and it represents less than 1% of primary malignancies in adults. However, it remains the most common primary neoplasm of the anterior mediastinum, accounting for 20% of tumors in this location [2]. Ectopic thymomas have been described in the neck, middle mediastinum, posterior mediastinum, lung and pleura; few reports have described giant intrathoracic tumors, but they account only 4% of all thymomas [3,4]. Usually, about 70% of patients with thymomas remains asymptomatic; the rest of patients may present local symptoms related to tumor encroaching on surrounding structures like cough, chest pain, superior vena cava syndrome, dysphagia, and hoarseness of voice. Only 30% of patients with thymoma has clinic related to myasthenia gravis. An additional 5% of patients have other systemic syndromes including red cell aplasia, dermatomyositis, systemic lupus erythematous, Cushing syndrome and syndrome of inappropriate antidiuretic hormone secretion (SIHAD) [5]. The aim of this report is to describe the main radiological finding on X-ray, computed tomography (CT) and positron emission tomography (PET), in a case of pleural thymoma. We also report how perform radiological thymoma staging.