A 65-year-old man, former smoker, was examined in the respiratory medicine clinic in 2009 due to density in the right cardiophrenic angle on an imaging study. A chest CT revealed a solid mass 29×34mm, with smooth, well-defined margins, suggestive of pleuropericardial cyst. The patient did not return to the clinic until September 2015, when a follow-up chest radiograph revealed that the previously observed lesion had increased in size (Fig. 1). Chest CT showed a solid mass in the right cardiophrenic angle, with a diameter greater than 6cm, associated with a probable pleural fibrous mass (Fig. 1). This lesion was subsequently surgically resected. The pathology study was consistent with a pseudoencapsulated thymoma, WHO type AB, with clear surgical margins.
Both the WHO and the Masaoka classification systems have been widely used to organize and classify epithelial tumors of the thymus, including thymomas and thymic carcinomas. However, the International Association for the Study of Lung Cancer (IASLC) and the International Thymus Malignancies Interest Group (ITMIG) have proposed a new classification for the next edition of the TNM classification of malignant tumors.1 With regard to site, 90% of thymomas occur in the anterior mediastinum and 6% in the upper mediastinum. The remaining 4% can develop ectopically in the neck, posterior mediastinum and the lung. The finding of an ectopic thymoma in the pleura or in the pericardium is extremely rare.2,3
Please cite this article as: Cerezo Lajas A, Rodríguez Guzmán Romero de Hombrebueno MC, de Miguel Díez J. Timoma de localización atípica. Arch Bronconeumol. 2017;53:209.
