THYMOMA PRESENTING AS AN INTRAPULMONARY MASS

TYPE: Abstract Publication TOPIC: Disorders of the Mediastinum PURPOSE: Thymic malignancies are rare epithelial tumors mostly arising in the anterior mediastinum. Thymomas may be associated with autoimmune disorders, such as myasthenia gravis. METHODS: An 81 year-old-male patient, non-smoker, with previous history of parkison’s disease, referred to General Pulmonology consultation for asthenia, chest pain and changes in chest CT – a left upper lobe enhancing mass adjacent to the pleura measuring 45x16 mm and a large right paracardiac enhancing mass measuring 51x37 mm with pericardial invasion. There were no solid lesions in the anterior mediastinum or associated adenopathies. On physical examination, respiratory sounds were diminished in the right lower lung field, but no other abnormalities were detected. A PET CT was performed, that showed an intense metabolically active (SUVmax=6,7) right middle lobe mass with ipsilateral mediastinal node metastasis. At this point, a bronchofibroscopy was done, that showed mucosa with infiltrative signs in the right lower lobar bronchus. The bronchial aspirate was negative for neoplastic cells and the biopsies revealed non-specific chronic inflammation. Subsequently, the patient underwent a transthoracic needle biopsy, that was inconclusive. The biopsy was repeated and the histology was consistent with type B1 thymoma. RESULTS: The patient was referred to the Oncology Centre for further management. CONCLUSIONS: Though rare, thymoma may present as an intrapulmonary mass. CLINICAL IMPLICATIONS: A thymoma can occur widely in locations derived from the pharyngeal pouch and should always be considered in differential diagnosis of an undefined neoplasm, even those in the middle mediastinum. Major prognostic factors include tumor stage, completeness of surgical ressection and histology. DISCLOSURE: No significant relationships. KEYWORDS: mediastinum, thymoma, intrapulmonary mass