Ectopic thymoma presenting as a large intrathoracic mass

Thymoma is an epithelial neoplasm of the thymus, which commonly lies in the anterior mediastinum. Unusually it can be found in other locations as well. Ectopic thymoma rarely presents as an intrathoracic tumor. We report a case of an ectopic thymoma presenting as a giant right intrathoracic tumor that was treated with resection. The patient was a 49-year-old postmenopausal lady who presented with heaviness in chest and breathlessness. Detailed investigation including chest computed tomography scan and magnetic resonance imaging revealed a well-defined large solid tumor in the right thoracic cavity. Surgery was performed based on the radiological findings. A large solid tumor measuring 12 cm x 10 cm x 8 cm was found in the thoracic cavity, adherent to the pericardium, diaphragm and the right mediastinal pleura without apparent invasion. The tumor was completely resected. The diagnosis given as World Health Organization classification-Type B1 Muller-Hermelink classification-predominantly cortical thymoma.