An invasive primary thymoma : a rare cause of intrapulmonary mass

Background: Primary intrapulmonary thymomas are extremely rare tumors and could be mistaken for a variety of benign and malignant epithelial or mesenchymal lesions. Case report: A case of a primary invasive intrapulmonary thymoma manifested with massive hemoptysis is presented. CT demonstrated a mass with specks of calcification, located within the upper lobe of the right lung. The lesion showed heterogeneous enhancement with areas of cystic and necrotic degeneration and hemorrhagic foci. CT differential diagnosis included the possibility of invasive thymoma, which was confirmed by surgery and histopathology. Conclusions: Though a rare entity, intrapulmonary thymoma, because of its potentially invasive and malignant nature, should be included in the radiological differential diagnosis of intrapulmonary masses. This is important, since it can determine further management.