Thymoma is a rare tumor originating from the epithelial cells of the thymus gland, located in the anterior mediastinum. It is often associated with paraneoplastic syndromes, particularly myasthenia gravis, but can also be asymptomatic. Classification is based on histology (e.g., A, AB, B1, B2, B3, C) and staging (Masaoka-Koga system) determines prognosis and treatment. Management typically involves surgical resection, with adjuvant radiation or chemotherapy for advanced stages.