A benign neoplasm that involves the thymus. The disease is benign neoplasm of thymus (MONDO_0021512). Also known as: benign Thymus neoplasm, benign Thymus tumor, benign Thymus tumour, benign neoplasm of the Thymus, benign thymic neoplasm, benign thymic tumor, benign thymic tumour, benign tumor of Thymus.