Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
Up to 50% to 60% of patients with thymoma will have a so-called paraneoplastic syndrome, a medical condition not involving the thymus that is associated with (probably caused by) the thymoma. The most commonly associated condition with thymoma is myasthenia gravis.
Thymomas are slow-growing tumors, and the prognosis is excellent when they are discovered in their early stages.
Surgical removal is the mainstay of treatment.
What is thymoma?
A thymoma is an uncommon tumor or cancer of the thymus gland. The thymus is a gland located in the anterior mediastinum (the area between the lungs in the chest) that plays a critical role in the development of immune cells during childhood. The thymus gland enlarges during childhood, peaks in size at puberty (about 40 grams) and begins to shrink after an individual reaches puberty.
Normally, the thymus is made up of a combination of lymphoid cells (immune cells or lymphocytes) and lining cells (epithelial cells). Thymoma is a tumor that originates from the epithelial cells of the thymus. The term thymomic neoplasms is used to refer to tumors of the thymus, which consist of thymomas and thymic carcinomas. Thymic carcinomas are tumors of the thymus having cells with a markedly abnormal appearance under the microscope. Thymic carcinomas are more aggressive than thymomas (they are more malignant), but they account for only about 1% of thymic tumors.
Thymoma: a rare type of tumor that is the most common tumor type located in the area in the center of the chest between the lungs (the anterior mediastinum). Thymomas originate from epithelial cells in the thymus, a gland located behind the breast bone in the mediastinum, which is responsible for the development of many immunologic functions in early life. The thymus contains both lymphoid (immune) cells and lining (epithelial) cells and begins to reduce in size after an individual reaches puberty. The cells of thymomas appear similar to normal thymus cells, while cancers of the thymus have abnormal, cancerous-appearing cells. Cancers of the thymus (thymic carcinomas) have a much greater tendency to spread to other areas of the body than thymomas. Myasthenia gravis and also other autoimmune diseases have been associated with thymoma.