MEDRADSC 2T03 Lecture Notes - Lecture 3: Myasthenia Gravis, Mediastinum, Hypogammaglobulinemia
Document Summary
Rare - 0. 2% to 1. 5% of all malignancies. Most common neoplasm of the anterior mediastinum: 20-25% of all mediastinal tumors, 50% of anterior mediastinal masses. Most common in asians and pacific islanders. More common in african americans than in whites. The thymus is a gland in the upper part of the chest, just behind the sternum and between the lungs. It has an irregular shape and a surface that is made up of many lobules. The medulla is the innermost part of the thymus. The cortex is the layer surrounding the medulla. The capsule is the thin covering over the outside of the thymus. The thymus reaches its maximum weight of about 1 ounce during puberty, then slowly decreases in size during adulthood as it is gradually replaced by fat tissue. The thymus is an important part of the immune system. The bone marrow releases lymphocytes into the blood stream.