Pulmonary lymphangiomatosis, or simply lymphangiomatosis, is a rare disorder that is believed to be congenital (people are born with it) and can affect any of the body's systems except the central nervous system (including the brain). It is a disease of the lymphatic system, which is a network of vessels that circulate fluid besides blood through the rest of the body and also work as part of the body's immune system. Pulmonary lymphangiomatosis can affect anyone at any age, but it is most commonly diagnosed in children and almost always before age 20. Symptoms include chest pain and pressure, coughing up blood and shortness of breath. Talk with your doctor to find the best treatment if you or your child has been diagnosed with pulmonary lymphangiomatosis.