Lymphangiomatosis is a disease in which many tumors or cysts grow in the lymph system of the body. The lymph system extends to every major organ system except the brain and central nervous system. Though they are not cancerous, they invade body tissues and cause pain, difficulty breathing, and other symptoms depending on their location. It can affect anyone at any age, but is most commonly diagnosed in children and almost always before age 20. When a cyst or tumor is in the lungs or chest, symptoms may include dry cough, shortness of breath, wheezing, chest pressure, chest pain, and coughing up blood. Diagnosis may involve X-rays and other scans that show the affected organs or a biopsy to study a tissue sample. There are several surgical, medicinal, and nutritional strategies that may be personalized to treat each individual’s lymphangiomatosis.