Alpha-1 antitrypsin deficiency (A1AD or AATD) is a genetic disorder that may result in lung disease or liver disease. Onset of lung problems is typically between 20 and 50 years of age. This may result in shortness of breath, wheezing, or an increased risk of lung infections. Complications may include chronic obstructive pulmonary disease (COPD), cirrhosis, neonatal jaundice, or panniculitis.A1AD is due to a mutation in the SERPINA1 gene that results in not enough alpha-1 antitrypsin (A1AT). Risk factors for lung disease include tobacco smoking and environmental dust. The underlying mechanism involves unblocked neutrophil elastase and buildup of abnormal A1AT in the liver. It is autosomal co-dominant, meaning that one defective allele tends to result in milder disease than two defective alleles. The diagnosis is suspected based on symptoms and confirmed by blood tests or genetic tests.Treatment of lung disease may include bronchodilators, inhaled steroids, and, when infections occur, antibiotics. Intravenous infusions of the A1AT protein or in severe disease lung transplantation may also be recommended. In those with severe liver disease liver transplantation may be an option. Avoiding smoking is recommended. Vaccination for influenza, pneumococcus, and hepatitis is also recommended. Life expectancy among those who smoke is 50 years while among those who do not smoke it is almost normal.The condition affects about 1 in 2,500 people of European descent. Severe deficiency occurs in about 1 in 5,000. In Asians it is uncommon. About 3% of people with COPD are believed to have the condition. Alpha-1 antitrypsin deficiency was first described in the 1960s.
Alternatively, enlarged lymph nodes may represent a primary malignancy of the lymphatic system itself, such as lymphoma (both Hodgkins and non-Hodgkins), lymphocytic leukemia, Lymphadenopathy that lasts less than two weeks or more than one year with no progressive size increase has a very low likelihood of being neoplastic.Metastatic lymph nodes are enlarged because tumor cells have detached from the primary tumor and started growing in the lymph node ("seeded"). Since cancer generally occurs more frequently in older people, this kind of lymphadenopathy is more common in older persons. Metastatic lymph nodes tend to feel hard and may be fixed to underlying tissues and may or may not be tender. Usually the lymph nodes that directly drain the area of the cancer are affected by the spread (e.g. Sometimes metastatic cervical lymph node is detected before the main cancer). In such cases, this discovery leads to a search for the primary malignancy, firstly in the nearby area with endoscopy, "blind" biopsies, and tonsillectomy on the side of the lymphadenopathy. If no tumor is found, then the rest of the body is examined, looking for lung cancer or other possible sites. If still no primary tumor is detected, the term "occult primary" is used.In lymphoma, usually there are multiple enlarged nodes which feel rubbery to palpation. Rhabdomyosarcoma
Neuroblastoma

Other causes
Surgical trauma, e.g.