Lymphangioleiomyomatosis (LAM) was added as a designated disease to the Specified Disease Treatment Research Program by the Japanese Ministry of Health, Labor, and Welfare in October 2009. This allowed patients to receive subsidies for medical expenses for its treatment. The criteria for designation, and a clinical research form into which doctors enter the diagnosis, were developed by the Respiratory Failure Research Group. These criteria were based on the LAM diagnostic criteria developed in 2005 by the same group. Computed tomographic findings of the lung and exclusion of other diseases were specified as required items. Although histological diagnosis is considered the gold standard, lung biopsy can be dangerous in some cases of advanced disease. Therefore, while histological diagnosis is recommended, diagnosis is also possible based on clinical findings. The disease was originally registered as "pulmonary LAM." However, it is now considered a systemic disease, and the name has been revised to the general term, "LAM".