Pulmonary lymphangiomyomatosis is a specific clinical and pathological disease, though it is rare. It is composed of a hamartomatous proliferation of smooth muscle around the lymphatic vessels of the lung, mediastinum, and retroperitoneum and may occur in menstruating women. It may appear as a pneumothorax or chylous pleural or abdominal effusion.
Pulmonary function testing is the simplest and most practical method of assessing the severity of lung disease in lymphangioleiomyomatosis. Airflow obstruction and decreased lung diffusion capacity are the most frequent pulmonary function abnormalities. Evidence of airflow limitation is often discovered in over 60% of patients. It was less frequent in about one-third of patients who have normal pulmonary function tests. In some cases, the most frequent abnormality in pulmonary function is a decrease in lung capacity, which is often seen in 80% of patients. Though most patients have both airflow obstruction and impaired gas exchange, a significant number have normal airflow or only mild airflow obstruction, along with a markedly less diffusion capacity. In these patients, the severity of the disease should be ranked through tests of gas exchange such as DLCO, arterial blood gases, alveolar-arterial oxygen (A-a/O2) gradient, cardiopulmonary exercise testing or a 6-minute walk test, to recognize and treat hypoxemia.
