VEGFD and Chylothorax: Accordingly, a definite diagnosis of LAM can be established when a patient has compatible clinical and radiological findings—diffuse cystic lung disease depicted on high-resolution computed tomography (CT) of the chest—combined with one of the following features: presence of TSC, renal AMLs, chylothorax, lymphangioleiomyomas, elevated serum VEGF-D level, presence of LAM cells demonstrated in effusions or lymph nodes, or histopathological confirmation by biopsy of lung or extrapulmonary lesion.