Introduction: Lymphangiomyomatosis (LAM) is a low-grade destructive tumor that diffusely involves lungs in women of reproductive age. Some cases have been reported in post-menopausal women as well as in men with tuberous sclerosis. About 1% of patients with tuberous sclerosis have changes similar to LAM in their lungs. About 15% of patients with LAM have tuberous sclerosis. Clinical Presentation:The patients usually present with dyspnea on exertion and are prone to developing pneumothorax and chylous pleural effusions. They may also have chylous ascites, chyluria, renal angiomyolipomas and retroperitoneal lymphadenopathy. Gross Pathology: With lung involvement, there is formation of numerous uniform thin-walled cysts and bullae throughout the lungs creating a honeycomb appearance. The image shows extensively cystic lung parenchyma in a 29 y/o female with LAM who underwent bilateral lung transplantation. Image copyright: pathorama.ch.