Stato dell'arte sulla LAM

Lymphangioleiomyomatosis (LAM) is a rare disease that affects predominantly females. The main feature of the disease is the abnormal proliferation of smooth muscle-like cells (LAM cells) leading to the formation of thin-walled cysts in the lungs and in the axial lymphatics (lymphangioleiomyoma). It is also characterized by angiomyolipomas, benign tumors of the kidneys composed of smooth muscle cells, adipocytes and incomplete blood vessels. The prevalence of the sporadic disease is about 2,6 per million in the USA. LAM arises in 30% of females with tuberous sclerosis complex. The most common clinical manifestation at onset is dyspnoea in association or not with cough or haemoptysis. Chest-x ray is characterized by reticular changes even if it is usually normal in early disease. High resolution CT is the main diagnostic tool. It shows the presence of lung round thin-walled cysts. The cysts range in size from barely perceptible to several centimeters and are scattered throughout the lungs without lobar predominance. The most common functional alteration is obstructive impairment in association with decreased DLCO due to alteration of elastic recoil of the lung. Hormonal therapy has been considered in the past years but its efficacy has not been proved. Rapamycin and its derivatives have been trialed with positive results. In advanced disease oxygen and lung transplantation may be necessary.