Pulmonary lymphangioleiomyomatosis: high-resolution CT findings

Lymphangioleiomyomatosis (LAM) of the lung is a very rare disease. There ar e obvious discrepancies in the literature concerning the appearance of LAM on CT scans of the lung. This study adds the imaging findings of 11 patient s and demonstrate; how the imaging findings changed over time in four patie nts. Twenty-two CT examinations, and radiographs that had been obtained clo se to the CT examinations, of 11 patients with LAM confirmed by open lung b iopsy were retrospectively evaluated with particular a:attention to the siz e of cystic lesions and wall thickness. Furthermore the CT scans were analy sed for the type of pulmonary infiltration process and its distribution, pr esence or absence of pleural presence or absence of pleural effusion,pneumo thorax and lymph node enlargement. Clinical and CT follow-up studies were a vailable four patients. The CT scans revealed an increase in the interstiti al pattern in all patients. Architectural distortion was seen in two patien ts and cystic lesions were present in all. The size of the cysts varied fro m small lesions to bullous emphysema. The cystic lesions revealed a wall th ickness up to 2 mm but a wall was not perceptible in all. Pneumothorax was seen in only two patients; pleural effusion was seen in two patients. CT ex amination of patients with LAM reveals neither a uniform nor a pathognomoni c appearance. In the early stages of LAM or in cases with interstitial chan ges the differential diagnosis of centrilobular emphysema or idiopathic pul monary fibrosis seems to be more difficult than most authors believe.