Objectives: To evaluate comprehensively the
characteristics of lymphangioleiomyomatosis (LAM), with emphasis on the
application of imaging and immunohistochemical methods.
Design: Prospective study.
Thirty-five female subjects with LAM.
Clinical Center, National Institutes of Health.
Interventions: BAL, pulmonary function test,
ventilation/perfusion lung scans, CT of the chest and abdomen,
ultrasonography of abdomen, and immunohistochemical study of lung
Results: Most patients had
exertional dyspnea (83%) and pneumothorax (69%). BAL did not show
diagnostic changes. The most common abnormalities on pulmonary function
tests were decreased diffusing capacity of carbon monoxide (83%),
hypoxemia (57%), and airway obstruction (51%). Bronchodilator
response was found in 26% of patients. CT, which is almost
pathognomonic, showed numerous thin-walled cysts throughout both lungs
in all patients. Thirty-four patients (97%) had abnormal ventilation
and/or perfusion lung scans. An unusual “speckling” pattern was
observed on ventilation scans of 74% of patients. Common
extrapulmonary features were retroperitoneal adenopathy (77%) and
renal angiomyolipomas (60%). The percentage of abnormal smooth muscle
cells (LAM cells), reactive with HMB45, varied from 17 to 67% in 10
lung biopsy specimens.
diagnostic methods have defined the abnormalities in patients with
pulmonary LAM and increased the potential for early recognition and
treatment of this disorder. Patients with LAM should be evaluated for
bronchodilator responsiveness and may benefit from a trial of
Dlco = diffusing capacity of the lung for carbon
monoxide; ELF = epithelial lining fluid;
LAM = lymphangioleiomyomatosis