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A3076 - The Other ""Baby Lung"": Shrinking Lung Syndrome in the Absence of Confirmed Connective Tissue Disease
Author Block: C. Brehm1, J. M. Bishop2, K. Richardson3, D. LoVerde4; 1Internal Medicine, Wake Forest Baptist Medical Center, Winston-Salem, NC, United States, 2IM-Pulmonary, Wake Forest Baptist Health, Winston Salem, NC, United States, 3IM-Cardiology, Wake Forest Baptist Medical Center, Winston Salem, NC, United States, 4Wake Forest Baptist Medical Center, Winston Salem, NC, United States.
Shrinking lung syndrome (SLS) is a rare complication of systemic lupus erythematosus (SLE), or rarely other connective tissue disorders. SLS is characterized by lung volume reduction without parenchymal abnormalities along with restrictive pulmonary defect on pulmonary function tests (PFTs). We present a case of a patient with unexplained dyspnea attributed to SLS without SLE. 59 year old Caucasian male with history of acute myeloid leukemia, allogenic bone marrow transplant and chemotherapy presented with worsening lower extremity edema, ascites and dyspnea for three months. Cardiac magnetic resonance imaging demonstrated a thickened pericardium and a right heart catherization revealed constrictive pericarditis with tamponade. Cardiothoracic surgery performed a pericardiectomy with symptomatic improvement. One month later, he again developed progressive dyspnea, pleuritic chest pain and exercise intolerance. Physical exam revealed a thin male with alopecia, xeroderma, normal heart and lung sounds, no edema, normal spinal curvature, normal neurologic and musculoskeletal exams. PFTs were consistent with a severe restrictive defect (FEV1 41.7%, FVC 32.8%, TLC 49% and decreased DLCO). Bedside ultrasound demonstrated bilateral, normal diaphragmatic excursion. Computed Tomography of the lung was significant for a right pleural effusion (exudative), mild pulmonary edema, reduced lung volumes and no evidence of parenchymal disease. Serology was significant for an ANA 1:320 and normal dsDNA. His constellation of symptoms was consistent with SLS, however he only met two of the American College of Rheumatology criteria for SLE. Further evaluation excluded other causes of serositis and restrictive lung disease. Given his high likelihood of SLS and severe symptomatology, he was started on high dose steroids and referred to rheumatology for further workup and treatment. He had a striking response to steroids with near complete symptom resolution and is currently completing a six-month steroid taper. Given his aggregate findings and remarkable response to corticosteroids, his pathology is consistent with SLS without definitive SLE/connective tissue disease. The interesting component of this case is both the rarity of SLS, and the absence of a diagnosed connective tissue disease. SLS is described almost exclusively as a manifestation of SLE; however SLS can present anytime in the course of SLE and often without prior organ damage. The pathophysiology is thought to be related to chronic pleural inflammation leading to chronic hypoventilation and decreased compliance. Prompt diagnosis and treatment can result in symptomatic improvement. SLS should be considered in patients with unexplained dyspnea, even in patients without definitive SLE.