Cysts in Lung: A Diagnostic Challenge

Abstract

INTRODUCTION: Sjogren's Syndrome (SS) is a rare cause of cystic pulmonary lesions. On the other hand 75% of patients who have primary SS may have pulmonary manifestations. CASE PRESENTATION: A 53 yo caucasian woman presented with incidental findings of cystic lesions at the lung bases. The otherwise athletic patient has history of hypothyroidism, miscarriages, GERD, silicone implants, rosacea, SS diagnosed at age of 26 with symptoms of keratoconjunctivitis sicca, xerostomia and recurrent parotid swelling. She does not have history of pneumothorax. Patient had domesticated birds at her farm. She never smoked and had no significant family history. Exam revealed rosacea, decreased salivary pool, normal sized lung fields without adventitious sounds. PFTs revealed mild restrictive pattern with DLCo 73% predicted. Imaging(HRCT): Numerous cystic changes scattered throughout both lungs, with normal surrounding parenchyma. Labs:beta2 microglobulin, RVVT, antibodies against CCP, Cardiolipin, beta2 Glycoprotein, Scl-70, endomysium, Sm, RNP, DNA were all negative.ANA,anti-SSA and SSB antibodies were positive.Aspergilus Flavus and anti-avian antibodies were also positive. Lung Biopsy: Peribronchial and perivascular lymphocytic aggregates and patchy deposition of material, which was Congo red stain negative. No abnormal smooth muscle cells seen. Diagnosis: SS related cystic lung disease. Likely ILP type vs other types. Progress over 3 years: Despite trial of corticosteroids and mycophenolate, DLCo has dropped from 70s to late 50s. DISCUSSION: In the present case with scattered lung cysts surrounded by preserved lung parenchyma on HRCT, lymphangiomyomatosis was a reasonable initial possibility. Lung biopsy did not reveal any abnormal smooth muscle cells. Possibility of burnt out hypersensitivity pneumonitis as significant bird exposure and positive anti-avian antibodies was there, but lower on the list in absence of other symptoms. ABPA considered unlikely as IgE normal and no significant obstructive pattern. Biopsy analysis suggested possible lymphocytic interstitial pneumonia vs other SS associated cystic lung disease.Amongst the pathological patterns, NSIP is the commonest and has the best HRCT-Pathology correlation as compared to HRCT non-NSIP patterns. Five year survival in a retrospective study was found to be 84%. Corticosteroids and immunosuppressants can be tried for life threatening pulmonary conditions, but consensus guidelines are lacking. CONCLUSIONS: It is important to include Sjogren's Syndrome as one of the differentials for cystic lung disease specially when other common causes have been ruled out. Understanding regarding natural history, prognosis and treatment is limited so far.