PRIMARY SJOGREN SYNDROME CAUSING PULMONARY EXTRANODAL MARGINAL CELL LYMPHOMA

Abstract

SESSION TITLE: Medical Student/Resident Lung Pathology SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Extranodal marginal zone lymphoma (MZL) of the lung is a rare pulmonary lymphoid malignancy and World Health Organization (WHO) classifies Mucosa associated lymphoid tissue (MALT) lymphoma as a subtype of B-cell MZL. CASE PRESENTATION: 80 year old Caucasian male with past medical history of obstructive sleep apnea, chronic kidney disease stage III, type II diabetes mellitus, hypertension and tobacco abuse, was first seen in pulmonary clinic for asymptomatic innumerate bilateral pulmonary nodules noted on Computed Tomography (CT) scan of the chest. He complained of occasional chronic dry mouth on further questioning. Antibody testing was positive for Antinuclear antibodies (245 AU/ml) and SS Ro antibody (188 AU/ml). His dry mouth and lower lobe predominant cystic and nodular changes were concerning for lymphoid interstitial pneumonia associated with Sjogren's syndrome. He was referred to rheumatology then subsequently lost to follow up. He presented two years later with increased shortness of breath and progressive weight loss. Pulmonary function tests (PFTs) showed an isolated low diffusing capacity for carbon monoxide at 33% predicted (down from 75% prior). CT scan revealed progression of his bilateral lung nodules and cystic changes in the lower lungs bilaterally. He then underwent bronchoscopy and surgical lung biopsy. This showed a low-grade B- cell lymphoma with plasmacytic differentiation, most consistent with MALT stage 1E Extranodal marginal zone lymphoma. Patient was started on rituximab weekly for 4 weeks and reported some improvement in his sicca symptoms. DISCUSSION: Roughly 10 to 20 percent of SS patients have clinically significant lung disease defined by symptoms most commonly cough and dyspnea. Abnormal imaging and PFTs are common. Thin-walled lung cysts are detected with CT imaging in 12 to 46 percent of SS patients. Interstitial lung disease can occur in SS in several forms (1). In a series of thirteen patients with pulmonary MALT lymphoma performed by Yachoui et. al, 54% were positive for primary sjogren syndrome (PSS) (2). No difference in outcomes was noted on two large retrospectives studies involving different treatment modalities including surgery, chemotherapy or combined therapy. Asymptomatic patients should be observed with no treatment indicated initially. It is indicated for patients with a high burden of lymphadenopathy with splenomegaly, organ dysfunction, bone marrow suppression, and/or rapid disease progression (3). Series performed by Yachoui et. al demonstrated a favorable prognosis in all cases of pulmonary MALT lymphoma with all treatment modalities resulting in complete and sustained response (2). CONCLUSIONS: SS can have wide ranging organ involvement. Prompt referral to rheumatology and active monitoring is paramount. Further investigation is warranted to better understand pulmonary MALT pathogenesis, treatment, and outcomes in PSS. Reference #1: Stojan, G., et al. (2013). “Pulmonary manifestations of Sjögren's syndrome.” Current allergy and asthma reports 13(4): 354-360. Reference #2: Yachoui R, Leon C, Sitwala K, Kreidy M. Pulmonary MALT lymphoma in patients with Sjögren's syndrome. Clinical medicine & research. 2017;15(1-2):6-12. Reference #3: Pinotti G, Zucca E, Roggero E, Pascarella A, Bertoni F, Savio A, et al. Clinical features, treatment and outcome in a series of 93 patients with low-grade gastric MALT lymphoma. Leukemia & lymphoma. 1997;26(5-6):527-37