WHEN LIGHTNING STRIKES TWICE: A CROSSOVER SYNDROME WITH LIGHT CHAIN DEPOSITION AND LYMPHOID INTERSTITIAL PNEUMONIA

Abstract

SESSION TITLE: Medical Student/Resident Diffuse Lung Disease SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Light chain deposition disease (LCDD) is a rare cystic lung disease, involving monoclonal proliferation and deposition of light chains. Lymphoid Interstitial Pneumonia (LIP) is an uncommon interstitial lung disease (ILD) usually seen with connective tissue disorders (CTD). We present a challenging case involving the co-existence of LCDD and LIP. CASE PRESENTATION: We present the 25-year long clinical course of a 47-year-old male who was initially diagnosed with a mucosa-associated lymphoid tissue (MALT) lymphoma of the parotid gland, treated with excision. Over the subsequent 5-10 years, he was diagnosed with rheumatoid arthritis and Sjogren’s syndrome. Treatment with methotrexate was complicated by the development of human anti-murine antibodies. He also developed progressive cough and dyspnea. Computed Tomography (CT) imaging of the chest revealed bilateral nodules and interstitial infiltrate, suggestive of LIP. Right lower lobe wedge resection was performed; histopathology demonstrated lymphoplasmacytic infiltrate and eosinophilic proteinaceous deposits which were negative on Congo red staining. Immunohistochemistry revealed predominantly kappa light chains within the eosinophilic material. Serial follow-up imaging was notable for the development of diffuse cystic lung disease. He was diagnosed with LCDD and was treated with bortezomib, but developed Steven-Johnson syndrome. This was followed by treatment with lenalidomide and then cyclophosphamide. A follow up positron emission tomography (PET) CT scan showed no change in the size of pulmonary nodules. The patient was also trialed on bendamustine and ofatumumab, an anti-CD20 monoclonal antibody, with no significant improvement. A recent chest CT, obtained 15 years following the onset of lung disease, demonstrated wide-spread thin walled cysts and nodular disease (Fig 1,2). His symptoms have stabilized with oxygen supplementation and treatment of exacerbations with steroids and antibiotics, and he is currently on surveillance. DISCUSSION: LCDD, an entity caused by plasma cell proliferation and monoclonal light chain deposits in various organs often found in association with lymphoproliferative conditions, can manifest as diffuse cystic lung disease. (1) It has a poor prognosis. Treatment options include immunomodulators and chemotherapeutic agents, including bortezomib, daratumumab, and bendamustine. LIP, an ILD, is usually seen in patients with CTD and HIV. (2) Therapeutic options include immunosuppressants such as rituximab and cyclophosphamide. Our case was challenging, given the confluence of two syndromes- LIP with underlying rheumatic conditions, and LCDD due to a lymphoproliferative disorder. Multiple avenues of treatment were attempted but failed to produce an objective improvement in disease course. CONCLUSIONS: LIP and LCDD can occur in tandem; enrollment in study trials should be considered for these patients given poor prognosis. Reference #1: Arrossi AV, Merzianu M, Farver C, et al. Nodular pulmonary light chain deposition disease: an entity associated with Sjögren syndrome or marginal zone lymphoma. J Clin Pathol. 2016 Jun;69(6):490-6. Reference #2: Swigris JJ, Berry GJ, Raffin TA, et al. Lymphoid interstitial pneumonia: a narrative review. Chest. 2002 Dec;122(6):2150-64. DISCLOSURES: No relevant relationships by Pius Ochieng, source=Web Response No relevant relationships by NISHANT SHARMA, source=Web Response No relevant relationships by Pandi Todhe, source=Web Response