Lymphoid Interstitial Pneumonia-like Pulmonary Infiltration in a Patient With Castleman's Disease and Sjögren's Syndrome

Abstract

INTRODUCTION: Lymphoid interstitial pneumonia (LIP) is histopathologically characterized by infiltration of the lung interstitium and alveolar spaces by lymphocytes, plasma cells, and lymphoreticular elements. We present a rare case of a LIP-like pulmonary infiltration with Castleman's disease and Sjögren's syndrome. CASE PRESENTATION: A fifty year-old man presented with one year of dyspnea on exertion and productive cough. He noted dry mouth and eyes, and arthralgias. He had a history of Castleman's disease that responded to oral steroid treatment 10 years ago. On exam, vital signs were normal, including oxygen saturation. Bilateral cervical and axillary lymphadenopathy was present. The remainder of the exam was normal. Laboratory findings were significant for a negative HIV test, protein and albumin 6.7 and 4.2 gm/dL and LDH 256 units/L. There was an increased serum kappa/lambda ratio (6.15) and kappa chain level of 62.7 mg/L. Serology showed positive anti-nuclear antibody and anti-SSA/SSB antibodies. There was diffuse bronchiectasis, bibasilar nodular infiltration and mediastinal lymphadenopathy on Chest CT (Fig 1). Excisional biopsy of a neck lymph node showed atypical lymphoid proliferation with prominent plasmatic component and Castleman's-like changes. Bone marrow biopsy was normal. Bronchoscopy with transbronchial biopsy revealed patchy peribronchial distribution of mature-appearing lymphocytes, suspicious for LIP. Open lung biopsy for definite diagnosis was not performed because his pulmonary infiltration improved with steroid treatment. DISCUSSION: LIP was considered an idiopathic interstitial pneumonia (IIP) when first described in 1966, then classified as a pulmonary lymphoproliferative disease in 1970s. Since the distinction between reactive polyclonal and neoplastic monoclonal infiltrates became discernible, LIP was re-classified as an IIP in 2000s. LIP is associated with autoimmune processes, including Sjögren's syndrome, as well as infectious organisms, including HIV, EBV, HHV-8, and HTLV. Our patient presented with pulmonary lymphocytic infiltration suspicious for LIP in the presence of both a lymphoproliferative disease and Sjögren's syndrome, highlighting the characteristics of LIP as a pulmonary manifestation of systemic diseases. To the best of our knowledge, this is the first case describing a patient with both Castleman's disease and Sjögren's syndrome associated with LIP-like pulmonary infiltration. The patient was started on steroid treatment alone and currently follows up in oncology and pulmonary clinics. CONCLUSIONS: LIP could be a pulmonary manifestation of both systemic lymphoproliferative disease and autoimmune diseases, and often needs a multidisciplinary approach to diagnosis and management.