ACUTE FIBRINOUS ORGANIZING PNEUMONIA: A NEW ASSOCIATION

Abstract

TOPIC: Lung Pathology TYPE: Fellow Case Reports INTRODUCTION: Acute Fibrinous and Organizing Pneumonia (AFOP) is a rare histological pattern of acute lung injury of unclear etiology. It can present with severe hypoxemia and characteristic bilateral basilar infiltrates meeting criteria for acute respiratory distress syndrome(ARDS). We present the case of a 48-year-old female with ARDS who was diagnosed with AFOP after an open lung biopsy. CASE PRESENTATION: A 48-year-old female with a past history of schizophrenia, hypertension, type 2 diabetes, osteoarthritis and monoclonal gammopathy of undetermined significance (MGUS) presented with cough and progressive shortness of breath, worsening acutely over three days. Upon arrival, the patient was hypoxic with oxygen saturation of 47%, on room air so she was emergently intubated. Initial chest X-ray revealed bilateral mid to lower zone infiltrates concerning for severe pneumonia (Picture 1). Chest CT-Angiogram ruled out pulmonary embolism. She was admitted to our intensive care unit and started on empiric broad spectrum antibiotics (Vancomycin/Piperacillin-Tazobactam/Levaquin) and ventilated using a lung-protective strategy for ARDS. Over the next 15 days, she remained ventilator dependent with high FiO2/PEEP requirements and eventually had a tracheostomy. Microbiological studies including bronchoscopic samples remained negative. An open lung biopsy was performed which showed lymphocyte and plasma cell infiltration and intra-alveolar fibrin balls with an absence of neutrophil/eosinophil infiltration and hyaline membrane formation typical of other well-recognized patterns of acute lung injury, leading to a diagnosis of AFOP (Picture 2). She was started on high dose steroids (methyprednisolone 60mg IV q8h) with prompt resolution of infiltrates and improvement in her oxygenation. DISCUSSION: (AFOP) is a rare histologic pattern of acute lung injury with multiple clinical associations but unclear etiology. Two clinical patterns have been described: i) an acute fulminant condition with severe hypoxemia and ii) a subacute respiratory illness. Diagnosis requires biopsy revealing intra-alveolar fibrin balls amidst an organizing pneumonia. AFOP has been described in patients with HIV infection, decitabine exposure, amiodarone toxicity, post hematopoietic stem cell transplantation, connective tissue diseases etc. Patients have been treated with corticosteroids, mycophenolate mofetil, cyclophosphamide, and cyclosporine with variable response. [1] CONCLUSIONS: In this case, monoclonal gammopathy of unknown significance (MGUS) represents a new association of AFOP and thus adds to our understanding of the clinical and pathological characteristics of this disease. REFERENCE #1: 1. Acute fibrinous and organizing pneumonia and undifferentiated connective tissue disease: a case report. Valim V, Rocha RH, Couto RB, Paixão TS, Serrano EV. Case Rep Rheumatol. 2012;2012:549298. doi: 10.1155/2012/549298. Epub 2012 Apr 4. DISCLOSURES: No relevant relationships by Sukhmani Boparai, source=Web Response No relevant relationships by Prangthip Charoenpong, source=Web Response No relevant relationships by Deon Ford, source=Web Response