==== Front Ann Saudi MedAnn Saudi MedAnnals of Saudi Medicine0256-49470975-4466King Faisal Specialist Hospital and Research Centre 2379343610.5144/0256-4947.2013.301asm-3-301Case ReportAcute fibrinous and organizing pneumonia Al-Khouzaie Thamer H. aDawamneh Mohamad F. bHazmi Albader M. c a Internal Medicine Services Division, Saudi Aramco Medical Services Organization (SAMSO), Dhahran Health Center (DHC), Dhahran, Saudi Arabia b Pathology Service Division, Saudi Aramco Medical Services Organization (SAMSO), Dhahran Health Center (DHC), Dhahran, Saudi Arabia c Radiology Service Division, Saudi Aramco Medical Services Organization (SAMSO), Dhahran Health Center (DHC), Dhahran, Saudi ArabiaCorrespondence: Thamer H. Al-Khouzaie, MD, ARAMCO, P.O Box 119799, Dhahran 31311, Saudi Arabia, T:+96638777794, F: +96638773790, thamer.khouzath@aramco.com.saMay-Jun 2013 33 3 301 303 Copyright © 2013, Annals of Saudi Medicine2013This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.A 45-year-old man presented with malaise, arthralgia, and dyspnea. The chest CT scan showed bilateral patchy consolidation in the lower lobes. A lung biopsy revealed intra-alveolar fibrin “balls” deposits and focal features of organizing pneumonia, both of which are typical pathological features of acute fibrinous and organizing pneumonia (AFOP). The patient had a good clinical course after treatment with prednisone. We report this case of idiopathic AFOP and review the published studies on this newly recognized clinicopathological entity that is still underdiagnosed and underreported. ==== Body Acute fibrinous and organizing pneumonia (AFOP) was first described by Beasley et al in 2002, as a new pattern of lung injury, with histological similarities to organizing pneumonia (OP), diffuse alveolar damage (DAD), and eosinophilic pneumonia (EP). However, it has a distinct overall histological pattern, characterized by intra-alveolar fibrin associated with OP in a patchy distribution. Since Beasley’s initial description, 14 individual case reports of AFOP have been published in English research papers. Although the histopathological features are well described, the clinical manifestations, course, and treatment of AFOP are not characterized. We report a case of a male with bilateral patchy lower lobes consolidation, in which lung biopsy revealed the classical histopathological features seen in AFOP. CASE A 45-year-old man, without significant past medical history, presented with a history of malaise and arthralgia of 8 weeks duration preceded by a flu-like illness. Two weeks prior to his presentation to the emergency room, he complained of left-sided chest pain with dyspnea and nonproductive cough. There was no history of fever, chills, sweats, hemoptysis, or weight loss. Neither a history suggestive of connective tissue diseases was available nor significant occupational or environmental exposure was reported. On examination the patient was alert with temperature of 37.2°C, pulse rate 100/min, respiratory rate 18/min, and blood pressure 130/60 mm Hg. He appeared lethargic but without obvious signs of respiratory discomfort. Auscultation of the lungs revealed bilateral inspiratory crackles. The rest of his physical examination was unremarkable. Laboratory data revealed a white blood count of 9.8 k/cu mm, white blood count of 9.8×109 (4–10×109) hemoglobin 11.9 g/dL, and platelet count of 546k/mm3. The ESR was 34 mm/h. Electrolytes, creatinine, liver function tests, and urine analysis were within normal limits. A sputum gram smear showed scant neutrophils, and a sputum culture detected a growth of normal respiratory flora. Arterial blood gas at room air revealed pH 7.4, PaO2 63 mm Hg and a PaCO2 35 mm Hg. Serologic tests for ANA, RF, and C-ANCA and P-ANCA were negative. The pulmonary function test revealed a moderate restrictive ventilatory impairment and a moderate decrease in diffusing capacity. A chest CT scan revealed bilateral patchy peripherally located consolidations, mainly of the lower lobes. Some consolidations appear nodular with thickening of the interlobular septae (Figure 1). An open lung biopsy from the left lower lobe revealed a patchy consolidation of the lung parenchyma with interstitial thickening associated with a mixed inflammatory infiltrate of mononuclear cells and a few neutrophils (Figure 2). Some alveoli contained fibrin deposits as “fibrin balls” admixed with macrophages (Figure 3). Focal features of OP were present and characterized by intraalveolar fibroblastic plugs (Figure 4). Some alveoli were lined by reactive and hyperplastic pneumocytes. The intervening parenchyma between the consolidated areas showed mild interstitial thickening, sparse inflammatory infiltrate, and focal emphysematous changes. Subpleural fibrosis and chronic inflammation were present. No hyaline membranes were seen. The special stains for fungal and mycobacterial organisms were negative. These findings were consistent with AFOP. After establishing the diagnosis of AFOP, the patient was started on methylprednisone 60 mg every 6 hours, followed by 50 mg of oral prednisone daily. He showed substantial clinical and radiological improvements after 12 weeks of corticosteroid treatment. The chest scan revealed almost normal findings after 3 months (Figure 5). DISCUSSION From the 17 cases that comprised Beasley’s initial report of AFOP, which were identified by a retrospective review of case material at the Armed Forces Institute of Pathology, 9 cases had fulminating illness and died of the disease, and 8 cases had a subacute disease with recovery. The most common symptoms reported were dyspnea in 11 patients, fever in 6 patients, and cough in 3 patients. Bilateral basilar infiltrates were the most common radiographic pattern. Seven of the 17 patients were treated with corticosteroids. Fourteen individual case reports of AFOP have been published in English,2–15 after Beasley’s initial description. All patients had symptoms for less than 2 months, with cough and dyspnea as the most common. Radiographic abnormalities included bilateral basilar infiltrates in 11 patients,2,3,5,7–15 while unilateral complete lung consolidation solitary nodule,4 miliary nodules, and patchy consolidations6 were noted in the remaining 3 patients. Identified exposures or associated conditions included medications (abacavir and decitabine),5,10 connective tissue disease,8,11 hematopoietic stem cell transplant,6 acute lymphoblastic leukemia,13 HIV,7 juvenile dermatomyositis,3 and Whipple disease.15 No underlying cause or association were identified in 5 cases.2,4,9,12,14 Patients were treated with medications including corticosteroids, mycophenolate mofetil, cyclophosphamide, and cyclosporine. Among the 14 case reports, 3 patients required mechanical ventilation,3,5,9 and 2 patients died.3,6 In addition to these individual case reports, Hwang et al16 reported autopsy finding from the lungs of 20 patients who died from severe acute respiratory syndrome. The histological findings of these 20 patients were AFOP pattern in 6 cases, DAD in 8 cases, and both patterns in the remaining cases. In conclusion, AFOP is a newly recognized clinicopathological entity that is still underdiagnosed and underreported. Although the histopathological features are well described, identification of precipitating factors, clinical course, and elements affecting prognosis and treatment need to be fully established. Acknowledgments The authors acknowledges the use of Saudi Aramco Medical Services Organization (SAMSO) facilities for the research data utilized in this manuscript. Opinions expressed in this article are those of the authors and not necessarily those of SAMSO. Figure 1 Chest CT scan revealed bilateral patchy peripherally consolidations locatedmainly in the lower lobes with some appearance of nodular plus thickening of the interlobular septae. Figure 2 Alveolar interstitial thickening with inflammatory infiltrate including neutrophils (H&E stain, ×20). Figure 3 Consolidated pulmonary parenchyma with intra-alveolar fibrin deposits “fibrin balls” (H&E stain, ×20). Figure 4 Organizing pneumonia with intra-alveolar fibroblastic plugs (H&E stain, ×20). Figure 5 CT scan after three months of corticosteroid therapy shows significant improvement with almost complete resolution of most of the previously seen findings. ==== Refs REFERENCES 1 Beasley MB Franks TJ Galvin JR Gochuico B Acute fibrinous and organizing pneumonia: A histological pattern of lung injury and possible variant of diffuse alveolar damage Arch pathol Lab Med 2002 126 1064 70 12204055 2 Damas C Morais A Moura CS Marques A Acute fibrinous and organizing pneumonia Rev Port Pneumol 2006 12 615 20 17117329 3 Prahalad S Bohnsack JF Maloney CG Leslie KO Fetal acute fibrinous and organizing pneumonia in a child with juvenile dermatomyosits J Pediatr 2005 146 289 92 15689928 4 Kobayashi H Sugimoto C Kanoh S Motoyoshi K Aida S Acute Fibrinous and organizing pneumonia: Initial presentation as a solitary nodule J Thorac Imaging 2005 20 291 3 16282908 5 Yokogawa N Alcid DV Acute fibrinous and organizing pneumonia as a rare presentation of abacavir hypersensitivity reaction AIDS 2007 21 2116 7 17885309 6 Lee SM Park JJ Sung SH Kim Y Lee KE Mun YC Acute fibrinous and organizing pneumonia following hemaotopoietic stem cell transplantation Korean J Intern Med 2009 24 156 9 19543497 7 Heo JY Song JY Noh JY Yong HS Cheong HJ Kim WJ Acute fibrinous and organizing pneumonia in a patient with HIV infection and Pneumocysis Jiroveci Pneumonia Respirology 2010 15 1259 16 20920123 8 Hariri LP Unizony S Stone J Mino-Kenudson M Sharma A Matsubara O Acute fibrinous and organizing pneumonia in systemic lupus erythematosus: A case report and review of the literature Pathol Int 2010 60 755 9 20946526 9 Bhatti S Hakeem A Torrealba J McMahon JP Meyer KC Severe acute fibrinous and organizing pneumonia (AFOP) causing ventilator failure: Successful treatment with mycophenolate mofetil and corticosteroids Respir Med 2009 103 1764 71 19666216 10 Vasu TS Cavallazzi R Hirani A Marik PE A 64-year –old male with fever and persistent lung infiltrate Respir Care 2009 54 1263 5 19712502 11 Balduin R Giacometti C Saccarola L Marulli G Rea F Bartoli M Acute fibrinous and oraganizing pneumonia in a patient with collagen vascular disease “stigma” Sarcoidosis Vasc Diffuse Lung Dis 2007 24 78 80 18069424 12 Tzouvelekis A Koutsopoulos A Oikonomou A Acute fibrinous and organizing pneumonia: a case report and review of the literature J Med Case Reports 2009 3 74 13 Ronald C Sucaibi SDO Ramsey R Acute lymphoblastic leukemia presenting with an acute fibrinous and organizing pneumonia J Respir Dis 2007 28 33 5 14 Mittal V Kulshrestha R Arya A Bajaj P Acute fibrinous and organizing pneumonia presenting as complete lung consolidation Singapore Med J 2011 52 88 90 15 Canessa PA Pratticò L Sivori M Magistrelli P Fedeli F Cavazza A Acute fibrinous and organizing pneumonia in Whipple disease Monaldi Arch Chest Dis 2008 69 186 8 19350842 16 Hwang DM Chamberlain DW Poutanen SM Low DE Asa SL Butany J Pulmonary pathology of severe acute respiratory syndrome in Toronto Mod Pathol 2005 18 1 10 15272286