Rare Diagnosis, Odd Appearance: Atypical Radiologic Presentation of Cryptogenic Organizing Pneumonia

Abstract

SESSION TITLE: ILD Case Report Posters IISESSION TYPE: Case Report PosterPRESENTED ON: Sunday, March 23, 2014 at 01:15 PM - 02:15 PMINTRODUCTION: Cryptogenic organizing pneumonia (COP) is a rare entity that is typically suspected based on a characteristic radiological picture. We report a rare atypical radiological presentation of COP in an immune-suppressed host. CASE PRESENTATION: 86-year-old female, a reformed 30-pack year smoker, was admitted with exertional shortness of breath of 3 weeks duration. Medical history was significant for polymyalgia rheumatica on long term prednisone therapy as well as stage IB adenocarcinoma of the lung s/p left lower lobectomy 18 months prior to presentation. On examination, the patient was noted to be hypoxemic requiring 6lpm of oxygen to maintain saturation above 90%. Rest of the physical examination was unremarkable. Routine blood work was unrevealing. CT chest revealed patchy ground glass opacities (GGO) in the left upper lobe. With unilateral infiltrates of unclear etiology in an immune-suppressed patient with a history of adenocarcinoma of the lung, infections as well as recurrence of malignancy were entertained as the most likely diagnostic considerations. Extensive infectious, autoimmune and cardiac work up was negative. With minimal clinical, biochemical or radiological clues to favor any particular pathological process, bronchoscopy with transbronchial lung biopsies was performed. Histopathology from lung biopsy specimens yielded the diagnosis of organizing pneumonia leading to a final clinico-pathologic diagnosis of COP. The patient was treated with high doses of oral prednisone with marked symptomatic improvement and complete radiologic resolution over the ensuing weeks. DISCUSSION: Organizing pneumonia (OP) is a pathologic entity characterized by the presence of buds of granulation tissue (Masson bodies) within the lumen of small airways and extending into the alveolar ducts and alveoli. When seen in the absence of any obvious etiology, the term COP (previously known as idiopathic BOOP) is used. Epidemiologic data suggest that COP is a rare illness with an incidence of approximately 1/100,000. Included in the ATS/ERS consensus classification of idiopathic interstitial pneumonias, OP is a unique inflammatory disease that is completely reversible despite the development of intra-alveolar fibrosis. As clinical manifestations are non-specific, it is the typical radiologic pattern of bilateral patchy alveolar opacities in sub-pleural distribution that raises suspicion for OP. Although other less common patterns have been described, COP presenting as unilateral GGO is exceedingly rare with only 1 prior description to the best of our knowledge. Tissue diagnosis is frequently warranted and corticosteroid treatment represents the standard therapy in COP. CONCLUSIONS: This case highlights that COP, a well known clinical mimic, can also present with unusual radiological features making diagnosis a challenge.Reference #1: Oymak FS, Demirbas HM, et al. Bronchiolitis obliterans organizing pneumonia. Clinical and roentgenological features in 26 cases. Respiration. 2005;72(3):254-62.Reference #2: Cottin V, Cordier JF. Cryptogenic organizing pneumonia. Semin Respir Crit Care Med. 2012; 33(5):462-75.Reference #3: García Aguilar DJ, Cobos Moreno I, et al. Atypical radiological presentation of a cryptogenic organising pneumonia. Arch Bronconeumol. 2010; 46(9): 496-7. DISCLOSURE: The following authors have nothing to disclose: Tathagat Narula, Neha Narula, Sudhir KrishnanNo Product/Research Disclosure Information.