SESSION TITLE: Interstitial Lung Disease Case Report Posters
SESSION TYPE: Affiliate Case Report Poster
PRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PM
INTRODUCTION: Pulmonary ossification (PO) is a rare disorder of heterotrophic bone formation within the lung that can cause interstitial lung disease. We report a case of PO diagnosed by open lung biopsy.
CASE PRESENTATION: A 70-year-old male ex-smoker (20 pk yr) with COPD, bronchiectasis, and undiagnosed interstitial lung disease presented with progressive cough and dyspnea.The patient had occupational exposure to beryllium and fiberglass as a mechanic.PFT’s showed a mild obstructive ventilatory defect that was unchanged over several years, but his TLC (7.4-->6.7 L), and diffusion capacity declined (61-->47%) more than anticipated.His 6 min walk test was 450 meters with mild desaturation.Previous workup included negative rheumatologic, hypersensitivity pneumonitis panel, and infectious studies.Chest CT scans showed moderate emphysema with bilateral reticulonodular interstitial infiltrates, and pleural short lines predominantly in the lower lobes that progressed over five years.Patient underwent two bronchoscopies with transbronchial biopsies, which revealed tracheopathia osteoplastica, minimal interstitial fibrosis, and no definitive diagnosis.Wedge biopsy of the RML and RLL showed end stage lung disease with emphysema, extensive racemose dendriform ossification, but no granulomas.Review of his pathology failed to identify any background interstitial lung disease.
DISCUSSION: The latest classification of idiopathic interstitial pneumonias does not include pulmonary ossification disorders among its causes (1). However, PO has been recognized as a cause of fibrotic lung disease (2).The pathogenesis of PO may be related to cell injury, alkaline environment, presence of collagen and cytokines, or metallic deposition (3).There are two types of pulmonary ossification: dendriform, and nodular which is associated with cardiac disease.Dendriform may be idiopathic or related to lung injury.In our case the PO may be due to the patient’s past occupational exposures.There are no diagnostic laboratory values.Restriction can be seen with extensive disease.Most cases of PO are diagnosed on autopsy, but diagnosis can be made by open lung or transbronchial biopsy. In general, patients show a slow decline in pulmonary function.Therapeutic options are limited and include bisphosphonates.
CONCLUSIONS: Pulmonary ossification is a rare cause of interstitial lung disease.
Reference #1: ATS ERS: Update on IIP guidelines, AJRCCM 2013;188:733-748
Reference #2: Chan, E et al. AJRCCM, 2002;165:1654-1669
Reference #3: Tatjana, P et al. Curr Opin in Pulm Med, 2008;14:488-492
DISCLOSURE: The following authors have nothing to disclose: Eugene Yeh, Stephen Liu, Guy Soo Hoo
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