A RARE CASE OF RADIATION-PRIMED CRYPTOGENIC ORGANIZING PNEUMONIA

Abstract

TOPIC: Pulmonary Manifestations of Systemic Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Cryptogenic organizing pneumonia (COP) has rarely been associated with radiotherapy for breast cancer since the advent of planned irradiation field therapy. Here we present a case of a woman diagnosed with radiation-primed COP, diagnosed on lung biopsy. CASE PRESENTATION: A 78-year-old female with a medical history of asthma and three year old history of invasive ductal carcinoma of the right breast post lumpectomy, radiotherapy and adjuvant Taxol and Herceptin chemotherapy presented to the hospital with symptoms of progressive dyspnea. CT Chest at the time of admission revealed patchy areas of ground-glass and peripheral nodular consolidation with cavitation superimposed on postradiation fibrosis. She was diagnosed with pneumonia and discharged on a 5 day course of Amoxicillin-Clavulanic Acid.She continued to have persistent dyspnea, dry cough and was retreated with a 7 day course of Levofloxican. She symptoms persisted and a repeat CT Chest performed a month later demonstrated persistent pulmonary opacities concerning for cryptogenic organizing pneumonia and she underwent a CT-guided biopsy. Pathology revealed acute lung injury consistent with organizing pneumonia and cultures were negative for bacteria, fungi or acid-fast bacilli. She was treated with 1 mg/kg of prednisone daily, adjusted body weight, for a total of 3 months and experienced complete resolution of symptoms. DISCUSSION: Radiotherapy is the core treatment of breast cancer with planned field irradiation allows for minimal risk of side effects e.g. pneumonia and fibrosis. Pneumonia typically presents 4 to 12 weeks after radiotherapy; it's characterized by dyspnea, dry cough and alveolar opacities restricted to the treatment port [1]. In rare cases, bilateral lymphocytic alveolitis can develop, in spite of a limited radiation treatment area and it's radiological and histological pattern emulates cryptogenic organizing pneumonia (COP) [2]. Corticosteroid treatment in COP often results in rapid correction of both clinical symptoms and radiological signs; the precise dose and duration of treatment has not yet been defined [1].In our case, the patient presented with the typical signs of pneumonia and failed multiple rounds of treatment with antibiotics. The correct diagnosis was only established months later, after her symptoms persisted and a pathological tissue sample and negative cultures enabled a conclusive diagnosis of radiation-primed COP. Her clinical response to systemic corticosteroid provided further confirmation of her diagnosis. CONCLUSIONS: A high index of suspicion is required in order to diagnose radiation-primed cryptogenic organizing pneumonia. Clinicians must be aware of its chronic and persistent presentation if left untreated, as early diagnosis will prevent significant physical and psychological morbidity. REFERENCE #1: Bradley B, Branley HM, Egan JJ, et al. Interstitial lung disease guideline: the British Thoracic Society in collaboration with the Thoracic Society of Australia and New Zealand and the Irish Thoracic Society [published correction appears in Thorax. 2008 Nov;63(11):1029. multiple author names added]. Thorax. 2008;63 Suppl 5:v1-v58. doi:10.1136/thx.2008.101691 REFERENCE #2: Roberts CM, Foulcher E, Zaunders JJ, Bryant DH, Freund J, Cairns D, Penny R, Morgan GW, Breit SN. Radiation pneumonitis: a possible lymphocyte-mediated hypersensitivity reaction. Ann Intern Med. 1993;118:696–700. DISCLOSURES: No relevant relationships by Suhayb Ranjha, source=Web Response