SESSION TITLE: Tuesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: Pulmonary hamartomas are the most common benign tumors of the lung, however less than 20% are found in the airway (1). Endobronchial hamartomas present with symptoms of cough, obstructive pneumonia, hemoptysis and exertional dyspnea whereas their intraparenchymal correlates are typically found incidentally (1). Histologically, endobronchial hamartomas are often composed of lipoid, chondromatous and or boney tissue (1). We report a case of a rare osteochondromatous hamartoma causing post-obstructive pneumonia which was successfully resected with rigid bronchoscopy. CASE PRESENTATION: The patient is a 71 year old male never-smoker. He was in his usual state of health when he developed a nonproductive cough, mild dyspnea and fatigue. He received two courses of outpatient antibiotics with interval improvement. Several months later he presented to the emergency department with high fever and fatigue. A CT demonstrated bibasilar opacities and a right lower lobe endobronchial lesion. He was referred to pulmonology. Our general pulmonologist proceeded with flexible bronchoscopy as the lesion was suspected to be a foreign body or tumor. Bronchoscopy revealed a smooth endobronchial lesion which was obstructing roughly 90% of the anterior basilar segment of the right lower lobe. The lesion could not be traversed by the bronchoscope. Attempts at both needle and forceps biopsy were unsuccessful due to the density of the lesion. An interventional pulmonologist subsequently performed rigid bronchoscopy where the 8 millimeter lesion was charred with a yttrium argon garnet (YAG) laser, then resected. There were no complications. Pathology revealed an osteochondromatous hamartoma. The patient’s symptoms improved within 1 week of resection. DISCUSSION: Typically, hamartomas are composed of lipoid and chondroid tissue. As such, few cases of osteochondromatous hamartomas of the lung have been reported (2,3). Sik, et al. reported a similar case of a bony hamartoma in 2012 which they were able to retrieve by flexible bronchoscopy (2). These reporters noted the lesion to hemorrhage to which they partially attributed to the presence of bone marrow elements within the hamartoma. The bleeding was contained with administration of cold saline and epinephrine. CONCLUSIONS: In our patient the use of YAG laser potentially prevented a significant degree of hemorrhage during the procedure. Comparing the case discussed by Sik et al to our case illuminates a branch point in intervention. If the general pulmonologist is suspicious of calcified tissue or bony elements in an endobronchial lesion, perhaps referral to interventional pulmonology for rigid bronchoscopy could decrease both the number of procedures and bleeding complications from similar lesions. Reference #1: 1. Kim, Su-A., et al. “Bronchoscopic Features and Bronchoscopic Intervention for Endobronchial Hamartoma.” Respirology 15, no. 1 (n.d.): 150–54. Reference #2: 2. Kyu Sik, Kim, et al. “A Case of Endobronchial Osteochondromatous Hamartoma Removed Using Flexible Bronchoscopy.” Archivos de Bronconeumología (English Edition) 48, no. 11 (November 2012): 427–28. Reference #3: 3. Oishi, Hisashi, Toshiharu Tabata, Yoshinori Okada, Mareyuki Endo, Satoshi Suzuki, Yuji Matsumura, and Takashi Kondo. “Rapidly Growing Endobronchial Hamartoma With Bone Marrow Tissue.” The Annals of Thoracic Surgery 81, no. 6 (June 1, 2006): 2287–89. DISCLOSURES: No relevant relationships by Graham Atkins, source=Web Response No relevant relationships by Farhad Mazdisnian, source=Web Response No relevant relationships by John Nuschke, source=Web Response No relevant relationships by David Zielke, source=Web Response