ACUTE MYELOID LEUKEMIA AND MYELOID SARCOMA: AN UNUSUAL CAUSE OF RESPIRATORY FAILURE AND CARDIAC TAMPONADE

TOPIC: Disorders of the Mediastinum TYPE: Fellow Case Reports INTRODUCTION: Mediastinal masses represent a diverse pathology with use anatomic location narrowing differential diagnoses. Common causes anterior mediastinal include thymomas, teratomas and lymphomas. We present case in which mass diagnosed as myeloid sarcoma from Acute Myeloid Leukemia (AML) caused respiratory failure cardiac tamponade. CASE PRESENTATION: A 21-year-old African American male presented to emergency department complaints unintentional weight loss, night sweats, orthopnea. He also noted odynophagia facial swelling. endorsed occasional marijuana use. Physical exam was remarkable for increased work breathing, tachypnea, oxygen saturations 99% on room air, muffled voice cervical lymphadenopathy. Laboratory testing significant Leukocytes 8.3 thou/mcL, Blasts 8%, Hematocrit 17.6%, lactated dehydrogenase > 4000 U/L, Uric Acid 7.9 mg/dL. Chest radiograph revealed cardiomegaly, multifocal airspace disease lobular contour right suprahilar area concerning mass. Computed Tomography thorax showed bulky lymphadenopathy compatible lymphoma ground glass opacities. Patient underwent non-emergent intubation due impending airway compromise. Transthoracic Echocardiogram small pericardial effusion extrinsic compression ventricle associated an extrapericardial Lymph node biopsy consistent lymphoma. However, flow cytometry demonstrated acute leukemia, confirmed bone marrow biopsy. The sarcoma. patient started chemotherapy; however, leukemia did not respond therapy, died multiorgan failure. DISCUSSION: Sarcoma is distinct presentation AML extramedullary consisting blasts. Sarcomas can relapse previously myeloproliferative neoplasms (MPN); coexist MPNs. Usual sites bone, periosteum, lymph nodes soft tissue; involvement rare, accounting 4% tumors mistaken CONCLUSIONS: patients history MPNs or hematologic abnormalities should prompt concern REFERENCE #1: Arber DA, Orazi A, Hasserjian R, Thiele J, Borowitz MJ, Le Beau MM, Bloomfield CD, Cazzola M, Vardiman JW. 2016 revision World Health Organization classification leukemia. Blood. May 19;127(20):2391-405. doi: 10.1182/blood-2016-03-643544. Epub Apr 11. PMID: 27069254. #2: Paydas S, Zorludemir Ergin M. Granulocytic sarcoma: 32 cases review literature. Leuk Lymphoma. 2006 Dec;47 (12):2527-41. 10.1080/10428190600967196. 17169797. #3: Carter BW, Marom EM, Detterbeck FC. Approaching mass: guide clinicians. J Thorac Oncol. 2014 Sep;9(9 Suppl 2):S102-9. 10.1097/JTO.0000000000000294. 25396306. DISCLOSURES: No relevant relationships by Lamia Aljundi, source=Web Response Matthew Haltom, Cristobal Risquez,