SESSION TITLE: Medical Student/Resident Pulmonary Manifestations of Systemic Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Intravascular large B cell lymphoma (IVLBCL) is a rare form of Non-Hodgkin’s Lymphoma (NHL) that, in most cases, is disseminated at time of diagnosis with majority of manifestations in the central nervous system, cutaneous lesions, or hematologic syndromes. Lung involvement, though not uncommon, is most likely found during autopsy as early diagnosis of IVLBCL has proven to be difficult. CASE PRESENTATION: A 67 year-old male with no known medical history presented with progressive, subacute dyspnea and fatigue. On exam he was hypoxic with fine rales to auscultation and decreased air entry bibasally. Labs revealed moderate anemia, lactic acidosis, acute renal impairment, and transaminitis. CT chest non-contrast showed diffuse ground glass appearance with no acute consolidations or effusions. Peripheral blood smear showed no schistocytes; serum protein electrophoresis and erythrocyte sedimentation rate were unremarkable; ANCA and HIV were negative. Bone marrow biopsy was performed revealing hypercellularity with no evidence of malignancy; bronchoscopy was non-diagnostic. PET scan revealed areas of tracer uptake in the lungs and subsequent VATS with lung biopsy showed nonspecific pneumonitis: hilar membranes, reactive pneumocytes and collapsed vessels, making visualization of intravascular cell invasion difficult. Findings seemed consistent with interstitial lung disease, however, due to unknown origin of lung disease and acute onset of symptoms, the sample was sent for further pathologic review. Subsequent staining of cells revealed positive MUM-1, BCL-6 & BCL-2, CD45, CD20, PAX5, c-myc (20%) and Ki67. CD34 was negative. The final diagnosis was IVLBCL. DISCUSSION: IVLBCL is rare and characterized by the presence of tumor cells within blood vessels. The disease is highly malignant and carries a poor prognosis, as the majority of patients present late in disease course. The lung as a primary source of IVLBCL is a very rare occurrence with only a few cases reported. Although in this case diffuse ground glass appearance was present on chest CT, there was no explanation for pathology findings of interstitial lung disease, which necessitated further testing ultimately revealing a diagnosis. It is apparent that a confirmatory diagnosis of IVLBCL is quite difficult and involves intensive pathologic review. CONCLUSIONS: It is important for physicians to consider a diagnosis of IVLBCL, albeit rare, in patients who present with respiratory symptoms and no apparent cause. Ruling out other possible causes of clinical presentation, as well as adequate pathology samples, are paramount. Reference #1: 1.Yamashita, Hiroyuki, et al. “Intravascular Large B-Cell Lymphoma with Diffuse FDG Uptake in the Lung by 18FDG-PET/CT without Chest CT Findings.” Annals of Nuclear Medicine, vol 26, 27 Apr. 2012, pp. 515-521 Reference #2: 2.M. Fiegl, R. Greil, C. Pechlaner, J. Krugmann, S. Dirnhofer, Intravascular large B-cell lymphoma with a fulminant clinical course: a case report with definite diagnosis post mortem, Annals of Oncology, Volume 13, Issue 9, 2002 September, pp.1503–1506 Reference #3: 3.Ponzoni, Maurilio, et al. “Definition, Diagnosis, and Management of Intravascular Large B-Cell Lymphoma: Proposals and Perspectives From an International Consensus Meeting.” Journal of Clinical Oncology, vol 25, no. 21, 20 July 2007, pp. 3168-3173 DISCLOSURES: No relevant relationships by Lewis Attas, source=Admin input No relevant relationships by Alyssa Foster, source=Web Response No relevant relationships by Manuel Katz, source=Web Response No relevant relationships by Dan Ran-Castillo, source=Web Response No relevant relationships by Jonathan Shammash, source=Web Response No relevant relationships by Matthew Tavares, source=Web Response