SESSION TITLE: Medical Student/Resident Pulmonary Vascular Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Pulmonary vein thrombosis (PVT) is an uncommon and often undiagnosed condition with symptoms ranging from completely asymptomatic to life threatening systemic arterial embolization. Complications include pulmonary edema, infarction and Cor Pulmonale secondary to increased pulmonary venous pressures leading to pulmonary hypertension. Malignancy is a known risk factor for PVT and is theorized that it results as a possible direct extension of tumor in vein, direct compression or epithelial damage from tumor invasion. CASE PRESENTATION: We present a case of a 67-year-old male with history significant for primary pulmonary diffuse large B cell lymphoma (DLBCL) who presented to the hospital after CTA revealed a pulmonary vein mass in the pulmonary vein extending into the atrium in addition to the newly diagnosed 12 cm tumor in the right hemithorax. Echocardiogram did not reveal any decrease in systolic function or hypertrophy of ventricles. The patient was clinically asymptomatic save for some nonspecific weakness and malaise. Patient was started on Heparin and discharged on 3 months of oral anticoagulation which will most likely be lifelong considering his malignancy. DISCUSSION: This case demonstrates pulmonary vein thrombosis in the setting of DLBCL. PVT can be easily be missed due to nonspecific symptoms. There is no gold standard for diagnosis, however CTA is preferred method, there may not be any findings on Echo is it was in our case. There is currently no consensus on duration of anticoagulation and role of thrombectomy. CONCLUSIONS: A high degree of suspicion is required for diagnosis especially in patients with predisposing risk factors like malignancy, post lung surgery or atrial fibrillation. Once diagnosis is made, prompt treatment is necessary to avoid lung infarction and possible lobe resection. Reference #1: Olutola Akiode; Gagan Prakash, Fed Pract. 2014 December;31(12):26-28, Pulmonary Vein Thrombosis Associated With Metastatic Carcinoma, MDEDGE DISCLOSURES: No relevant relationships by Ravinder Bhanot, source=Web Response No relevant relationships by Mohamed Mohamed, source=Web Response No relevant relationships by Jared Steinberger, source=Web Response