Upper extremity deep vein thrombosis is an extremely important clinical entity with potential for considerable morbidity and mortality. A 64-year-old woman was brought to the emergency department with complaints of left upper limb and neck swelling for 4 days. Ultrasonography of the neck showed thrombosis of the left internal jugular and other surrounding veins associated with local lymphadenopathy. Computed tomography (CT) of the neck also showed a hypodense 0.6 cm × 0.8 cm × 1.2 cm lesion in the right middle lobe bronchus, causing complete occlusion and collapse of the right middle lobe of the lung. Fine-needle aspiration cytology and a lymph node biopsy showed nongranulomatous lymphadenitis. The patient was started on fondaparinux 10 mg subcutaneously once daily. She was discharged on oral anticoagulants for 6 months. Repeat CT scan after 6 months showed dissolution of the lesion and reexpansion of the right lung.