Venous Thromboembolism and Thymic Hyperplasia in the Setting of Silent Graves' Disease

Venous thromboembolism is a common, yet serious life-threatening condition that has many well-recognized associations which include but are not limited to pregnancy, polycythemia, trauma, immobility, and malignancy. The pathophysiology behind the pro-coagulant effects of hyperthyroidism has been well established; however, there are no current guidelines regarding deep venous thrombosis (DVT) surveillance in patients with hyperthyroidism. In this report, we discuss the case of a 36-year-old female with no significant past medical history (PMH) with the exception of a 15 pack-year smoking history, who presented to us with an extensive, rapidly-progressing lower extremity DVT. Despite aggressive treatment measures, she developed a pulmonary embolus in the hospital. During her stay, she was diagnosed with Graves' disease by hormone profile and thyroid-stimulating hormone receptor (TSH-R) antibody positivity. Additionally, an incidental thymic mass, likely thymic hyperplasia, was found on imaging and presumed to be associated with Graves' disease. This case study reports a difficult-to-treat venous thromboembolism in the setting of Graves' disease along with a review of current literature and pathophysiology on the subject.