Case Presentation: This is a case of a 28-year-old transgender male on Testosterone for one year, with no past medical or surgical history, no pertinent family history, and current daily smoker, who presented to the emergency room with abdominal pain. The patient had presented to the ED five days earlier for vomiting and was discharged home with suspected gastroenteritis. He then developed left lower quadrant (LLQ) abdominal pain and returned to the ED. Physical exam was significant for a fever (101F), tachycardia (HR 112), and LLQ tenderness. Labs were notable for leukocytosis (WBC 17.6) and polycythemia (Hgb 16.9). A CT scan of the abdomen and pelvis showed thrombophlebitis of the left ovarian vein. The patient was admitted and started on a Heparin drip. Hematology was consulted and concluded that the patient’s polycythemia and thrombosis were both likely due to his Testosterone use, though it was unclear if the thrombosis was a consequence of polycythemia. Polycythemia resolved without phlebotomy, WBC normalized, and he was discharged home on Xarelto with Hematology follow-up.
Discussion: Estrogen therapy is a well-known risk factor for venous thromboembolism. However, studies evaluating the risk of thrombosis associated with Testosterone therapy have been inconclusive and sample sizes are often small. Several studies have suggested that Testosterone may help precipitate a clot in those with underlying thrombotic risk factors, and therefore addressing any modifiable risk factors, such as smoking cessation in the above patient, should be considered prior to starting therapy. The most common adverse effect of Testosterone use is erythrocytosis, however the association between this phenomenon and thrombotic risk is unclear. Data regarding the use of phlebotomy to mitigate this risk is also limited.
Conclusions: Large, prospective studies evaluating the adverse effects associated with Testosterone use, such as venous thromboembolism, for female-to-male gender transition are lacking. Given the long-term use of this therapy in this population, a detailed discussion regarding the potential risks and benefits should occur with patients considering hormonal therapy, and modification of thrombotic risk factors should be addressed prior to initiation. The transgender population has increased drastically over recent years. In 2016, an estimated 1.4 million adults in the United States identified as transgender, which was double that of the estimate in 2011. These statistics suggest that the use of Testosterone therapy has also increased significantly, necessitating further research into the safety profile of its long-term use.