Abstract
BACKGROUND: Ewing's sarcoma (ES) within the genitourinary tract are relatively unheard of and those within the external male genitalia are even rarer. To our knowledge, this is the first known case of primary ES within the paratesticular region in an adult. CASE PRESENTATION: We present a case of a 24-year-old man with a right sided testicular mass on examination that was initially characterized as an adenomatoid tumor on ultrasound. After the patient was lost to follow up over the course of 9 months, the testicular mass grew significantly and was excised with pathology revealing primary paratesticular Ewing's sarcoma. This rare case emphasizes the importance of elucidating between the broad differentials of paratesticular masses, including the rare presentation of primary ES and adds a review of the literature of ES in the external male genitalia. CONCLUSIONS: Rare differentials such as this case should be considered in patients with paratesticular masses. Further diagnostic and management algorithms for extraosseous Ewing Sarcoma, particularly in the adult population, are warranted.