LAUSR

BACKGROUND Primary seminal vesicle adenocarcinoma is a rare malignancy that is difficult to diagnose. CASE SUMMARY A 54-year-old man with an 18-year history of a seminal vesicle cyst presented with worsening hematospermia that had persisted for one month. Dynamic contrast-enhanced computed tomography and pelvic magnetic resonance imaging indicated a mass with a cystic-solid component. Robot-assisted seminal vesicle tumor resection was performed, and primary seminal vesicle adenocarcinoma was confirmed pathologically. The patient received pelvic radiotherapy for six weeks, and to date, no evidence of recurrence has been found. CONCLUSION Seminal vesicle cysts should be monitored long-term. Seminal vesicle adenocarcinoma presents with non-specific symptoms and can be diagnosed by immunohistochemistry.