Introduction The occurrence of primary tumours in the seminal vesicle is rare. The types of tumours that can be found include adenocarcinomas, sarcomas, and mixed tumours. We report a rare MEST in a seminal vesicle in a 53-year-old, which was diagnosed using a multiparametric MRI scan after he had haematospermia. It was successfully treated with robotic-assisted removal.

Methods A 53-year-old male presented with haematospermia, His multiparametric MRI scan showed a 4.2 cm septated cyst on the left seminal vesicle with enhanced soft tissue along the superior aspect, which is suspicious for seminal vesicle malignancy. The patient had a successful robotic-assisted removal of the seminal vesicle that required only one day of admission and without documented complications. The diagnosis of a mixed epithelial stromal tumour of the seminal vesicle was confirmed after microscopy and immunohistochemistry examination.

Results Mixed epithelial-stromal tumours are rare and predominantly benign neoplasms that typically originate from the urogenital tract. In males, it is exceptionally rare and is associated with a history of hormonal therapy, often coupled with managing prostate cancer.

Conclusion MEST tumours are rare and associated with different symptoms that include haematospermia. It is usually diagnosed before surgery with an MRI or CT scan. We report a rare cancer that was successfully treated with robotic-assisted removal of the seminal vesicle.