A case of splenogonadal fusion in the left testis.

Splenic tissue outside the normal anatomical site can be collectively referred to as ectopic spleen. Clinically, the commonest causes of ectopic spleen include accessory spleen, splenic tissue implantation, and splenogonadal fusion (SGF). Accessory spleen is mostly caused by congenital dysplasia, is mostly located near the spleen, and may be supplied by the splenic artery. Splenic implantation is mostly caused by autologous spleen tissue transplantation caused by trauma or surgery. SGF is the abnormal fusion of the spleen with the gonad or with the mesonephric derivatives. As a rare developmental malformation, it is difficult to make a correct diagnosis preoperatively, and easily misdiagnosed as a testicular tumor cause lifelong harm to patients. An 18-year-old male student who developed left testicular pain without obvious cause that radiated to the perineum 4 months prior to presentation. He was diagnosed with cryptorchidism 12 years ago and underwent orchiopexy without intraoperative frozen section examination. An ultrasound was performed, identifying hypoechoic nodules in the left testis, suggestive of seminoma. During surgery, the testicular tumor revealed a dark red tissue and the diagnosis of a pathological ectopic splenic tissue was made. Because the clinical manifestations of SGF are not specific, misdiagnosis and unnecessary orchiectomy may occur. If a complete preoperative examination which includes biopsy or intraoperative frozen section is performed, unnecessary orchiectomy can be effectively avoided and bilateral fertility can be preserved.