L. M. is a 2-year-old boy who presented to the pediatric surgery clinic for evaluation of a left testicular mass. The parents denied any complaints or symptoms of pain as well as reported no urinary symptoms, nausea, vomiting, weight loss, fevers, or skin discoloration. His past medical history was notable for repair of a left inguinal hernia at 3 months of age. An ultrasound was obtained demonstrating an echogenic mass from the inguinal canal to the left scrotum, a small hydrocele, and a normal testis. During the physical exam, he was noted to have a firm, nontender left testicular mass (Figures 1 and 2).

Figure 1. View of the testis (bright red) with fibrous band attached.

Figure 2. View of the splenic tissue after being dissected away from the testis.

DIAGNOSIS

Splenogonadal fusion (SGF).

Splenogonadal fusion is a rare, benign disorder first described in 1883 by Bostroem. It is rarely diagnosed preoperatively and more commonly found in men than women (Li, Luan, Ma, & Chen, 2013; Milliken, Cherian, Najmaldin, & Powis, 2007; Zhang, Tong, & Zhang, 2013). Fifty percent of patients are diagnosed by the age of 10, and 70% of cases are diagnosed before the age of 20. It most often occurs on the left side as a firm, nontender mass (Kocher, Tomaszewki, Cronson, Altman, & Kutikov, 2014). It is felt to occur between Weeks 5 and 8 of gestational development when the splenic anlage and gonadal mesoderm are in proximity. As the testis starts to descend at Week 8, it pulls the splenic tissue along with it (Ferron & Arce, 2013; Lin, Lazarowicz, & Allan, 2007; Milliken et al., 2007). There are only about 170 reported cases worldwide.

There are two types of SGF. Continuous SGF is when the spleen and testis remain connected via a fibrous band, splenic tissue, or beaded cord of splenic tissue. This represents about 56% of cases. In discontinuous SGF, there is no connection between the two organs (Kennedy, Barnard, & Speakman, 2006; Milliken et al., 2007). Intraoperatively, this is often described as a hemangiomatous, dark red structure that is encapsulated. Discontinuous lesions can be dissectible from the testis. Continuous lesions present with more complications due to the vascularity of the spleen. If the right testis is viable, it may be safer to remove the left testis with the mass (Kennedy et al., 2006; Milliken et al., 2007). SGF should be considered as a differential diagnosis when evaluating a testicular mass in order to avoid unnecessary orchiectomy. Because it is difficult to detect preoperatively, Ferron and Acre (2013) recommend high-frequency ultrasound, which can demonstrate echogenic patterns similar to ectopic spleen. Continuous lesions may also be detected on CT, MRI, or technetium 99 scan (Ferron & Arce, 2013; Zhang et al., 2013).

There are several associated anomalies with the continuous form of the disease. The most common are cryptochordism in 31% of cases, with 59% of those being bilateral, and left inguinal hernia. Other anomalies include micrognathia, limb malformations, cardiac, anal, bowel obstruction, testicular cancer, and palatal defects. (Ferron & Arce, 2013; Li et al., 2013; Lin et al., 2010; Milliken et al., 2007; Zhang et al., 2013).

CONCLUSION

Intraoperatively, L. M. was found to have a dark structure adhered to the testis and spermatic cord, which was easily dissected, sparing the testis and spermatic cord. Pathology confirmed splenic tissue. He was seen in follow-up clinic and is doing well.

References