Testicular tumors in children are rare accounting for 1–2% of all pediatric solid tumors with an incidence of 0.5–2.0/100,000 children and adolescents [2, 5, 6]. About 10% of testicular tumors are associated with UDT, and association between UDT and malignancy has been well established . Earlier risk of developing testicular tumor in UDT had been considered to be 30–50 times greater than in the general population being highest with IAT intraabdominal testis , but recently, it has been estimated as 3–8 times higher than in the general population and most commonly seen in intraabdominal testis . Testicular tumors in UDT usually occur at the same age as testicular tumors in normally descended testes, i.e., 20–40 years [2,3,4]. However, testicular tumors arising in UDT are rare in prepubertal children, particularly in intraabdominal testis [2, 3].
Since its first report in 1941 to 2015, 38 cases of intraabdominal testicular tumors in prepubertal children had been reported [2, 3]. Most of the intraabdominal testicular tumors in prepubertal children were teratomas in contrast to intraabdominal testicular tumors in adolescents and adults in whom seminoma is the most common testicular tumors [2, 3]. Malignant tumors in intraabdominal testis in prepubertal children are very unusual. We have found only four cases of intraabdominal testicular YST in prepubertal children. YSTs produce alpha-fetoprotein in very high concentrations and can be diagnosed by measuring raised serum alpha-fetoprotein levels . However, our case is the first case of intraabdominal testicular YST because despite being YST, preoperative serum alpha-fetoprotein was normal. This could be explained by replacement of majority of testicular tissue by necrosis and hemorrhage as seen in HPE due to the presence of torsion in our case. Torsion might have resulted in death of most of the right intraabdominal testicular YST tissue due to occlusion of blood supply to right testis and resulted in normal preoperative serum alpha-fetoprotein.
Testicular tumors in intraabdominal testis in prepubertal children can present either as asymptomatic testicular mass detected during evaluation of nonpalpable UDT or with symptoms like abdominal pain or abdominal lump associated with mid or severe pain, nausea, vomiting or low-grade fever due to torsion, hemorrhage, or rupture of intraabdominal testicular tumors [2, 3, 9, 10]. Imaging studies such as ultrasound or CECT abdomen can be useful adjuncts in making diagnosis of intraabdominal testicular tumors in both asymptomatic and symptomatic cases with nonpalpable UDT [2, 3, 9]. Role of laparoscopy has also been described in both diagnosis and treatment for intraabdominal testicular tumors . Torsion had been reported to occur in about 60% of cases of intraabdominal testicular tumors in prepubertal children [2, 3, 10]; similarly, our case too had torsion at the time of laparotomy, resulting in necrosis and hemosiderin deposition in HPE. Therefore, torsion testis forms an important differential diagnosis of intraabdominal testicular tumors; and exact diagnosis can be made after histopathologic examination and immunohistochemistry.
Majority of intraabdominal testicular tumors in prepubertal children are clinically stage I tumors which can be managed with radical orchiectomy and surveillance with frequent measurement of tumor markers and thoracic and abdominal imaging similar to those in descended testes in prepubertal children [2, 5, 6]. Therefore, we have also performed only right radical orchiectomy and frequent monitoring with estimation of tumor markers and imaging studies and noticed favorable outcome with normal serum alpha-fetoprotein and no recurrence or distant metastasis of tumor at 12-month follow-up after discharge.