Yolk sac tumor in intraabdominal undescended testis in a child with normal serum alpha-fetoprotein: a rare case report

Abstract
Background
Intraabdominal testicular tumors are rare in prepubertal children, and most of the cases reported are intraabdominal testicular teratoma. The present study reports the first case of intraabdominal testicular yolk sac tumor (YST) with normal preoperative serum alpha-fetoprotein levels and diagnosis confirmed on histopathology and immunohistochemistry.


Case Presentation
A 2-year-old boy presented with bilateral nonpalpable undescended testes (UDT) and abdominal mass. Preoperative serum alpha-fetoprotein was normal. Contrast-enhanced computed tomography (CECT) scan of whole abdomen revealed a heterogeneous mildly enhancing space-occupying lesion in midline and left side of pelvis, left intraabdominal testis and nonvisualization of right testis. During surgery, the mass was found to involve right testis with one turn of torsion of its pedicle. Derotation of testis was performed, and right radical orchiectomy was performed. Left orchiopexy was also performed at the same time. Histopathology and immunohistochemistry confirmed diagnosis of intraabdominal testicular YST. There was no recurrence or distant metastasis at 12-month follow-up after surgery.


Conclusion
In a case of nonpalpable UDT and abdominal mass/pain, one should always consider possibility of intraabdominal testicular tumor and should investigate the case with serum tumor markers and ultrasound/CECT abdomen. Further, histology of tumor helps in guiding treatment of condition.