Immature teratoma arising from an intra-abdominal undescended testis in a child: a case report

Introduction and importance: Pediatric immature teratoma arising from an undescended intra-abdominal testis is rarely reported in the literature. Cryptorchidism is a recognized risk factor for testicular germ cell tumors; however, seminoma is the most commonly reported malignancy. Case presentation: A 4-year-old boy from northwestern Ethiopia presented with progressive abdominal distension and a non-palpable right testis since birth. Physical examination revealed a large, firm lower abdominal mass and an absent right testis. Laboratory investigations demonstrated an alpha-fetoprotein level of 96 ng/mL and a β-human chorionic gonadotropin level of 18.8mIU/mL. Contrast-enhanced computed tomography showed a large heterogeneous cystic-solid abdominopelvic mass with septations, fat attenuation, and calcifications, causing displacement of adjacent viscera and left hydronephrosis. Exploratory laparotomy revealed a huge encapsulated retroperitoneal tumor arising from a right intra-abdominal undescended testis; complete excision was performed with uneventful recovery, and the patient remained disease-free during 3 years of follow-up. Histopathologic examination showed epithelial, mesenchymal, and neuroglial components with focal immature neuroectodermal tissue, consistent with grade 1 immature teratoma (pT1N0Mx). Clinical discussion: Immature teratoma arising in an undescended intra-abdominal testis is an uncommon condition in pediatric patients. Large intra-abdominal masses associated with cryptorchidism should raise suspicion for germ cell tumors. Radiological imaging assists in characterization and operative planning; however, definitive diagnosis depends on histopathological evaluation. Complete surgical excision remains the cornerstone of management and is associated with an excellent prognosis in low-grade tumors. Conclusion: This case highlights the importance of early evaluation and treatment of cryptorchidism to reduce the risk of malignant transformation. Germ cell tumors should be considered in children presenting with abdominal masses and non-palpable testes.