Prepubertal testicular tumors represent 1% of solid pediatric tumors [6]. The epidemiology varies from that of adult testicular tumors: yolk sac tumors and teratoma, both nonseminomatous germ cell tumors, comprise 85% of testicular tumours in boys younger than 12 years, while representing 1% in adults [7]. In neonates younger than 30 days, 22 cases, or 6.5% of all prepubertal testicular tumors, have been reported in the Prepupertal Testis Tumour Registry with the following distribution: 6 (27%) yolk sac tumors, 6 gonadal stromal tumors, 6 JGCTs (sex-cord stromal tumors), 2 (9%) gonadoblastomas (mixed germ cell and stromal tumors), 1 (5%) teratoma, and 1 hamartoma [8]. Of these tumors, 7 (31%) presented at birth as a testicular mass.
In this case, knowing an orchiectomy was the most likely outcome based on sonographic findings, the surgeon opted empirically for an inguinal approach. To our knowledge, only one other similar case of a testicular tumor (teratoma) presenting as a prenatal testicular torsion in a baby with descended testes has been reported [9]. An inguinal approach is optimal if the surgeon proceeds to surgery for a prenatal testicular torsion, given the chance of an underlying testicular tumor.
Unfortunately, we could not achieve a histopathological diagnosis as extensive testicular necrosis rendered analysis impossible. However, the favorable evolution of the patient documented over 15 years is highly suggestive of a benign testicular mass.
Heterogenous echoes, occasional calcifications, and multiple intratesticular cysts are frequent sonography findings in teratoma but have also been associated with testicular cysts, JGCT, and cystic dysplasia of the rete testis [10]. Moreover, after torsion, cystic degeneration with formation of cystic spaces filled by necrotic debris and haemorrhagic infarction can produce similar images [10]. Mature teratomas have a median age of presentation of 13 months, are benign tumors and do not express AFP [10]. No teratoma, in the absence of immature components, has been documented to cause metastasis [11]. Thus, mature teratoma may be treated with partial orchiectomy [12]. Elevated AFP is suggestive of yolk sac tumors, which are the most common malignant prepubertal testicular tumors, generally presenting at 16 months [10]. Yolk sac tumors require inguinal orchiectomy, close follow-up, and may be considered for platinum-based chemotherapy according to the stage [13]. Seven-year survival of children younger than 2 years old presenting with stage I yolk sac tumor is 90% [13]. In children younger than 1 year, AFP is of lesser diagnostic value in distinguishing mature teratomas from yolk sac tumor since there is physiological AFP production in the liver and gastro-intestinal tract, as well as by the fetal yolk sac [7]. Finally, JGCTs are benign sex-cord stromal tumors. Most JGCTs (90%) are diagnosed in infants < 6 months and produce cystic lesions [10, 14]. The only stromal tumors that have been documented to cause metastasis in neonates are undifferentiated stromal tumors. These rare tumors require close follow-up, radical inguinal orchiectomy, and may benefit from retroperitoneal lymph node dissection, radiation, or chemotherapy [15].