Testicular germ cell tumors (GCT) have a bimodal distribution with a peak in infancy and a second, substantially larger, peak in adolescence and young adulthood.1 Testicular GCT in prepubertal children is a rare entity, representing approximately 1% of pediatric solid tumors. This corresponds to an incidence of 0.5-2 per 100,000 children2; or 1.6 cases per million person-years.3 While, testicular GCT represents only 0.5% of all malignancies in children <15 years of age, testicular GCT is the most common cancer in males 15-19 years old and is responsible for the most life-years lost of any non-prepubertal pediatric cancer.3,4 Importantly, prepubertal (Type 1) and post-pubertal (Type II) testis tumors differ substantially in incidence, histology and outcome

Classically, testicular tumors in prepubertal pediatric patients were approached in the same fashion as adult testicular masses. However, over the past 20 years, it has been discovered that molecular and histological differences exist between testicular masses in adults and children 5, with puberty being the important dividing line. Early investigation into the rate of malignancy specific to children was conducted through the Prepubertal Testis Tumor Registry and suggested that malignant yolk sac tumor (YST) made up the largest proportion of intra-testicular masses.6 In contrast to this, based on single institution studies and concern for bias by disproportionate registration of malignant masses, a multicenter review of testicular masses was conducted in boys under 12 years of age. This revealed that 48% of the testis masses were actually teratoma and only 15% were YST. Therefore, overall, 74% of prepubertal testis tumors held benign pathology in the study.7 With histologic subtypes of testicular masses favoring benign pathology in prepubertal versus older patients, treatment paradigms for prepubertal patients now largely favor testis-sparing surgery (TSS) in appropriate patients, contrary to classic treatment with radical orchiectomy (RO). In post-pubertal patients, the standard of care continues to be RO in most cases, with some notable exceptions discussed later.

The classic initial treatment for all testicular tumors is inguinal radical orchiectomy (RO). Because of the high rate of benign testis tumors in the prepubertal population and the reliable accuracy of intraoperative frozen section,8,9 partial orchiectomy (PO) has become a safe and viable option for selected patients with normal serum tumor markers. For suspected post pubertal GCT, inguinal RO with high ligation of the spermatic cord is the standard of care with a few exceptions. An additional special note is the use of PO for bilateral tumors or for tumors arising in a solitary testicle. While this chapter will not focus on this very unique clinical scenario, it is a strong recommendation to discuss with an expert in the field when faced with this situation.

For both a RO and PO, the testis is approached via an inguinal incision; thus, avoiding violation of the scrotum, which has different lymphatic drainage from the testis’ well defined pattern of metastatic spread to the retroperitoneum. For testis sparing surgery, the spermatic cord is clamped atraumatically and excisional biopsy, guided by intraoperative ultrasound, of the entire mass is sent for frozen-section analysis.10 It is important to take care not to violate the tumor at this step. If benign pathology is identified, the testicular defect is repaired, and testis returned to the scrotum. Alternatively, if a germ cell malignancy is found, an inguinal RO is completed. With PO, full tumor excision is mandatory as inadequate resection has led to recurrent tumor. Infants with physiologically elevated AFP in the first year of life can still be considered for PO because of the high reliability of frozen section to identify malignant pathology.8,9 Due to the higher risk of malignant and more aggressive behavior in post-pubertal patients, unilateral tumors should routinely undergo inguinal RO; although there has been recent interest in exploring testis sparing surgery in selected adolescent patients with small tumors (<2cm) and normal pre-operative serum tumor markers.11

For staging purposes, prepubertal tumors are defined utilizing The Children's Oncology Group's (COG) staging system. Because of the histological and biological similarities with adults, adult staging systems are used in the post pubertal adolescent and young adult patients: the American Joint Committee on Cancer (AJCC) Tumor-Node-Metastasis-Serum Marker (TNMS) Staging and Group Staging. The International Germ Cell Cancer Consensus Group (IGCCCG) defines risk status for these post pubertal patients with metastatic disease. See Table 1, Table 2, Table 3 for details.

Table 4

As the subsequent portions of this disease section will explain, there are two main points of emphasis in the surgical care of children and adolescents with testicular GCTs. The first is complete surgical resection of the primary tumor. For those patients with malignant GCT this is an inguinal RO with high control of the spermatic cord and no scrotal violation. In pre-pubertal patients with normal (age-appropriate), preoperative serum tumor markers, this would be a complete resection with testis sparing surgery utilizing intraoperative frozen section to ensure a non-malignant GCT histology. The second main point of emphasis for surgical resection in patients with malignant GCTs is complete resection of all residual masses >1cm that remain after chemotherapy once the STMs are normalized. For the retroperitoneum, by far the most common site of spread for testicular GCTs, this involves a formal, anatomic template, retroperitoneal lymph node dissection. Extra-peritoneal sites of residual disease should be surgically resected as well when feasible, either at the same surgical setting as RPLND or as a separate procedure. Adherence to these key surgical oncologic principles are well-demonstrated to correlate with optimal rates of cure.

During radical orchiectomy, surgery must be approached via an inguinal incision, delivering the testis and mass without tumor spillage.

A testis-sparing approach (partial orchiectomy) is the standard of care for pre-pubertal patients with physiologically normal serum tumor markers.

Post-chemotherapy retroperitoneal lymph node dissection is the standard of care for post-pubertal patients with normal serum tumor markers and residual masses >1cm.