INTRODUCTION
Testicular tumours account for 1–2% of pediatric sol- id tumours. Pediatric testis tumours are pathologi- cally and clinically distinct from their adult counter- parts, and these differences demand a different man- agement algorithm. While nearly 90% of adult testis tumours are seminomas, embryonal carcinomas or non-seminomatous mixed germ cell tumours, such tumour types account for fewer than 10% of tumours in children. Conversely, the two most common prep- ubertal tumours – yolk sac and teratoma – account for fewer than 1% each of adult tumours. Gonadal stromal tumours are relatively common in children, but quite rare in adults. These differences in histolog- ic sub-type result in significant differences in natural history with metastases occurring in 61% of adult pa- tients but in only 9% of children. The critical histo- logic changes appear to occur at puberty. Therefore, tumours occurring in postpubertal adolescent males are best managed under adult algorithms.
Most testicular tumours present as a painless hard mass, though rarely they may present with pain relat- ed to an acute bleed. On physical examination, a mass that cannot be separated from the testis is assumed to be a testis tumour until proven otherwise. Ultra- sound is very helpful in making this distinction when the physical examination is unclear. Rarely, testis tu- mours may present with a reactive hydrocele. If a hy- drocele is large and firm enough to preclude palpa- tion of the testis, an ultrasound should be obtained.
A significant proportion of prepubertal testis tu- mours are benign. Tumours may be of germ cell or stromal origin (the exception being gonadoblasto- mas, which contain elements of both). Yolk sac tu- mours, the most common, are always treated as po- tentially malignant. Teratomas, the second most common tumour, are universally benign in prepu- bertal patients. Gonadal stromal tumours have gen- erally behaved in a benign fashion in children, except for some undifferentiated stromal tumours and occa- sional Sertoli cell tumours in children over 5 years of age.
Pre-operative evaluation includes an ultrasound scan and determination of the α-fetoprotein (AFP) level. Ultrasound is helpful in distinguishing intra- testicular from extratesticular scrotal masses. It can also determine whether the entire testis is replaced with tumour, or if there is some normal testicle that
may be salvaged if the tumour is benign. Serum AFP is elevated in 90% of children with yolk sac tumours.
AFP is very specific for yolk sac tumour, but may be physiologically elevated in normal infants (including those with benign tumours). Generally speaking, a child over 1 year of age with a testicular mass and an elevated AFP can be assumed to have a yolk sac tu- mour. Infants under 1 year of age with an elevated AFP may have benign tumours, though AFP levels are rarely greater than 100 ng/ml in normal children over 6 months of age. The ultrasonographic charac- teristics of various testis tumours have been de- scribed. However, the findings are not specific enough to alter management, which is based on the AFP level and whether salvageable testis is present. If the tumour is felt to be malignant or if it completely replaces the testis precluding testis-sparing surgery, then an inguinal orchiectomy is performed. Tumours that are likely to be benign based on AFP level, and that appear to have salvageable normal testis on ultrasound, should be managed initially with an exci- sional biopsy and frozen section analysis. If a benign histology is confirmed then the testis is closed with absorbable suture and returned to the scrotum. If the biopsy reveals a malignant tumour (usually yolk sac) or potentially malignant tumour (such as an undif- ferentiated stromal tumour or a Sertoli cell tumour in an older child), then an inguinal orchiectomy should be performed. If a teratoma is diagnosed and the child is near pubertal age, the surrounding pa- renchyma should be examined for its pubertal status.
If the tubules are immature, then the tumour may be treated as benign. However, if the tubules show evi- dence of maturation, the tumour should be treated as potentially malignant since some adult teratomas be- have in a malignant fashion.
Retroperitoneal lymph node dissection plays a
very limited role in prepubertal testis tumours. Un-
like adults, only a minority of prepubertal patients
with metastases have metastases limited to the retro-
peritoneum, and metastatic disease is very respon-
sive to chemotherapy. Furthermore, the complication
rate following retroperitoneal lymph node dissection
(RPLND) is significantly higher in children than in
adults. The only clear indication for RPLND is the
persistence of a retroperitoneal mass following
chemotherapy – a rare occurrence.
Jonathan Ross 478
Figure 45.1
The patient is placed in the supine position. If pos- sible, a caudal block has been applied. An inguinal skin incision is made extending laterally from just above the pubic tubercle following Langer’s lines.
The subcutaneous tissue is divided with cautery. The superficial epigastric vein is often encountered in the lateral corner of the incision and should be con- trolled with cautery.
The superficial fat may then be separated bluntly with retractors exposing Scarpa’s fascia. Scarpa’s fas- cia is grasped with forceps and opened with scissors.
The tissue between Scarpa’s fascia and the external oblique aponeurosis is developed by gentle spreading and Scarpa’s fascia is then divided throughout the length of the incision.
A small incision is made in the external oblique aponeurosis near the lateral corner of the incision so that it comes through above the internal ring where it is unlikely to injure the ilioinguinal nerve. After bluntly pushing the ilioinguinal nerve down from the undersurface of the aponeurosis, the aponeurosis is opened with scissors through the external ring.
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Figure 45.2
With blunt dissection the plane behind the cord is developed and a vessel loop passed behind it. With a combination of blunt and cautery dissection this plane is developed proximally to the internal ring
and a rubber shod clamp used to occlude the vessels
at the internal ring. Then the testis is delivered into
the operative field and the gubernaculum is divided
with cautery.
Figure 45.2
Jonathan Ross 480
Figure 45.3a–c
If the pre-operative assessment suggests a malignan- cy, then the hydrocele sac is left intact and the speci- men ligated and divided at the internal ring without manipulation of the testicle (not shown). If the pre- operative evaluation is equivocal with regard to the malignant nature of the tumour, then the hydrocele sac is opened after draping off the testis to isolate it from the field (drapes not shown). A wedge excision of the tumour with a margin of normal parenchyma
is undertaken and a frozen section analysis obtained.
If the tumour is benign on frozen section, then the testis is closed with 5/0 absorbable suture and re- turned to the scrotum. If the tumour is malignant, then the cord is doubly suture-ligated with nonab- sorbable suture and divided at the internal ring. The entire specimen is sent for histopathological evalua- tion. The incision is closed in layers with absorbable suture.
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a b c
Jonathan Ross 482
CONCLUSION
Surgical complications are rare following inguinal orchiectomy or tumour excision. Local recurrence following simple excision has not been reported for benign tumours or following inguinal orchiectomy for malignancy. However, local recurrence in the scrotum has occurred following transcrotal biopsy of malignant tumours, and a scrotal approach for pos- sible malignancies must be avoided. The occasional complications that can occur following inguinal or- chiectomy are scrotal infection or haematoma and retroperitoneal haematoma. These can generally be avoided with meticulous surgical technique and thorough haemostasis of the raw surface of the inner scrotum.
The survival of children with testis tumours de- pends on the histology of the tumour and the pres- ence or absence of metastatic disease. Children with teratomas, epidermoid cysts, and benign stromal tu- mours do well with excision alone. No long-term fol- low-up is required. Patients with yolk sac tumour re-
quire a metastatic evaluation consisting of a compu- terized tomography (CT) scan of the abdomen and pelvis, a chest X-ray, and determination of AFP level.
The half-life of AFP is 5 days. Approximately 80% of patients will have stage 1 disease (disease limited to the testicle) confirmed by a negative chest X-ray and CT scan and normalization of the AFP level. These patients may be observed closely without adjuvant therapy. Follow-up includes CT scans every 2 months and chest X-rays and AFP levels monthly for 2 years, followed by observation at longer intervals. The re- lapse rate for stage 1 patients is approximately 20%
and virtually all patients can be salvaged with chem- otherapy. Patients who present with metastatic dis- ease are treated with adjuvant chemotherapy, and survival is better than 90%. Radiation plays no role in the primary treatment of these tumours. Metastatic stromal tumours, while exceedingly rare, are resist- ant to treatment. Survival is low for this group.
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