Paediatric Surgical Oncology

Neuroblastoma is the most common extracranial malignancy of childhood with an incidence of 9.5 cases per million children. Most children are diagnosed around the age of 2 years. Staging is complex and depends on numerous patient and tumour related variables. Patients are stratified into risk groups upon which treatment is based. Treatment ranges from active surveillance without intervention for the lowest risk patients to combinations of chemotherapy, surgery, radiotherapy, bone marrow transplantation and targeted drug therapy for high-risk patients.

Wilms tumour is the second most common extracranial malignancy and the most common kidney tumour of childhood with an incidence of 7.6 cases for every million children under 15 years of age. This tumour was the first malignancy in which chemotherapy was noted to play a significant role in improving survival after surgery. Staging is dependent on the extent of the tumour and the presence of absence of metastases. Some children will require chemotherapy before surgery. Most children will have the affected kidney removed and then go on to have chemotherapy after surgery. Some will also need radiotherapy. Most children with this tumour are cured.

Other tumours of the kidney are far rarer than Wilms tumours. These include but are not limited to:

• renal cell carcinoma
  
• rhabdoid tumour
  
• clear cell sarcoma
  
• congenital mesonephric blastoma

Rhabdomyosarcoma is the third most common extracranial malignancy and the most common soft tissue sarcoma of childhood with an incidence of 4.4 cases per million children. Staging is based on numerous variables including the size and site of the tumour, whether it had been completely surgically removed, its genetic characteristics and the presence of absence of metastases. Therapy usually consists of a combination of chemotherapy before and after a surgical resection. Radiation therapy is also frequently used with this tumour.

Non-rhabdomyosarcoma soft tissue sarcoma is a group of over 50 types of rare tumours. It accounts for 3% of childhood cancer and just less than half of the cases of childhood sarcoma. Staging is quite similar to rhabdomyosarcoma. Therapy is varied according to the type of tumour diagnosed and usually involves surgery. For a small number of these tumours, therapy that targets specific genes and their mutations is available.

Germ cell tumours account for approximately 3% of tumours in children under 15 years of age and 14% of tumours between 15 and 19 years of age. There are a few different kinds of germ cell tumours. Most are mature teratomas and are benign. The next most common are immature teratomas. These are usually benign but can exhibit malignant behaviour. Truly malignant germ cell tumours comprise a few different types. Germ cell tumours can occur in the testes, ovaries or at extragonadal sites like the head and neck, chest, abdomen or pelvis. Evaluation of the tumour requires certain blood tests and imaging with CT and MRI. Treatment varies from surgery alone for mature teratomas, to combinations of surgery, chemotherapy and occasionally radiotherapy for malignant germ cell tumours.