| dc.description.abstract | 28.1 Malignant neoplasms are relatively rare in children. The annual incidence of cancer in children is 14/100,000; the probability for a newborn to develop cancer within the first 15 years of life is 215/100,000 or 1 in 470 children. Treatment of a child with cancer requires an interdisciplinary tumor team (pediatric oncologist, pediatric surgeon, radiotherapist, psychologist, pathologist, etc.). As a result of this teamwork and of multinational studies more than 70% of all malignancies in children today are cured (10-year survival). Information and guidance for parents are major issues in pediatric oncology. The aim of treatment is complete remission of the tumor with the lowest possible toxicity, chance of recurrence and risk of late sequelae. Compared to adults, carcinomas are very rare in children while central nervous system (CNS) tumors, sarcomas, and blastomas are more frequent. 28.2 General considerations Vascular lesions are divided in two types: hemangiomas and vascular malformations resulting from errors occurring during the development of vascular structures (arteries, veins, capillaries, lymphatics) 28.3 General considerations Benign hamartomatous tumor of the lymphatic system, characterized by multiple communicating lymphatic channels and cystic spaces May present as unilocular or multicystic masses, with a thin, often transparent, wall About 45% are apparent at birth, 85%-90% do not appear until the age of 24 months Head, neck, and oral (tongue) localization in about 75% of cases These tumors can grow to a large size and may be detected on prenatal scans Related to defective thoracic and right lymphatic duct drainage into the venous system in the neck More frequent on the left and sited at the angle of the jaw, extending into both triangles of the neck and ramifying through all normal neck structures Larynx involvement is rare Spontaneous regression is not characteristic 28.4 General considerations Malignant disease of the lymphatic system 60% nonHodgkin lymphomas of high malignancy 40% Hodgkin lymphoma Surgery mainly supports conservative therapy by • Diagnostic biopsy • Staging laparotomy or laparoscopy (in selected cases) • Port implantation for the chemotherapy 28.5 Neuroblastoma is the most frequent extra cranial tumor of childhood. In low stages it does not create any major surgical difficulty. The higher stages still constitute very challenging oncological and surgical problem with a number of questions still not answered. Possibility of maturation and spontaneous regression on one hand, and place of aggressive surgery and mega chemotherapy followed by bone marrow or stem cell rescue in poor prognosis cases on the other hand illustrate still existing difficulties in the treatment of this tumor. Prognosis, very favorable in low-staged tumors without molecular biology factors of risk, is still very poor in older children with extensive disease. 28.6 General considerations A congenital tumor containing derivatives of the three embryonic germ layers, arising at the tip of the coccyx Incidence 1 per 35,000-40,000 live births Unexplained female preponderance of 3:1 Partly solid, partly cystic tumor Expansion behind the rectum More than 90% of the tumors at birth are benign After 6 months 50% are malignant Neural deficit not usual May be associated with hydrops 28.7 General considerations In childhood the most common lung tumors are metastases of typical childhood tumors such as Wilms' tumor or neuroblastoma 28.8 General considerations Vesicular tumor representing the development of Echinococcus granulosus in the lung Additional, hepatic localization is present in more than 50% of pulmonary cases A high incidence is revealed in 8- to 12-year-old children, but cases in children 4-5 years old have been described in endemic areas such as the Mediterranean shores of Europe The infestation occurs via the digestive tract (see Sect. 27.5) Aerial infestation is a controversial hypothesis (pulmonary hydatid cysts with no hepatic association) 28.9 General considerations Rare tumors in the mediastinum (see Table 28.10) 28.10 General considerations The two main liver tumors in childhood are hepatoblastoma and hepatocellular carcinoma Hepatoblastoma • Highly malignant • Mostly in children under 5 years old Hepatocellular carcinoma • Less frequent than hepatoblastoma • Most often associated with an underlying liver disease (inborn error of metabolism, liver cirrhosis of any origin) • Most often in children more than 5 years old 28.11 Nephroblastoma is the most frequent intra abdominal solid tumor of childhood. Treatment of nephroblastoma is classical example of successful modern oncology combining chemotherapy, surgery and radiotherapy. Currently, 85% of patients with that disease can be cured. Epidemiology, ethiology, history, diagnostics, staging and classification of pathology variants, treatment including specific characteristics of vena cava involvement, stages 4 and 5, the pros and contras for nephrone sparing surgery in unilateral nephroblastoma and outcome are described. 28.12 A variety of tumors may locate in the ovary. Ovarian tumors, if low staged, constitute nearly purely surgical problem. Successful adnexectomy cures those patients and further treatment is usually unnecessary. Number of those tumors are also the classical examples of usefulness of tumor markers - both for diagnosis and follow-up. Inoperable ones and/or those with metastatic spread to the lymph nodes or distant organs are frequently chemo responsive. The neoadjuvant chemotherapy offers the chance of reduction of the tumor size and decrease of the extension of the disease. Secondary surgical treatment has the chance to be complete in those cases. Normalization of the tumor markers is predictive both for feasibility of surgical resections and for outcome. 28.13 Testicular tumors have a lot of biological and oncological similarities with the ovarian ones. Types of tumors, majority of markers, treatments in use and prognosis are not markedly different. Classical types of childhood tumors of testis, if low staged, require the orchiectomy via an inguinal approach as the curative procedure. Advanced tumors may create the difficulties due to the local infiltration, metastatic spread to the lymph nodes and/or distant organs. Number of these tumors are chemo responsive, thus secondary resections may appear easier, complete and curative. Markers are good predictive factors for outcome and timing of surgery. 28.14 General considerations Undifferentiated mesenchymatous cells (muscles, connective tissue, fat, vessels) Morbidity is 8.4 per 1,000,000 live births 6% of the malignant tumors are in children The most frequent tumor in children is rhabdomyosarcoma An ill-defined lump should always raise suspicion of a soft tissue tumor with infiltrative growth Non-capsulated tumor, but, at times, with a pseudocapsule 28.15 General considerations Originates in the myoblasts and can appear at any site in the body It is one of the more frequently found solid tumors of childhood, with an incidence of between 8% and 13% of all solid tumors Metastases appear mainly in the lung, lymph nodes, bones, and liver Pediatric surgeons contribute by taking biopsy samples (either fine needle aspiration cytology or surgical biopsy) that enable the staging of disease and thus determination of further treatment, which is multidisciplinary 28.16 General information Tumor of mesenchymal tissues of the bone marrow It is the second most frequent bone tumor in children More frequent sites are pelvis and diaphyses of long bones Differential diagnoses: osteomyelitis, metastases, histiocytosis X, leukemia 28.17 General information Neoplasm of mesenchymal cells that form bone and osteoid It is the most frequent malignant bone tumor in children Localized mainly close to the knee joint (mostly lower femur), sometimes in the upper humerus as well Appears mainly after the age of 10 years © 2009 Springer-Verlag. | en |
