The differential diagnosis for lymphomas in children includes leukemia, rhabdomyosarcoma, nasopharyngeal carcinoma, germ cell tumors, and thymomas. Nonmalignant diagnoses include infectious mononucleosis (EBV infection), branchial cleft and thyroglossal duct cysts, cat scratch disease (Bartonella henselae), bacterial or viral lymphadenitis, mycobacterial infection, toxoplasmosis, and even tinea capitis, all of which can produce significant lymphadenopathy that can mimic lymphoma. Patients with acute abdominal pain from Burkitt lymphoma may be misdiagnosed as having appendicitis.
The generally accepted treatment for childhood Hodgkin disease is a combination of chemotherapy and low-dose, involved-field radiation therapy. Chemotherapy usually consists of some combination of cyclophosphamide, vincristine, procarbazine, doxorubicin, bleomycin, vinblastine, prednisone, and etoposide. In general four to six courses of combination chemotherapy are given. Selected low-risk patients may be cured with chemotherapy alone, without radiation therapy.
Figure 156-1 Chest x-ray of a 15-year-old boy demonstrating a large superior anterior mediastinal mass (large arrows) compressing the trachea and deviating it rightward (arrowheads). Biopsy revealed non-Hodgkin lymphoma.
Distant, noncontiguous metastases are common in childhood NHL. Systemic chemotherapy is mandatory and should be administered to all children with NHL, even those with clinically localized disease at diagnosis.
T-cell lymphoblastic lymphoma and anaplastic large cell lymphoma generally are treated with aggressive multidrug regimens similar to the regimens used in ALL. The main drugs used in the treatment of mature B-cell NHL are cyclophosphamide, moderateto high-dose methotrexate, cytarabine, doxorubicin, ifosfamide, and etoposide. Surgery and radiation therapy rarely are used because the disease is rarely localized and is highly sensitive to chemotherapy.
The short-term complications from the treatment of lymphoma are similar to other pediatric malignancies and commonly include immunosuppression, related sequelae from myelosuppression, nausea, vomiting, and alopecia. Late adverse effects include second malignant neoplasms (acute myeloid leukemia or myelodysplasia, thyroid malignancies, and breast cancer), hypothyroidism, impaired soft tissue and bone growth, cardiac dysfunction, and pulmonary fibrosis.
Children and adolescents with Hodgkin disease are classified as low, intermediate, or high risk according to stage andnodal bulk. The prognosis is generally excellent. There is an approximately 90% 5-year overall survival rate, approaching 100% for low-risk patients and 70% to 90% for high-riskpatients. For NHL prognosis also is related to stage. The overall3-year survival rates for B-cell, T-cell, and large cell NHL are70% to 90%.
Most central nervous system (CNS) tumors in children and adolescents are primary tumors that originate in the CNS and include low-grade astrocytomas or embryonic neoplasms (medulloblastoma, ependymoma, germ cell tumor). In contrast CNS tumors in adults are high-grade astrocytomas or secondary tumors that are metastatic from other carcinomas. CNS tumors also may arise in patients previously treated with radiation therapy. CNS tumors are likely multifactorial in etiology. The classification of CNS tumors is complex and evolving, with the World Health Organization classification being the most complete and accurate system.