Pediatric Extranodal Lymphoma.

Lymphoma is the third most common pediatric neoplasm. Non-Hodgkin lymphoma (NHL) accounts for nearly half of cases and commonly involves extranodal sites. Compared with adults, this histologic spectrum of pediatric NHL is very narrow and consists of aggressive tumors. Patients typically present with widespread disease. Generally, NHL occurring in children includes Burkitt lymphoma, lymphoblastic lymphoma, diffuse large B-cell lymphoma, and anaplastic large cell lymphoma. Staging and assessment of therapeutic response are usually based on FDG-PET/CT. Due to the increased susceptibility of young patients to the effects of ionizing radiation, alternative methods of imaging are being explored.