Clinical Presentation. Although several staging schemes exist, the most widely used staging system is the one used at the St

Staging

Although several staging schemes exist, the most widely used staging system is the one used at the St. Jude's Children's Hospital (Table 9.6).

Table 9.6

Stage	St. Jude's staging system for childhood non-Hodgkin's lymphoma
I	Single tumor or nodal area outside the abdomen or mediastinum
II	Single tumor with regional node involvement Two or more tumors or nodal areas on one side of the diaphragm Primary gastrointestinal tumor (resected) with or without regional node involvement
III	Tumors or lymph node areas on both sides of the diaphragm Any primary intrathoracic disease or extensive intra-abdominal disease Any paraspinal or epidural tumors
IV	Any bone marrow or CNS involvement regardless of other sites of involvement

Similar to HL, NHL must be considered in any child with lymphadenopathy.

However, most children with B-cell lymphoma present with a palpable abdominal tumor or a mediastinal tumor. In children, NHL occurs predominantly in the chest and abdomen.

All NHL tumors grow rapidly and have a tendency for widespread systemic dissemination. All lymphatic tissue may be involved including that of lymph nodes, Peyer's patches, the thymus, Waldeyer's ring, pelvic organs, liver and spleen. Extralymphoid involvement can be seen in the skin, testis, bone and central nervous system (CNS).

Nearly 75% of children with lymphoblastic lymphoma present with a large, bulky, anterior mediastinal mass which may compress the trachea or create superior vena caval obstruction. Most common presenting symptoms include dyspnea, wheezing, stridor, swelling of the head and neck and sometimes dysphagia.

Pleural effusions (often bilateral) are frequently present; cytologic examination of the fluid can be diagnostic.

Up to 80% of children will present with cervical or axillary lymphadenopathy.

In patients with generalized lymphadenopathy and/or hepatosplenomegaly, bone marrow and CNS involvement should be suspected.

Bone marrow involvement may cause diagnostic confusion in determining whether the child has NHL with bone marrow involvement or leukemia. Although somewhat arbitrary, patients with greater than 25% bone marrow blasts are considered to have leukemia and children with less than 25% bone marrow blasts are considered to have lymphoma.

Small, noncleaved cell lymphomas most often (up to 90%) present in the abdomen as a fast growing tumor. Other sites of involvement include Waldeyer's ring, testis, nasal sinuses, bone, bone marrow, the central nervous system, peripheral lymph nodes and skin.

The African endemic form often appears at the orbit or in the jaw (>70%) while the sporadic form almost always presents as abdominal disease. The endemic form has a peak incidence at around 7 years of age and the sporadic form affects children from a broader age distribution.

More than half of abdominal cases involve the small bowel and probably originate in the Peyer's patches. The presenting symptoms are usually abdominal pain, anorexia, or tenderness. Rarely the presentation is intestinal obstruction caused by intussusception with the lymphoma as the lead point.

Large-cell lymphoma usually occurs at extranodal sites and is frequently widely disseminated at the time of presentation. It seldom involves the gastrointestinal tract. Primary sites include the skin, testis, eye, tonsils, soft tissues and sometimes the mediastinum. The peak incidence of the large-cell lymphoma is at puberty.

Patients may also present with B symptoms.

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