TEACHING POINTS■ Burkitt's lymphoma is a B-cell non-Hodgkin's lymphoma (NHL). Abdominal tumors can double in size every 24 hours.
■ Rapidly proliferating tumor cells die naturally because they outgrow their supply of nutrients, but chemotherapy also causes massive cell death in rapidly growing cells. Tumor lysis syndrome is a life-threatening condition that can lead to renal failure and cardiac arrhythmias.
■ Short courses of intensive multi-agent chemotherapy are the standard of care. Neurotoxicity, mucositis, cardiac insufficiency, and infertility are side effects of some of these chemotherapeutic agents. A recent international clinical trial demonstrated that doses of cyclophosphamide and doxorubicin could be reduced without altering efficacy and survival in intermediate-risk NHL lymphoma.
CASE
A 2-year-old boy presented to the emergency department (ED) with an 8-day history of increasing abdominal pain and distention, intermittent vomiting, and lower-than-usual activity. Despite a decreased appetite, the child had gained 2.5 lb over the preceding week, and swelling was evident in his legs. He had been recently treated for constipation; no blood was detected in the stool. His urine output was normal, and he had no significant night sweats or bruising.
On initial physical examination, the child was afebrile. Vital signs included heart rate, 132 beats per minute; respiratory rate, 24 breaths per minute; and BP, 119/56 mm Hg. He weighed 12.1 kg. There were no murmurs, rubs, or gallops on cardiac examination, and breath sounds were normal on auscultation. His abdomen was distended and firm. Bowel sounds were hypoactive. The right lower quadrant was tender to palpation. He had collateral veins on his abdomen, presumably resulting from increased intra-abdominal pressure. A rectal examination revealed no palpable mass. Cervical and inguinal lymph nodes were shotty and nontender. His lower extremities demonstrated 1+ pitting edema. On the morning he presented to the ED, the patient had a palpable right lower quadrant mass measuring 2×3 cm; by evening of the same day, the mass measured 7×7 cm.
Pertinent laboratory test results obtained during the first week of evaluation and therapy are listed in Table 1. At presentation, urinalysis was normal, with a urinary pH of 7.0. By evening on the day of presentation, the patient's lactate dehydrogenase (LDH) had increased from a morning level of 542 IU/L to 1,435 IU/L. His initial uric acid level, measured in the evening, was 9.2 mg/dL.
Abdominal ultrasonography showed a mildly thickened bowel with no evidence of intussusception. CT of the abdomen and pelvis showed bulky soft-tissue densities that filled the abdomen and retroperitoneum, consistent with lymphadenopathy. Diffuse bowel wall thickening was noted, without obstruction. There was a small amount of ascites. Solid masses were observed in both kidneys. A matted mass of bowel and lymph nodes was seen in the right lower portion of the abdomen (Figure 1). CT of the chest showed no abnormalities above the diaphragm.
Based on a suspected diagnosis of Burkitt's lymphoma, the patient was transferred to a children's cancer hospital. He was started on IV fluids (5% dextrose in 0.5N saline with 60 mEq/L of sodium acetate) at 1.5 times the maintenance rate to alkalinize his urine and prevent precipitation of uric acid crystals in the kidneys. IV allopurinol was given to prevent uric acid nephropathy. The child was taken emergently to the OR for exploratory laparotomy, tissue biopsy, and central venous catheter placement. Opening the abdomen revealed a moderate amount of ascites and a baseball-sized necrotic mass adjacent to the terminal ileum. When the mass was sampled for biopsy, air was noted at the base of the biopsy cavity. The mass had eroded through the wall of the small intestine, and removal of the biopsy sample had unroofed a contained perforation. A segmental ileal resection was necessary to remove the necrotic bowel. Because the surgeon anticipated that the severity of the chemotherapy would put a small-bowel anastomosis at risk for leakage and fistula, he proceeded with a right lower quadrant ileostomy and formation of a blind pouch with the remaining colon (Hartmann's procedure). A bone marrow biopsy showed no evidence of lymphoma. The CSF was negative for malignant cells.
Chemotherapy was initiated as soon as possible following
a minimal postoperative recovery. Four days after his initial presentation, the patient was started on a course of "reduction-phase" COP (cyclophosphamide, vincristine [Oncovin], and prednisone) chemotherapy, along with intrathecal methotrexate.