Fatal acute tumor lysis syndrome with metastatic breast carcinoma.

A 53-year-old woman presented with an extensively metastatic and rapidly growing breast adenocarcinoma, markedly elevated lactate dehydrogenase, and mildly elevated blood urea nitrogen. She received 5-fluorouracil, doxorubicin, and cyclophosphamide. Eighteen hours after chemotherapy she was noted to have hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia, and acute renal failure. She experienced cardiac arrest and died 72 hours after receiving chemotherapy. A postmortem liver biopsy revealed adenocarcinoma undergoing necrosis. This case represented the acute tumor lysis syndrome that occurred after chemotherapy of breast carcinoma. Patients with metastatic breast carcinoma and similar presentations should be considered for prophylactic therapy with allopurinol and hydration before chemotherapy.