Lactic acidosis and colon cancer: oncologic emergency?

We report the case of a 44-year-old woman who presented shortly after the diagnosis of metastatic colon cancer with profound lactic acidosis in the absence of tissue hypoperfusion or hypoxemia. Her acid-base disturbance was unresponsive to medical management but resolved after initiation of systemic chemotherapy. In addition to malignancy associated lactic acidosis, this case illustrates several other issues, including factors involved in choosing the initial chemotherapy regimen and sequencing subsequent therapies, and the role of carcinoembryonic antigen (CEA) in following response to treatment. It is important to report this case of a rare but serious complication of malignancy in order to increase recognition and understanding of this presentation.