RESUMO
Tumor lysis syndrome (TLS) is a potentially life-threatening complication of chemotherapy. It usually occurs in rapidly proliferating hematological malignancies. TLS is deemed spontaneous (STLS) when it occurs prior to any cytotoxic or definite treatment. STLS is extremely rare in solid tumors. Here, we report a rare case of fatal STLS in a 47-year-old woman diagnosed with metastatic colon cancer. The patient developed acute renal failure with anuria, electrolyte disturbances, and metabolic acidosis before initiating chemotherapy. Despite appropriate management of TLS, including renal replacement therapy, she died within a few days from multiorgan failure. Only few other case reports of STLS associated with colon cancer have been reported in the literature.