You Can’t Always Blame the Chemo: A Rare Case of Spontaneous Tumor Lysis Syndrome in a Patient with Invasive Ductal Cell Carcinoma of the Breast

Tumor lysis syndrome (TLS) is an oncologic emergency characterized by metabolic and electrolyte abnormalities, observed during the destruction of tumor cells. While it is commonly seen during cytotoxic treatment of hematologic malignancies, it is rarely seen or suspected in solid tumors. The incidence of spontaneous tumor lysis (before cancer treatment) in solid malignancies is even rarer. Herein, we present the case of a spontaneous tumor lysis syndrome (STLS) in a woman who presented with chest pain and was found to have metastatic ductal cell carcinoma of the breast. She presented with acute renal failure and demonstrated all laboratory derangements consistent with TLS, despite not being on chemotherapy. Fortunately, her clinical status improved with prompt treatment, but the long-term effects of TLS can be fatal if not recognized and managed immediately. This case highlights that early recognition and appropriate treatment can be lifesaving. Furthermore, it demonstrates the importance of maintaining a high clinical suspicion in all patients with malignancy, whether hematologic or solid, of the possibility of TLS, even in the absence of chemotherapy.