Spontaneous Tumor Lysis Syndrome as a Complication of Metastatic Breast Cancer: A Rare Case Report.

Tumor lysis syndrome (TLS) is a well-established potentially fatal condition which is considered an oncologic emergency. TLS typically develops from the rapid lysis of neoplastic cells after the commencement of cytotoxic treatment in patients with some kinds of lymphomas, especially the Burkitt variant, and acute lymphoblastic leukemia. Spontaneous TLS (STLS), a variant of TLS occurring in the absence of chemotherapy or radiation therapy, has been observed in non-Hodgkin lymphoma and acute leukemia, and rarely in solid neoplasms. In this paper, we present a 62-year-old woman with STLS, secondary to metastatic breast cancer. Unfortunately, she died because of complications of acute kidney injury, especially severe metabolic acidosis that was refractory to hemodialysis. Although it is infrequent, healthcare professionals should consider STLS as a probable consequence of breast cancer characterized by a high tumor burden and distant metastases.