Palliative Radiotherapy Induced Severe Tumor Lysis Syndrome in a Patient With Multiple Myeloma With Skin Involvement: A Case Report and Review of Literature.

Background/aim: Radiotherapy (RT) has been rarely reported as a cause of tumor lysis syndrome (TLS). Therefore, the patient characteristics and details of RT-induced TLS remain unclear, which may delay diagnosis. Herein, we report a case of palliative RT-induced severe TLS in a patient with multiple myeloma (MM) with skin involvement along with literature review.

Case Report: A 75-year-old female with MM was referred to our department in February 2021 because of swelling and pruritus of the bulky tumor on her right breast and severe left leg pain. She had received chemotherapies and autologous peripheral blood stem cell transplantations since October 2012. We administered palliative RT (a single 8 Gy fraction) to the right breast, left tibia, and femur. On day 7 after RT, a shrinkage effect was observed on the right breast lesion, and left leg pain was relieved. Her laboratory results showed hyperuricemia, hyperphosphatemia, and hypercreatininemia. Initially, we considered acute renal failure (ARF) due to MM progression and planned for a follow-up after 1 week. On day 14 after RT completion, she experienced vomiting and anorexia. Her laboratory results became worse. She was admitted with the diagnosis of TLS and received intravenous fluid hydration and allopurinol. Unfortunately, the evolution was marked by severe clinical deterioration with anuria and coma, leading to death on day 35 after RT.

Conclusion: It is important to determine whether ARF is due to MM progression or TLS. The occurrence of TLS should be considered in the case of a rapidly shrinking bulky tumor while receiving palliative RT.