When metabolic emergencies collide: A case of concurrent diabetic ketoacidosis and tumor lysis syndrome.

BACKGROUND: Tumor lysis syndrome (TLS) is an oncologic emergency increasingly recognized in highly chemosensitive cancers but is not often reported in solid tumors such as small cell lung cancer (SCLC) Diabetic ketoacidosis (DKA) may occur in patients receiving chemotherapy due to glucocorticoid exposure, metabolic stress, and insulin deficiency. Concurrent TLS and DKA may present with overlapping features of shock, acidosis, and acute kidney injury, creating a diagnostic challenge for emergency physicians.

CASE PRESENTATION: An 82-year-old man with extensive-stage small cell lung cancer (ES-SCLC) receiving carboplatin, etoposide, and atezolizumab presented to the ED five days post-chemotherapy with vomiting, hypotension, and tachypnea. Evaluation revealed severe anion-gap metabolic acidosis (pH 7.17, lactate 13.9 mmol/L), hyperglycemia (466 mg/dL), ketonemia, acute kidney injury, hyperuricemia (12.5 mg/dL), and hyperphosphatemia (8.2 mg/dL), meeting Cairo-Bishop criteria for clinical TLS as well as DKA. Respiratory viral PCR was positive for rhinovirus/enterovirus. The patient required ICU admission, insulin infusion, aggressive intravenous hydration and rasburicase.

CONCLUSION: This case underscores the importance of considering concurrent TLS in patients with recently treated chemosensitive malignancies who present with DKA, acute kidney injury, hyperuricemia, or hyperphosphatemia. Recognition of TLS may prompt disease-specific interventions including rasburicase administration, oncology consultation, and intensive monitoring beyond standard DKA management.