Spontaneous Tumor Lysis Syndrome Revealing Advanced Ovarian Carcinoma: From Oncologic Emergency to Complete Pathologic Response

Tumor lysis syndrome (TLS) is an oncologic emergency characterized by metabolic abnormalities resulting from rapid tumor cell breakdown. It is most frequently observed following cytotoxic therapy in hematologic malignancies and is rarely encountered spontaneously in solid tumors. Spontaneous TLS associated with ovarian carcinoma remains exceptionally uncommon. A 53-year-old woman with no pertinent medical history presented with progressive abdominal distension, dyspnea, and oliguria. Laboratory evaluation demonstrated acute kidney injury with a serum creatinine of 4.09 mg/dL, accompanied by hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia, fulfilling the Cairo-Bishop criteria for clinical TLS. Computed tomography (CT) revealed massive ascites and a 16.2 × 15 × 15 cm pelvic mass without evidence of obstructive uropathy. Ascitic fluid cytology demonstrated metastatic carcinoma. Tumor markers showed a cancer antigen (CA)-125 level of 445 U/mL and a CA-125:carcinoembryonic antigen ratio greater than 25, strongly supporting a gynecologic primary malignancy. In the absence of recent chemotherapy or other precipitating factors, spontaneous TLS secondary to previously undiagnosed ovarian carcinoma was diagnosed. The patient was treated with aggressive intravenous hydration, rasburicase, electrolyte correction, and close multidisciplinary monitoring, resulting in rapid normalization of metabolic abnormalities and recovery of renal function without dialysis. Following stabilization, the patient underwent neoadjuvant carboplatin-paclitaxel chemotherapy followed by interval cytoreductive surgery. Histopathologic examination demonstrated a complete pathologic response, with no residual invasive carcinoma. Follow-up positron emission tomography/CT imaging showed no evidence of residual or metastatic disease, and CA-125 normalized to 5.2 U/mL. This case highlights spontaneous TLS as a rare initial manifestation of advanced ovarian carcinoma and emphasizes the importance of early recognition and prompt intervention. Timely management may reverse life-threatening metabolic complications, facilitate definitive oncologic treatment, and result in favorable long-term outcomes.