Spontaneous tumour lysis secondary to gastric adenocarcinoma

We present a case of a man in his 70s who presented with worsening rectal and back pain associated with weight loss, dyspnoea and brownish discolouration of urine. Physical examination noted abdominal distention and epigastric tenderness. Laboratory investigations revealed acute kidney injury, hyperkalaemia, hyperphosphataemia and hyperuricaemia. Contrast CT of the abdomen/pelvis showed multiple, low-density masses throughout the liver, suspicious for metastatic disease. Oesophagogastroduodenoscopy demonstrated a large, fungating, infiltrative and ulcerated mass in the gastric body and lesser curvature of the stomach. Surgical pathology confirmed invasive moderately differentiated gastric adenocarcinoma. He met both the laboratory and clinical criteria for spontaneous tumour lysis syndrome (STLS) as per the Cairo-Bishop criteria. He was managed with aggressive fluid hydration, rasburicase and allopurinol, resulting in improvement in his renal function and laboratory findings. STLS of solid organ tumours, especially gastric adenocarcinoma, is rare and requires early detection with timely management to ensure favourable outcomes.