UNPLEASANT SURPRISE: A CASE OF SPONTANEOUS TUMOR LYSIS SYNDROME FROM EXTRANODAL DIFFUSE LARGE B-CELL LYMPHOMA

Abstract

TOPIC: Pulmonary Manifestations of Systemic Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Approximately a third of the patients with diffuse large B-cell lymphoma present with extranodal involvement.[1] Pleural effusion in diffuse large B-cell lymphoma (DLBCL) foreshadows a poor prognosis.[2] We present a rare case of spontaneous tumor lysis in extranodal DLBCL with unknown primary source, presenting with pleural effusion. CASE PRESENTATION: A 76-year-old man with history of hypertension, diabetes, chronic kidney disease, peripheral vascular disease with bilateral below-knee amputation and stroke, presented with 2 weeks of worsening weakness, decreased appetite, right-sided facial droop, difficulty speaking & trouble urinating; denied hematuria, dysuria, cough, chest pain, abdominal symptoms or history of HIV. On admission, he was hypothermic. Vital signs were stable otherwise. He was a&ox1 and somnolent. Labs remarkable for Na 131mmol/L, bicarbonate 15mmol/L, BUN 84.3mg/dl, creatinine(Cr) 3.72mg/dl, pro-BNP 21699pg/ml, hemoglobin 7.3g/dl, procalcitonin 1.34ng/ml. CT head showed no acute intracranial pathologies. Chest X-ray showed moderate right pleural effusion with partial loculation and right base patchy airspace opacity. Chest CT showed moderate-sized loculated right pleural effusion and small left pleural effusion. He was admitted for community-acquired pneumonia and was started on IV ceftriaxone and azithromycin. On day 2, thoracentesis was done and pleural fluid sent for analysis. On day 5, he was more somnolent and hyperkalemic to 6.8 with anion gap 24, BUN 84mg/dl, Cr 4mg/dl & bicarb 9mmol/L. EKG noted prolonged PR interval. He was started on aggressive IV fluids and sodium bicarbonate drip. Potassium remained elevated despite treatments with calcium gluconate, insulin, dextrose and potassium binders. Uric acid was 31mg/dl, phosphorus 15mg/dl and lactate dehydrogenase 882U/L. Given the lab abnormalities suspicious for tumor lysis syndrome, oncology was consulted. CT abdomen showed nonspecific thickening of the terminal ileum and bladder wall but no lymphadenopathy nor splenic enlargement. Urine cytology negative for malignant cells. Final pathology of pleural fluid showed diffuse large B cell lymphoma with Ki-67 of 80-90%. Rasburicase was given urgently for tumor lysis syndrome. Uric acid became undetectable the next day but Cr was 5.4. After discussion with family, the patient was placed under comfort-care measures as chemotherapy wouldn't be well-tolerated. He passed on day 13. DISCUSSION: Spontaneous tumor lysis syndrome is a rare oncological emergency with multiorgan failure, characterized by an elevation of uric acid, hyperphosphatemia, hypocalcemia, hyperkalemia with no active chemotherapy[3]. Our patient presented with unilateral pleural effusion without detectable lymphadenopathy or hepatosplenomegaly: an extremely rare presentation. CONCLUSIONS: If Cairo-Bishop definition is met, there should be high suspicion for spontaneous tumor lysis syndrome as early treatment can be life-saving. REFERENCE #1: Castillo JJ, Winer ES, Olszewski AJ. Sites of extranodal involvement are prognostic in patients with diffuse large B-cell lymphoma in the rituximab era: an analysis of the Surveillance, Epidemiology and End Results database. Am J Hematol. 2014 Mar;89(3):310-4. doi: 10.1002/ajh.23638. Epub 2014 Feb 19. PMID: 24273125. REFERENCE #2: Porcel, J.M., Cuadrat, I., García-Cerecedo, T. et al. Pleural Effusions in Diffuse Large B-Cell Lymphoma: Clinical and Prognostic Significance. Lung 197, 47–51 (2019). REFERENCE #3: Hsu HH, Chan YL, Huang CC. Acute spontaneous tumor lysis presenting with hyperuricemic acute renal failure: clinical features and therapeutic approach. J Nephrol. 2004 Jan-Feb;17(1):50-6. PMID: 15151259. DISCLOSURES: No relevant relationships by Ahmed Al-Ghrairi, source=Web Response No relevant relationships by Jini Hyun, source=Web Response No relevant relationships by Phyu Thin Naing, source=Web Response No relevant relationships by Rohan Paramesh, source=Web Response