P2788 - A Rare Case of Spontaneous Tumor Lysis Syndrome as a Complication of Gastric Neuroendocrine Tumor

Marcel R. Robles, MD¹, Guoliang Zheng, MD², Mohammad Abudalou, MBBS³, Haoyang Wang, MD², Fang-Yu Liu, MD^2
1Tufts University School of Medicine, St. Elizabeth's Medical Center, Boston, MA; ²Tufts University School of Medicine, St. Elizabeth's Medical Center, Brighton, MA; ³St. Elizabeth's Medical Center, Tufts University School of Medicine, Brighton, MA

Introduction: Spontaneous tumor lysis syndrome (STLS) in solid tumors is rare and carries a high mortality rate. Treatment is supportive and early recognition and timely initiation of management is key. We present the first case of gastric neuroendocrine tumor complicated by STLS.

Case Description/Methods: A 53-year-old morbidly obese diabetic male presented with complaints of two week history of worsening colicky right upper quadrant abdominal pain associated with dark urine and watery diarrhea. Jaundice and abdominal tenderness were present on the exam. Workup revealed a cholestatic pattern of liver injury associated with acute kidney injury and elevated lactic acid (Table 1). CT abdomen/pelvis showed an exophytic 3.4 x 2.2 x 2.1 cm nodule at the tail of the pancreas along with hepatomegaly and hypodense lesions likely representing metastasis.



An ERCP/EUS with biopsy was performed as MRCP could not be obtained due to body habitus; a large infiltrative and ulcerated mass with no bleeding on the greater curvature of the gastric body was biopsied and multiple large 1-2cm polyps were noted. No evidence of biliary obstruction or pancreatic mass were found however multiple round lesions were identified endosonographically on the liver’s left lobe. Pathology revealed a grade 3 neuroendocrine carcinoma. Unfortunately shortly after the biopsy his course was complicated by gross electrolyte abnormalities including hyperkalemia 5.5 mmoL/L reaching to 7.7 mmoL/L with electrocardiographic changes, worsening kidney function and uric acid of 14 mg/dl (Table 1). Patient was diagnosed with STLS and started on rasburicase and due to persistent electrolyte abnormalities eventually started on dialysis.

Discussion: Patient presented with cholestatic liver injury from liver metastasis and due to high tumor burden was at risk of developing STLS. His preceding ERCP possibly prompted further tumor necrosis resulting in STLS. Development of hyperkalemia, hyperuricemia and acute renal failure without preceding chemotherapy prompted the diagnosis of grade 1 STLS per the Cairo-Bishop criteria. His normal phosphorus and calcium is not uncommon in STLS and it is postulated that tumor cells are able to recycle the released phosphorus. Treatment of TLS focuses on rehydration, urine alkalization, normalize uric acid and other electrolytes. If abnormality persists hemodialysis may be indicated. Although rare, STLS should be suspected in all patients with solid tumor if there is evidence of renal failure or electrolyte derangement.


Figure: Figure 1a. Noncontrast abdominal pelvis ct. Purple arrow shows 3.4x2.2x2.1 cm nodule at pancreatic tail.
Figure 1b. Noncontrast abdominal pelvis ct. Hepatomegaly amd liver cirrhosis with questionable intrahepatic hypodensities.
Figure 1c. Endoscopy. Large infiltrative and ulcerated mass at gastric antrum.
Figure 1d. Endoscopic Ultrasound. Multiple round hypoechoic lesions located on left lobe of liver.

Laboratory values on admission	Laboratory values during STLS	Laboratory values post dialysis
K+ : 4.7 mmol/L	K+: 5.5 mmol/L and 7.7 mmol/L	K+: 5.0 mmol/L
Ca++: 9/1 mg/dl	Ca++: 8.5 mg/dl	Ca++ 8.7 mg/dl
P: not obtained	P: 3.3 mg/dl	P: 2.6 mg/dl
Uric Acid: not obtained	Uric Acid: 14 mg/dl	Uric Acid: < 0.2 mg/dl
Cr: 2.7 mg/dl	Cr: 1.6 mg/dl	Cr: 0.9 mg/dl
Total Billirubin: 2.2 mg/dl	Total Billirubin: 6.8 mg/dl	Total Billirubin: not available
Direct Billirubin: 1.4 mg/dl	Direct Billirubin: 4.5 mg/dl	Direct Billirubin: not available
AST: 224 U/L	AST: 942 U/L	AST: not available
ALT: 148 U/L	ALT: 508 U/L	ALT: not available
Alkaline phosphatase: 381 U/L	Alkaline phosphatase: 420 U/L	Alkaline phosphatase: not available

Disclosures:
Marcel Robles indicated no relevant financial relationships.
Guoliang Zheng indicated no relevant financial relationships.
Mohammad Abudalou indicated no relevant financial relationships.
Haoyang Wang indicated no relevant financial relationships.
Fang-Yu Liu indicated no relevant financial relationships.


Marcel R. Robles, MD¹, Guoliang Zheng, MD², Mohammad Abudalou, MBBS³, Haoyang Wang, MD², Fang-Yu Liu, MD². P2788 - A Rare Case of Spontaneous Tumor Lysis Syndrome as a Complication of Gastric Neuroendocrine Tumor, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.