Ishaan Dharia, MD1, Adam Horowitz, MD2, Mitra Moazzami, MD3, Matthew Tick, DO4, Marie L. Borum, MD, EdD, MPH2 1Mount Sinai Hospital, New York, NY; 2George Washington University School of Medicine and Health Sciences, Washington, DC; 3Mayo Clinic, Rochester, MN; 4Amita Health Medical Group, Carol Stream, IL
Introduction: Hyperammonemic encephalopathy infrequently occurs as the presenting manifestation of a pancreatic neuroendocrine tumor (PNET) without associated hepatic failure. We present a rare case of a patient with neurologic decline requiring hospitalization who was diagnosed with a PNET and hyperammonemic encephalopathy without liver failure.
Case Description/Methods: A 59-year-old male attorney with hypertension presented to his primary care physician with a bilateral intention tremor and 2 weeks later developed progressively worsening cognition. His medical history was otherwise unremarkable. Upon hospitalization, vital signs were normal. A neurologic exam showed 1/4 recall and impaired attention. Labs revealed an elevated ammonia (219 μg/dL) and total bilirubin of 5.9 mg/dL (indirect 4.1 mg/dL). His CBC, CMP, AST/ALT/Alkaline phosphatase, coagulation panel, heavy metal screen, B1, B6, B12, folate, HIV, TSH, RPR, Lyme, infectious evaluation (including COVID), and lumbar puncture were normal. A brain MRI showed nonspecific bilateral basal ganglia changes. A RUQ ultrasound showed a pancreatic mass.
His mental status improved after 2 days of lactulose titrated to 3-4 soft bowel movements daily. A chest / abdominal / pelvic CT scan revealed an 11.3 cm heterogeneous pancreatic mass encasing the splenic artery and abutting greater than 50% of the superior mesenteric vein, without evidence of pulmonary or hepatic metastases. CA 19-9 was 13 U/mL. Ultrasound-guided biopsy revealed a well-differentiated neuroendocrine tumor (WHO Grade 2) positive for synaptophysin, Cam 5.2, Chromogranin A, Ki67 5%, and mitotic count < 2/5 mm2.
The patient underwent an open distal pancreatectomy and splenectomy; a liver nodule, positive for well-differentiated neuroendocrine cells, was found. 5/65 lymph nodes were positive for metastatic disease. Pathologic stage was T3N1M1a. A PET scan, done approximately a month after surgery, showed mild metabolic activity in the pancreatic body and multiple liver metastases not seen on CT scan. Currently, the patient is being followed by oncology and is receiving Lanreotide.
Discussion: This case is unusual because the patient presented with encephalopathy without evidence of hepatic failure. It is postulated that the encephalopathy was the result of microvascular portosystemic shunting due to unrecognized hepatic metastases. This case study emphasizes the potential need for advanced imaging in patients with PNET and encephalopathy when initial studies suggest no evidence of hepatic failure.
Disclosures: Ishaan Dharia indicated no relevant financial relationships. Adam Horowitz indicated no relevant financial relationships. Mitra Moazzami indicated no relevant financial relationships. Matthew Tick indicated no relevant financial relationships. Marie Borum indicated no relevant financial relationships.
Ishaan Dharia, MD1, Adam Horowitz, MD2, Mitra Moazzami, MD3, Matthew Tick, DO4, Marie L. Borum, MD, EdD, MPH2. P1101 - A Rare Care of Pancreatic Neuroendocrine Tumor and Hyperammonemic Encephalopathy, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.
