S3242 Gallbladder Neuroendocrine Tumor: Case Report and Review of Medical Literature

Introduction: Gallbladder neuroendocrine tumor (GB-NET) is an extremely rare neoplasm, representing approximately 0.2% of all NETs. We report a case of GB-NET in a young man with chronic abdominal pain. A review of medical literature is provided. Case Description/Methods: The patient is a 30-year-old man with a history of hypertension and migraines. He presented with 6 months of right upper quadrant and epigastric pain. The pain was crampy, moderate, non-radiating, worsening, exacerbated by eating and associated with nausea, vomiting, diarrhea, and weight loss of 40 pounds. Abdominal computed tomography scan showed a heterogeneous liver. Abdominal US showed cholelithiasis. HIDA scan showed that radiotracer was present in the duodenum prior to filling the gallbladder. The patient underwent a laparoscopic cholecystectomy. The gallbladder pathology demonstrated GB-NET and cholelithiasis. There were multiple white lesions visualized on the surface of the liver. Biopsies were taken; pathology was consistent with NET. Colonoscopy with random colon biopsies was normal. Esophagogastroduodenoscopy showed moderate gastritis in the antrum and extrinsic compression from an enlarged lymph node onto the second portion of the duodenum. Endoscopic ultrasound demonstrated several malignant-appearing lymph nodes in the porta hepatis region. The largest lymph node measured 38 mm by 25 mm in diameter. Four passes of fine-needle biopsies were made with a 25-gauge needle using a trans-duodenal approach. Preliminary cytology was consistent with carcinoma with neuroendocrine features. Cytologic examination was positive for a well-differentiated GB-NET. Overall, the diagnosis was GB-NET with liver and lymph node metastatic disease. Oncology planned for chemo-radiation therapy as outpatient. The patient was discharged in stable condition. Discussion: GB-NETs are extremely rare with few reports in the medical literature. Diagnosis of GB-NETs can be challenging due to their rarity and vague presentation. GB-NETs exhibit nonspecific findings on imaging studies. GB-NETs are aggressive in nature, and more than 50% of patients present with metastatic disease, most commonly to the liver, bone, and lungs. The 1-, 2-, 3- and 5-year survival is 36.6%, 17.8%, 13.2% and 7.3%, respectively. The prognosis is poor with a median survival time of 7 months. Treatment with surgical resection combined with radiochemotherapy results in a better response than surgical resection alone. This case report illustrates that a multi-disciplinary approach is necessary for diagnosis and management of GB-NETs.