P1850 - Small Cell Carcinoma of the Gallbladder: A Rare Case of Aggressive Neuroendocrine Neoplasm in a 56-Year-Old Man

Award: Presidential Poster Award

Wendy T. Garzon-Siatoya, MD¹, Khalid Aloum, MD¹, Lisnaldy C. Ramirez-Osoria, MD¹, Arnold N. Forlemu, MD, MPH², Camelia Ciobanu, MD³, Amr Dokmak, MD³, Praneeth Bandaru, MBBS, MD³, Manasa Ginjupalli, MD³, Hamsika Moparty, MD⁴, Anuj R. Sharma, MBBS³, Sajana Poudel, MD⁵, Vijay Reddy Gayam, MD⁶, Vikash Kumar, MD⁷, Raissa Nana Sede Mbakop, MD⁴, Denzil Etienne, MD³, Nithan Narendra, MD¹, Madhavi Reddy, MD, FACG^3
1St. Barnabas Hospital, Bronx, NY; ²Brooklyn Hospital Center, Athens, GA; ³Brooklyn Hospital Center, Brooklyn, NY; ⁴The Brooklyn Hospital Center, Brooklyn, NY; ⁵John H. Stroger, Jr. Hospital of Cook County, Chicago, IL; ⁶University of Texas Southwestern Medical Center, Dallas, TX; ⁷Creighton University School of Medicine, Brooklyn, NY

Introduction: Gallbladder neuroendocrine neoplasms (GB-NENs) are exceptionally rare, making up less than 0.2% of all gastrointestinal neuroendocrine tumors, with a higher incidence among women (~68%). GB-NENs are classified into typical carcinoid, atypical carcinoid, and small cell carcinoma (SCC), the latter being the most aggressive and poorly differentiated. We present a case of a man diagnosed with SCC of the gallbladder.

Case Description/Methods: A 56-year-old man from Guyana with no significant medical history presented to the emergency department with worsening right-sided abdominal and rectal pain for two months. He reported intermittent pain associated with subjective weight loss of 10-15 lbs. He denied nausea, vomiting, constipation, diarrhea, flushing, wheezing, melena, hematochezia, or headache. He had no history of surgeries, smoking, alcohol, or drug use. He mentioned a remote family history of an aunt with colon cancer. Physical examination was unremarkable. Initial laboratory findings included elevated aspartate aminotransferase at 84 U/L (reference range:8-34 U/L), normal alanine transaminase at 26 U/L (reference range: 6-55 U/L), and normal total bilirubin and alkaline phosphatase levels. A CT scan of the abdomen and pelvis revealed a gallbladder mass suggestive of malignancy (Fig.1A). MRI with contrast confirmed a lobulated, heterogeneous gallbladder mass at the fundus measuring 6.3x5.0x3.5 cm (Fig.1B,C) likely invading the hepatic flexure of the colon, with liver metastasis and a dilated common bile duct up to 2.6 cm. Carcinoembryonic antigen was elevated at 3.5 ng/mL (reference range: ≤3 ng/mL), while alpha-fetoprotein and CA 19-9 were negative. A percutaneous biopsy of the gallbladder mass revealed small-cell, poorly differentiated neuroendocrine carcinoma, positive for synaptophysin (Fig.1D), AE1/3 (focal), and CD56 (Fig.1E), with a Ki-67 proliferative index of 90% (Fig.1F). He underwent a laparoscopic cholecystectomy and was referred to oncology for further treatment.

Discussion: SCC of the gallbladder is often asymptomatic in its early stages and is typically diagnosed when is advanced, with presenting symptoms related to locally advanced or metastatic disease. Specific diagnostic tests for GB-NENs are lacking, making histopathologic and immunohistochemical staining decisive for diagnosis. Early detection and multimodal therapy, including surgical resection, chemotherapy, and radiotherapy, are crucial for improving survival. Further studies are needed to optimize treatment strategies.



Disclosures:


Wendy T. Garzon-Siatoya, MD¹, Khalid Aloum, MD¹, Lisnaldy C. Ramirez-Osoria, MD¹, Arnold N. Forlemu, MD, MPH², Camelia Ciobanu, MD³, Amr Dokmak, MD³, Praneeth Bandaru, MBBS, MD³, Manasa Ginjupalli, MD³, Hamsika Moparty, MD⁴, Anuj R. Sharma, MBBS³, Sajana Poudel, MD⁵, Vijay Reddy Gayam, MD⁶, Vikash Kumar, MD⁷, Raissa Nana Sede Mbakop, MD⁴, Denzil Etienne, MD³, Nithan Narendra, MD¹, Madhavi Reddy, MD, FACG³. P1850 - Small Cell Carcinoma of the Gallbladder: A Rare Case of Aggressive Neuroendocrine Neoplasm in a 56-Year-Old Man, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.