P1824 - A Rare Presentation of Extra-Pancreatic Acinar Cell Carcinoma as Duodenal Polyp

Prathyusha Chalasani, MD, Bashar Hmoud, MD
Garden City Hospital, Garden City, MI

Introduction: Acinar cell carcinoma(ACC) is a rare malignant tumor that accounts for 1-2% of all exocrine pancreatic neoplasms and usually arises in the pancreatic parenchyma. Primary extra-pancreatic acinar cell carcinoma is a rare malignancy and has been reported in the gastrointestinal tract, liver, lymph nodes and perinephric space till now. Surgical resection is the mainstay of treatment for acinar cell carcinoma of pancreatic or extra-pancreatic origin. Here we report a rare case of pancreatic acinar cell carcinoma presenting as duodenal polyp. As of our knowledge there are currently no reported cases of acinar cell carcinoma presenting as duodenal polyp in the duodenal bulb.

Case Description/Methods: 77-year old female was admitted to the emergency department due to fatigue and melena for four days. After initial resuscitation, she underwent esophagogastroduodenoscopy (EGD) which showed a single angiodysplastic lesion with bleeding in the second portion of the duodenum which was treated with argon plasma coagulation and a single 10mm pedunculated polyp in the duodenal bulb. Polypectomy was not attempted as patient was having bleeding. She presented at a later date for repeat EGD which during which the polyp was removed. Pathology revealed acinar cell carcinoma in association with a mixed type adenoma with high-grade dysplasia. Patient underwent a CT abdomen pelvis which did not show any pancreatic mass. Patient was referred to oncology for further management.

Discussion: Extra-pancreatic acinar cell carcinoma is rare. There were 21 cases of extra-pancreatic pancreatic type ACC published in PubMed, recently in 2021 with extra-pancreatic ACC in the right perinephric space. The proposed management of primary ACC or extra-pancreatic ACC is surgical resection followed by adjuvant chemotherapy although no standard chemotherapy regimen has been established for patients with ACC or extra-pancreatic ACC, and no large-scale randomized controlled trials have yet been conducted for this disease. In cases reported previously, patients have undergone radical surgical resection followed by adjuvant chemotherapy. In our case, patient underwent polypectomy and was referred to oncology. Whether adjuvant therapy is recommended for patients after surgery is controversial, and most adjuvant therapy is individualized with variable and non representative response rates. Hence, further studies should be undertaken to determine the pathogenesis, prognosis and treatment strategy, including appropriate chemotherapeutic regimens.


Disclosures:


Prathyusha Chalasani, MD, Bashar Hmoud, MD. P1824 - A Rare Presentation of Extra-Pancreatic Acinar Cell Carcinoma as Duodenal Polyp, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.