Abstract:Abstract: Objective: To investigate the clinical, imaging, and pathological characteristics, diagnosis, treatment, and prognosis of pancreatic acinar cell carcinoma (ACC). Methods: A retrospective analysis was conducted on clinical data of patients with pathologically confirmed ACC admitted to our institution from April 2015 to December 2024. The clinical manifestations, imaging and pathological features, diagnosis, treatment, and prognosis were summarized. Results: A total of 23 ACC patients were enrolled, including 15 males, with a mean age of 62 years. The most common presenting symptom was abdominal pain (13 cases), followed by jaundice, abdominal distension, and back pain. Tumors were located in the pancreatic head (15 cases), pancreatic body/tail (7 cases), and diffusely involved the entire pancreas (1 case). The mean tumor diameter was 54 mm. Tumors presented as solid (8 cases, 44.4%), solid with necrosis (5 cases, 27.8%), or cystic-solid (5 cases, 27.8%). Surgical resection was performed in 22 cases, while one patient underwent endoscopic ultrasound-guided biopsy due to metastasis to the №16 lymph node group and received comprehensive therapy. Pathologically, 21 cases were pure ACC, one case was mixed with ductal adenocarcinoma, and one case was mixed with neuroendocrine tumor. Lymph node metastasis was observed in 10 cases, and neurovascular invasion was present in 20 cases. R0 resection was achieved in 19 cases. Postoperative adjuvant chemotherapy was administered to 15 patients, with regimens including nab-paclitaxel plus gemcitabine (AG), gemcitabine plus oxaliplatin (Gemox), tegafur-gimeracil-oteracil potassium plus oxaliplatin (SOX), gemcitabine plus capecitabine (Gemcap), paclitaxel plus cisplatin (TP), and FOLFIRINOX. Among 21 patients with effective follow-up, the median overall survival was 26 months, and the median recurrence-free survival was 15 months. The 1-year and 3-year survival rates were 90.5% and 44.4%, respectively. The most common sites of initial recurrence were the liver (7 cases) and retroperitoneal lymph nodes (5 cases), followed by bone, lung, mesenteric lymph nodes, and local recurrence. Conclusion: Pancreatic acinar cell carcinoma is a rare malignant tumor characterized mainly by abdominal pain, often presenting as a solid mass with aggressive features such as frequent neurovascular invasion and lymph node metastasis. Surgical resection combined with adjuvant chemotherapy is the main treatment approach. Postoperative surveillance should focus on the liver and retroperitoneal lymph nodes for early detection of recurrence and metastasis.