Case report and review of the literature: Aggressive atypical cystic fibromatosis of the pancreas, a rare locally aggressive benign tumor

Xianhong YangZhenji XuYangyingqiu LiuTao Feng^*

• Zibo Central Hospital, Shandong, China

Aggressive fibromatosis of the pancreas (AFP) is a rare, nonepithelial, aggressive benign soft tissue tumor of the pancreas characterized by the β-catenin positive expression. Due to its rarity, it is often misdiagnosed as a malignant pancreatic tumor. In this report, we present a case of aggressive atypical cystic fibromatosis localized specifically to the pancreas. We emphasize the key imaging features essential for diagnosing and assessing the aggressiveness of this condition, along with its pathological characteristics, pathogenesis, and surgical treatment. Progressive delayed enhancement, marked restricted diffusion, aggressive features can aid in differentiation, and nuclear β-catenin positivity are highly characteristic. A 22-year-old female was admitted following the incidental discovery of a cystic-solid pancreatic mass during a routine medical examination. This patient underwent preoperativeultrasound, computed tomography, and magnetic resonance imaging. The identified lesion was subsequently surgically resected, and histopathological examination confirmed the presence of AFP. Notably, the tumor was found incidentally, as the patient was asymptomatic. Radiologists should consider the possibility of aggressive fibromatosis in patients presenting with pancreatic tumors, as surgical resection can lead to a cure. Therefore, comprehensive imaging analysis is crucial for making an accurate preoperative diagnosis and providing appropriate treatment.