胰腺囊性肿瘤（pancreatic cystic neoplasms， PCN）是指起源于胰腺导管上皮和（或）间质组织的囊性肿瘤性病变，大致可以分为黏液性肿瘤和非黏液性肿瘤。前者主要包括导管内乳头状黏液性肿瘤（intraductal papillary mucinous neoplasm， IPMN）、黏液性囊性肿瘤（mucinous cystic neoplasm， MCN），而后者主要包括浆液性囊性肿瘤（serous cystic neoplasm， SCN）、实性假乳头状肿瘤（solid-pseudopapillary neoplasm， SPN）和囊性神经内分泌肿瘤（cystic neuroendocrine tumor， cNET）。不同类型的PCN具有差异化的生物学行为，部分PCN存在恶变的风险，术前采用CT、MRI检查鉴别恶性肿瘤具有重要意义。MCN恶变率为5%~20%，恶性指征为直径大于等于4 cm，为手术指征。IPMN占PCN的22%，主胰管型及混合型IPMN恶变风险可高达70.9%和76.5%，分支胰管型IPMN的恶变风险为2.8%~10.7%。IPMN高危征象包括，强化的实质成分或壁结节直径≥5 mm、主胰管扩张（管径≥10 mm）、梗阻性黄疸，并推荐这些患者行手术治疗。SCN好发于中老年女性，男女比例为1:3，多为良性，浆液性囊腺癌罕见，仅占胰腺SCN的0.1%。2015版胰腺囊性疾病诊治指南推荐，所有的SPN均应行手术治疗。当SPN肿瘤包膜不完整、肿块直径大于6 cm或位于胰尾部可能具有较高的侵袭性和远处转移能力。cNET约占PCN的7%。PCN影像学诊断需结合病史及病变成分等，诊断要点为，MCN为几乎均发生于女性的胰体尾部类圆形、厚壁囊性肿瘤，常呈“囊内囊”表现；IPMN好发于老年男性，主胰管型IPMN表现为除外梗阻性因素的主胰管弥漫性明显扩张或节段性扩张，分支胰管型IPMN通常表现为与胰管相通的条管状囊性肿瘤，混合型IPMN则兼有两者表现；SCN为分叶状、薄壁寡囊或多囊蜂窝状肿瘤；SPN为好发于青年女性的较大类圆形囊实性肿瘤；cNET为边缘呈环形或新月形明显强化的囊实性肿瘤。国内外指南关于PCN手术指征的选择存在较大争议，且胰腺手术难度高、术后并发症多，给PCN的规范化治疗带来了挑战。识别PCN的影像学特点，明确影像学诊断，具有临床意义。

Pancreatic cystic tumors (PCN) refer to cystic tumor lesions originating from the epithelium and/or interstitial tissue of the pancreatic duct. PCN can be roughly divided into mucinous tumors and non-mucinous tumors. The former mainly includes intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN), while the latter mainly includes serous cystic neoplasms (SCN) and solid-pseudopapillary neoplasms (SPN) and cystic neuroendocrine neoplasms (cNET). Different types of PCNs have differentiated biological behaviors, and some types of PCNs have a risk of developing a malignancy. Preoperative identification of PCN malignancy on CT and MRI imaging is of great significance. Malignant indications for MCN are surgical indications， such as a diameter greater than or equal to 4 cm. IPMN accounts for 22% of PCN, and the risk of malignancy in main pancreatic duct type and mixed type IPMN can reach up to 70.9% and 76.5%, while the risk of malignancy in branch pancreatic duct type IPMN is 2.8%-10.7%. High risk signs of malignancy for IPMN include enhanced parenchymal or diameter of parietal nodules ≥ 5 mm, main pancreatic duct dilation (≥ 10 mm), and obstructive jaundice, and surgical treatment is recommended for these patients. SCN is more common in middle-aged and elderly women, with a male to female ratio of 1:3. Serous cystadenocarcinoma is rare, accounting for only 0.1% of pancreatic SCN. The 2015 edition of the Diagnosis and Treatment Guidelines for Pancreatic Cystic Diseases recommends that all SPNs patients should undergo surgical treatment. When the tumor of SPN with incomplete capsule, the mass diameter larger than 6 cm, and the tumor located in the tail of the pancreas, may have a higher ability of invasiveness and distant metastasis. cNET accounts for approximately 7% of PCN. Imaging diagnosis should be combined with medical history and lesion components, etc. The diagnostic point for SPN on image is that MCN is a round, thick walled cystic tumor that almost exclusively occurs in females in the body and tail of the pancreas body, often presenting as an “intracystic cyst”. IPMN is more common in elderly men. The main pancreatic duct type of IPMN presents as diffuse or segmental dilation of the main pancreatic duct, excluding obstructive factors. Branch pancreatic duct type of IPMN usually presents as tubular cystic tumors that communicate with the pancreatic duct, while mixed type of IPMN combines both manifestations. SCN is a lobulated, thin-walled oligocystic or multicystic honeycomb tumor. SPN is a larger round cystic solid tumor that is more common in young women. cNET is a cystic solid tumor with significantly enhanced circular or crescent shaped edges. There is significant controversy in domestic and foreign guidelines regarding the selection of indications for PCN surgery, and pancreatic surgery is difficult with many postoperative complications, posing challenges to the standardized treatment of PCN. Identifying the imaging characteristics of PCN and clarifying imaging diagnosis has clinical significance.