Publicationdate update 21-3-20<br><br>由于CT和MRI的廣泛應(yīng)用，囊性胰腺病變?cè)絹碓蕉嗟乇话l(fā)現(xiàn)。某些胰腺囊腫是癌前病變，可能轉(zhuǎn)化為產(chǎn)生黏液的腺癌。<br><br>盡管胰腺囊腫惡變的總體風(fēng)險(xiǎn)很低，但因其有惡變的風(fēng)險(xiǎn)而引起患者焦慮，因而需要進(jìn)一步的檢查。<br><br>對(duì)于較大的囊性病變，通?？梢苑譃榱夹詽{液性囊腺瘤（ serous cystic neoplasms，SCN）、癌前黏液性囊性病變（ mucinous cystic neoplasms，MCN）和導(dǎo)管內(nèi)胰腺黏液性腫瘤（ intraductal pancreatic mucinous neoplasms，IPMN），但對(duì)于較小的病變，很難進(jìn)行鑒別。<br><br>很多胰腺囊腫難以明確，因此需要制定指南來指導(dǎo)隨訪和診治。 <b>分類：</b><div><b><br></b>假性囊腫<br>常見的囊性腫瘤:<ul><li>導(dǎo)管內(nèi)乳頭狀黏液性腫瘤，IPMN </li><li>漿液性囊性腫瘤，SCN</li><li>粘液性囊性腫瘤，MCN</li></ul>罕見的囊性腫瘤:<br><ul><li>實(shí)體性假乳頭狀上皮性腫瘤，SPEN </li><li>囊性變腫瘤:</li><li>腺癌-神經(jīng)內(nèi)分泌腫瘤</li></ul></div> 方法：<br>當(dāng)發(fā)現(xiàn)囊性胰腺病變時(shí)，第一步是確定病變是假性囊腫還是囊性腫瘤。<br>上圖是簡(jiǎn)化路線圖<br><br><ul><li>假性囊腫——有慢性或急性胰腺炎、酒精濫用、結(jié)石疾病或腹部創(chuàng)傷史時(shí)可考慮假性囊腫。檢查發(fā)現(xiàn)實(shí)質(zhì)或?qū)Ч茆}化和胰腺周圍脂肪浸潤提示慢性胰腺炎可能。如果囊腫淀粉酶低于250 u/ml，則排除假性囊腫。<br></li><li>囊性腫瘤-無胰腺炎或外傷史，囊腫有內(nèi)隔、實(shí)性成分、中央瘢痕或壁鈣化。</li><li>粘液性囊性腫瘤——通常是一種充滿黏液的單眼囊腫，有時(shí)伴有壁鈣化，主要見于40 - 60歲的女性。常位于體側(cè)或尾側(cè)，病檢示以卵巢型間質(zhì)為特征。 </li><li>漿液性囊性腫瘤-通常是含有漿液的微囊性病變。SCN可能有多種表現(xiàn)，其中45%為微囊性(囊腫＜2 cm)， 32%大囊性，18%微囊性和大囊性混合，5%固體 。</li><li>微囊性SCN血管豐富，增強(qiáng)CT顯示實(shí)性，因此很容易與胰腺癌混淆。MRI可以清楚地顯示病變的微囊。 </li><li>分支胰管型IPMN -腫瘤看起來像SCN，但無疤痕或鈣化。MRCP或T2WI可能顯示胰管相連接是高度特異性的特征，但在許多病例中檢測(cè)到與胰管相通。</li></ul> 左側(cè)CT：有兩個(gè)單房性囊腫，右側(cè)腹膜后脂肪條紋?；颊哂幸认傺撞∈贰Ｒ虼俗钣锌赡艿脑\斷是胰腺假性囊腫。<br><br>右側(cè)CT：一名36歲女性在胰腺尾部發(fā)現(xiàn)一個(gè)囊腫，這是超聲偶然發(fā)現(xiàn)的。囊腫有一個(gè)厚而不規(guī)則的邊緣，并含有“獨(dú)立”的固體成分。因此最有可能的診斷是囊性腫瘤。<br> MRI與CT<br>CT可以顯示大部分胰腺病變，但有時(shí)不能顯示囊性成分。<br>MR伴加權(quán)T2WI及MRCP能較好地顯示囊腫的囊性及內(nèi)部結(jié)構(gòu)，并具有顯示囊腫與胰管關(guān)系的優(yōu)勢(shì)，如所示的IPMN。<br><br>CT顯示漿液性囊性腫瘤(SCN)。MRI能更好地顯示中央瘢痕。<br> 對(duì)于有些病例CT檢查也有其一定優(yōu)勢(shì)：比如CT可以更好顯示SCN的中央鈣化或黏液性囊性腫瘤(MCN)的外周鈣化。 CT圖像顯示黏液性囊性腫瘤伴有分隔和周圍鈣化。 MRI通常比CT有更高的診斷價(jià)值。<br>MRI可以顯示胰腺積液的囊性及其內(nèi)部結(jié)構(gòu)。<br>MRI顯示壞死性胰腺炎典型的壁狀壞死、典型的囊內(nèi)壞死碎片的胰液集聚。<br> MRI顯示病灶有多個(gè)小囊腫。這可能是漿液性囊性腫瘤或分支胰管型IPMN。<br>可以囊性病變與胰管的連接，因此這是分支胰管型IPMN。 <div><b>假性囊腫要點(diǎn)：</b><br></div><div><br><ul><li>無實(shí)性成分的單房囊腫，中央瘢痕或壁鈣化。</li><li>胰酶、血液和壞死組織集聚。</li><li>磁共振檢查可以發(fā)現(xiàn)囊性病變中的特異性的碎片。</li><li>胰腺炎或腹部外傷史。</li><li>囊腫在4-6周內(nèi)形成——通常隨時(shí)間減小——有時(shí)也會(huì)擴(kuò)大或感染。</li><li>在胰腺的任何部位或腹部的任何地方，有時(shí)甚至在胸部縱膈也有囊腫。</li></ul><br>上圖CT顯示急性胰腺炎患者上腹部有一個(gè)大囊腫(圖)。<br><br>注意這里也有一些腹水和胸腔積液。有囊壁強(qiáng)化。<br></div> 上圖CT顯示兩個(gè)大囊腫（患者45歲女性，有外傷史）。<br><br>注意腹膜后間隙的一些脂肪條紋(箭頭所指)。<br>結(jié)合影像學(xué)檢查及病史，診斷最大可能是創(chuàng)傷性胰腺假性囊腫。<br> 假性囊腫大多發(fā)生在胰周，但也有很少的病例假性囊腫會(huì)擴(kuò)展到縱隔。<br><br>上圖患者患有慢性胰腺炎。<div>多個(gè)假性囊腫一直延伸至縱隔，壓迫心臟(紅色箭頭)。<br></div> <div><b>囊性腫瘤-鑒別診斷</b></div><div>無胰腺炎或外傷史的患者因考慮胰腺囊性腫瘤。<br><br><b><i>囊性腫瘤的形態(tài)學(xué)特征如下:</i></b><i><b> <br></b></i><br><ul><li>厚的不規(guī)則的邊緣</li><li>分隔</li><li>固體成分</li><li>胰管擴(kuò)張＞3mm、鈣化</li><li>腫瘤囊腫抽出的液體淀粉酶水平低</li></ul>上表中列出囊性腫瘤的一些鑒別特征。<br>在許多情況下，由于囊腫往往太小，因此不能作出明確的斷。<br>然而，診斷漿液性囊性腫瘤是很重要的，因?yàn)檫@是唯一沒有惡性潛能的腫瘤。當(dāng)出現(xiàn)癥狀時(shí)，是由于囊腫體積增大。<br></div> <b>年齡和性別</b><div><b><br></b>粘液性囊性腫瘤<br><ul><li>MCN僅見于平均年齡為47歲的中年女性。</li><li>迄今僅報(bào)告12例男性病例。</li></ul><br>漿液性囊性腫瘤<br><ul><li>SCN也最常見于女性(75%)，中位年齡58歲。</li></ul>實(shí)心假乳頭狀上皮腫瘤<br><ul><li>SPEN僅見于年輕女性(88%)，平均年齡29歲。</li><li>它是一種不常見的實(shí)性腫瘤，可能有囊性成分。</li></ul><br>因此有以下規(guī)則:<br><ul><li>祖母-漿液性囊性腺瘤(SCN)</li><li>母親-黏液性囊性腫瘤(MCN)</li><li>子女-實(shí)性假乳頭狀上皮性腫瘤(SPEN)</li></ul></div> <b>漿液性囊性腫瘤</b><br><ul><li>良性腫瘤，但大的腫瘤有增大的趨勢(shì)并引起癥狀。</li><li>通常在《奶奶》中出現(xiàn)。</li><li>SCN可能有不同的表現(xiàn)，如微囊性(45%)、巨囊性(32%)、微囊性與巨囊性混合(18%)和固態(tài)(5%)(4)。</li><li>微囊性或蜂窩狀囊腫，中央有瘢痕(30%)和鈣化(18%)。</li><li>大囊性腫瘤占10%，與假性囊性和粘液性囊性腫瘤難區(qū)分。</li><li>分成小葉的表面。</li><li>囊腫與胰管間無通訊。</li><li>有時(shí)可見強(qiáng)化，與囊性神經(jīng)內(nèi)分泌腫瘤鑒別具有挑戰(zhàn)性。</li><li>腫瘤生長(zhǎng)速率>4厘米:高達(dá)20毫米/年。</li></ul> 病理標(biāo)本顯示多個(gè)微囊，使腫瘤呈分葉狀。<br>大囊性漿液性囊性腫瘤很少見，雖然是良性的，但在外觀上與潛在的惡性大囊性黏液性囊性腫瘤相似。 漿液性囊性腫瘤的特征性表現(xiàn)是中央有瘢痕，有時(shí)伴有鈣化。<br>有時(shí)這種腫瘤的微囊性成分在CT上很難識(shí)別。<br>MR將更好地識(shí)別內(nèi)部架構(gòu)。<br>MRI在判斷囊腫是否與胰管連通時(shí)也很有用，可以將其與支管型IPMN區(qū)分開來(見下文)。<br>病理標(biāo)本顯示一個(gè)囊性腫瘤，包括多個(gè)小囊腫和中央瘢痕。 CT-image of a 51 year old woman with a history of gallstones and abdominal pain.<br>一位51歲女性，有膽結(jié)石及腹痛病史。<br>胰腺頭部有一低密度灶，伴有中央鈣化。<br>病灶呈分葉狀輪廓。<br>繼續(xù)進(jìn)行MR檢查。<br> MRI能更好地顯示病變的形態(tài)特征(圖)。<br>T2WI示多囊性病變。<br>可見中央低信號(hào)，因中央瘢痕伴鈣化。<br>雖然有些囊腫相當(dāng)大，但這仍然是漿液性囊性腺瘤(大囊性腺瘤)的特征性表現(xiàn)。 另一例漿液性囊性腫瘤(圖)。<br>右側(cè)對(duì)比增強(qiáng)圖像顯示胰腺實(shí)質(zhì)低密度病灶伴有中央鈣化和細(xì)微的分隔強(qiáng)化<br>注意在CT上很難看出這些病變的囊性你可能會(huì)認(rèn)為是胰腺癌。 很容易顯示這些病灶的囊性(圖)。<br>T2WI顯示分葉狀高強(qiáng)度病變，伴有中央瘢痕，這是SCN的特征。 漿液性微囊性腺瘤與分支胰管型IPMN或?qū)Ч軆?nèi)乳頭狀黏液性腫瘤很難區(qū)分。<br>IPMN常與胰管相連，但在許多情況下很難看到其連接。<br>該圖像顯示71歲男性T2WI，有體重減輕史，無上腹部不適。<br>這最初被認(rèn)為是一個(gè)分支管IPMN，但結(jié)果是一個(gè)SCN。<br>注意中心的低強(qiáng)度。<br>這是SCN中的瘢痕組織。<br>還要注意特征分葉狀表面。 另一例漿液性囊腺瘤。<br>注意中心高密度影。<br>有時(shí)與高血管囊性神經(jīng)內(nèi)分泌腫瘤鑒別是困難的，但在這種情況下中央鈣化是有幫助的。<br> 胰腺尾部為囊性病變，中央有鈣化瘢痕(箭頭所指)。<br>盡管有些囊腫大于2cm，但由于中央瘢痕、多房外觀和分葉狀輪廓，這種表現(xiàn)仍然是漿液性囊性腫瘤的典型表現(xiàn)。<br>該病人腹部不適歸因于腫瘤，切除后證實(shí)為漿液性囊性腫瘤。 這是切除的標(biāo)本。<br>腫瘤與脾臟關(guān)系密切，因而連同脾臟一起切除。<br> 另一例典型的漿液性囊性腫瘤(圖)。<br>在胰腺頭部有一個(gè)微囊性病變并有一個(gè)中央瘢痕。<br>這位病人感到腹部有個(gè)腫塊。<br>除此之外，沒有其它不適。<br>因?yàn)榍谐馕吨鴱V泛的手術(shù)，所以決定跟蹤病灶。<br>在5年的隨訪期間，沒有生長(zhǎng)，患者沒有其他癥狀。 <div><b>粘液性囊腺瘤</b></div><div><ul><li>癌前腫瘤-可轉(zhuǎn)變?yōu)轲ひ盒阅蚁侔?lt;/li><li>只出現(xiàn)在女性身上——通常是“母親”—平均年齡:40-50歲</li><li>大囊性具厚壁分隔。</li><li>25%可見周圍鈣化。這一發(fā)現(xiàn)可以讓你做出特定的診斷。</li><li>胰腺尾部和身體的位置(95%)。</li><li>大多數(shù)有癥狀，表現(xiàn)為無癥狀腹痛</li></ul></div> CT-images of a 32 year-old female with pain in the upper left quadrant radiating to the back. <br><br>There is a large cyst in the pancreatic tail with peripheral calcification.<br>There is subtle septation as seen on the left image and wall thickening. <br><br>You may have to enlarge the image to see the septation. <br><br>A specific diagnosis of a MCN can be made. CT-image of a 46 year old female with vague right abdominal complaints. <br><br>The imaging findings are:<br><br>septated cyst of 7 cm in the pancreatic head.<br>smooth capsule.<br>no lobulation. <br>no connection to the pancreatic duct. <br>MRI revealed a septated pancreatic head cyst of 7 cm with a smooth capsule without lobulation and no connection to the pancreatic duct. <br><br>Surgery showed a low grade mucinous cystadenoma with ovarian stroma. CT images of a 30 year old female with a history of a biliary pancreatitis and cholecystectomy.<br>She had sudden increased left abdominal pain.<br><br>US showed increased size of a cystic lesion, which was diagnosed as a pseudocyst. <br><br>The CT however showed a non-lobulated cystic lesion in the pancreatic tail with internal enhancing septation without connection to the pancreatic duct (fig).<br><br>Continue with the MRI... The T1W-image post gadolinium better depicts the internal septations.<br><br>Pancreatic tail resection revealed a 14 cm mucinous cystadenoma including ovarian stroma. <div><b>Intraductal Papillary Mucinous Neoplasm</b></div><div>key findings:<br><br><ul><li>Mucin producing tumor in main pancreatic duct or branch-duct.</li><li>Location: pancreatic head >> tail and corpus.</li><li>Must have communication with pancreatic duct. Best seen with MRCP.</li><li>Can be multifocal.</li><li>Main-duct IPMN has imaging features distinct from branch-type.</li><li>Branch-duct type can look like other cystic neoplasms</li><li>Macroscopic specimen of a IPMN showing mucinous tumor, with extensive mucin producing papilary neoplasm (arrow).</li></ul></div> <b>Main-duct IPMN</b><br>On imaging Main-duct IPMN is usually distinct from branch-duct IPMN, but sometimes there is a mixed type.<br><br>Scroll through the images of a large main duct and branch-duct IPMN.<br>There is obstruction of the common bile duct with dilatation of the intrahepatic bile ducts (blue arrows).<br>Notice the extremely widened main pancreatic duct (red arrow). Normal T2WI and heavily T2WI with fatsat of a large main duct IPMN with extremely dilated pancreatic duct. This patient presented with pancreatitis.<br>The MRCP shows both a main-duct as well as a branch-duct IPMN (arrow).<br>IPMN is a lesion with malignant potential.<br><br>Signs of malignancy are:<br><br><ul><li>Pancreatic duct > 8 mm - as in this case.</li><li>Solid node in duct.</li><li>Mass around the pancreatic duct.</li><li>Enlarged choledochal duct.</li></ul> CT-images of an IPMN with a dilated pancreatic duct (blue arrows).<br>Notice enhancing solid nodule in the pancreatic head (red arrow).<br>Continue with the ultrasound-image. The US-image shows a large branch-duct component within the pancreatic head. <b>Branch-duct IPMN</b><br>The CT-image shows a hypodense lesion in the pancreatic head.<br>This could be an adenocarcinoma, but the low density makes you think of a cystic tumor.<br>The microcystic appearance raises the possibility of a serous cystic neoplasm although there is no calcified scar.<br>On MRCP the cystic nature is better appreciated and there is a connection to a widened duct (blue arrow). A detail nicely demonstrates that some of the mucus-filled branches are seen in cross-section and some longitudinally. The heavily T2WI nicely demonstrates the multicystic lesion with the connection to the pancreatic duct.<br><br>This was diagnosed as a branch-duct IPMN. CT-images of a patient with a branch-duct IPMN who choose not to have surgery. <br><br>Over time growth of the tumor is seen with dilatation of the main duct indicating malignant transformation.<br><br>Sometimes it takes 5-8 years before a transformation is seen. Another branch-duct IPMN found on screening with two nodules (circle and arrow).<br><br>T1W-images with fatsat before (left image) and after contrast (right image). <br><br>EUS with contrast agent revealed 2 foci without enhancement most likely mucus plugs. <br><br>6 years later the cyst was unchanged. 75 year old male with a 2.7 cm side branch IPMN in the pancreatic head (circle). <br><br>During follow up one year later dilatation of pancreatic duct was seen.<br>EUS showed a resectable adenocarcinoma. <div><b>Uncommon Neoplasms with specific findings</b></div><div>Solid Pseudopapillary Neoplasm<br>key findings:<br><br><ul><li>Very uncommon neoplasm seen in women 20-30 years (daughter).</li><li>Solid and cystic neoplasm with capsule and with early 'hemangioma-like' enhancement. </li><li>Sometimes intratumoral hemorrhage</li><li>CT-images of a 26 year old woman with a large mass in the pancreatic head and metastases in the liver.</li><li>In the center there is lack of enhancement due to cystic or necrotic degeneration.</li></ul></div> Solid tumor with cystic components in a 16 year old female diagnostic of solid pseudopapillary tumor. <b>Neuroendocrine tumor with cystic degeneration</b><br>key findings:<br><br><ul><li>Non-functioning endocrine neoplasm</li><li>Also called islet cell tumor</li><li>Hypervascular with ring-enhancement. This is unlike serous cystic neoplasms that enhance from the center and more solid)</li></ul><br><br>CT-images of a 61 year old woman with weight loss.<br>There is a large mass in the body of the pancreas that is hypervascular, unlike an adenocarcinoma, with some cystic or necrotic parts. CT-image of a neuroendocrine tumor with central necrosis.<br>Sometimes this can simulate a cystic component.<br>Notice the peripheral enhancement. Report and Management<br><br>In the table a checklist of what to mention in the report and the relative and absolute indications for resection according to the European evidence-based guidelines on pancreatic cystic neoplasms (2).<br><br>Continue with the guidelines for management. The frequency of imaging follow-up depends on the presence of indications and fitness for surgery as can be seen in the table.<br><br>Although these management guidelines apply to IPMN, in general practice we use these criteria also for pancreatic cysts of unknowm origin and suspected mucinous cystic neoplasms. However in suspected Mucinous Cystic Neoplasm a cyst size ≥ 4 cm is an absolute criterium for resection, whereas for IPMN it is a relative indication. <div><b>Imaging protocol</b></div><div><b><br></b></div><div>The initial MRI should be done using a dedicated pancreatic protocol (tab).<br>A possible follow-up protocol for lesions < 3 cm may consist of coronal and axial T2 single shot sequences and T1 weighted precontrast and no post contrast.<br>Possibly adding diffusion weighted images to minimize risk of missing a concomitant pancreatic carcinoma.<br><br>We have chosen to follow-up cysts smaller than 3 cm without intravenous gadolinium with the rest of the sequences the same. If we find a possible new nodule we would return the patient and repeat the MR scan with IV gadolinium to evaluate for enhancement.</div>