Cystic tumors of the pancreas: the radiologist.

摘要: The increasing use of cross-sectional imaging has led to the realization that prevalence cystic neoplasms is higher than initially estimated. 10,37 These lesions are problematic for clinicians because many them have histologic features cellular atypia or invasive carcinoma, thus forcing a decision surgery. initial descriptions appearing in North American literature were previously reported by Japanese radiologists mid-1980s. 12,13,14 From these early reports, it was evident findings could be used classify based on cyst size, presence and location calcifications, relationship pancreatic ducts. concordant with classic pathology Compagno Oertel. 8,9 microcystic adenoma presents as mass characterized dense, internal, lacelike, honeycombed matrix composed fibrous setae. setae may so dense components go unrecognized. When calcifications present, they invariably within central portion lesion (Fig. 1). Using thin-section CT scanning current MR technology, spaces enmeshed can delineated. sufficiently large, result pancreaticobiliary ductal obstruction. 4,19 At time this seen, all its components, considered benign. There been scattered case reports synchronous adenocarcinoma patients serous cystadenoma 23 malignant epithelial lining cysts. 26 author seen encased major peripancreatic vessels occurred hepatic metastases; however, do not display typical clinical course characterizes those adenocarcinoma. Many who followed up imaging; none developed metastatic disease. unilocular macrocystic mass, without internal septations mural nodules, detected, diagnosis becomes less clear-cut. Unilocular masses mucinous cystadenocarcinoma. Most morphology 2). assumed mucin containing; correlation resected specimens identified several cystadenoma. 20,30 Imaging classification also suffered lack uniform lesions. Specifically, there (no individual being > 2 cm diameter) morphology, unlike "classic" glycogen-rich described This misclassification critical ability predict nature mass; accuracies range from 20% 60%. 28,32,40 results insufficient preclude surgical exploration symptomatic cases. In incidentally discovered, recommendation surgery follow-up clearly defined. Another group included category "cystic masses" arise duct system. confuses understanding relatively uncommon intraductal associated hypersecretion; papillary reported. 1 authorities refer tumors. On studies, focal diffuse dilatation any system recognized. scans images excellent tests detection high changes must regarded frank neoplasms. Intraductal tumor (IPMT) first endoscopic retrograde cholangiopancreatography (ERCP) main marked hypersecretion produces characteristic findings. 25 As became more fully understood, four variants described: (1) segmental (2) involvement duct, (3) (4) branch duct. 31 Careful analysis reveals along ducts hyperplasia dysplasia, carcinoma situ, carcinoma. fact, present single lesion. Because predictable histology, most advocate resection when discovered. imaging, IPMT variety appearances. Itai et al distinguished between hypersecreting 12 ectasia (lesions arising ducts). 14 Since original descriptions, multiple reviews published. 3,18,29,31,33,36 key finding author's experience, common. They usually visualized uncinate process gland, although occur throughout gland multiple. Once visualized, ERCP indicated establish mucin. experience increased lesions, (MRCP) widely used. Advocates MRCP state technique sensitive filling side obscured plugs. 27,38,39 cases detected incidental undergoing other indications. small therefore, management implications. investigators suggest immediate resection. 6,18,33 Nagai 21 reviewed material 29 found rough size their larger commonly malignant. postulate an adenoma–carcinoma sequence Kimura 15,16 250 elderly low malignancy study serial ERCPs nine patients, mean 30 months, Obara 24 remain unchanged, whereas progress. institution, staff extended 3 144 months (mean follow-up, 28 months). 9 cases, pathologic cytologic proof (Figs. 3–5); imaging. Seventeen process. Almost (those 5 adopt following protocol patients: All suspected potential candidates. If patient discovered 2.5 diameter, confined ducts, displays no solid then offered option follow-up. follows at 6 8- 13-month intervals unless change symptoms. perceptible growth immediately resected. Differential pancreas include pseudocyst, islet cell tumor, periampullary diverticulum. common lesion, which confused neoplasm, pseudocyst chronic pancreatitis. Usually, appropriate history elicited; absence such history, identical. 7,35 Some advocated needle aspiration method definitively diagnosing masses. 11 Needle biopsy allows cytopathologic fluid, histochemical type, assay markers. 2,22,34