Solid and papillary epithelial neoplasm of the pancreas: CT and MR findings

Solid and papillary epithelial neoplasm of the pancreas is a very rare low-grade malignant neoplasm with only 126 cases reported in the literature and seen mostly in young female patients. Surgical excision means cure in cases before malignant degeneration developed. Its characteristic findings are typical location in the tail of the pancreas, peripheral capsule formation, hypodensity on CT images, and hyperintense internal signal characteristics on T1-weighted MR images secondary to hemorrhage and accumulation of methemoglobine molecule. These findings are enough for the preoperative diagnosis that may lead to early surgery and cure. We present the CT and MR findings of this very rare neoplasm in a case report.     

Solid and papillary epithelial neoplasm of the pancreas: MR imaging and pathologic correlation.

Correlation of magnetic resonance (MR) imaging findings and those at pathologic evaluation was attempted in six cases of solid and papillary epithelial neoplasm of the pancreas. All patients were female, and the mean patient age was 26 years (range, 13-73 years). On T1-weighted spin-echo images, tumors were well demarcated, and areas of high signal intensity were evident within them. At macroscopic examination, these areas corresponded to solid portions with marked hemorrhagic necrosis or cystic portions filled with hemorrhagic debris. In three of four masses surrounded by macroscopically evident fibrous capsules, a rim of low intensity was revealed at T1-weighted imaging. When T1-weighted spin-echo imaging reveals obvious areas of high intensity within a sharply marginated tumor of the pancreas, especially in a young woman, solid and papillary epithelial neoplasm might be a primary diagnostic consideration.     

Solid and papillary epithelial neoplasm of the pancreas. Radiographic, CT, sonographic, and angiographic features

Solid and papillary epithelial neoplasm of the pancreas is a nonfunctioning tumor seen a slowly enlarging upper abdominal mass in young women. It is usually large, well encapsulated, and undergoing necrotic degeneration. On ultrasound, it is sharply defined, nonhomogeneous, and lacking central enhancement. On angiography, it can be avascular or hypovascular depending on the degree of necrosis. Calcification has not been reported, and metastatic deposits are rare. Excision leads to an excellent prognosis.     

胰腺囊实性乳头状上皮性肿瘤的CT、MRI诊断

目的 研究胰腺囊实性乳头状上皮性肿瘤CT、MRI表现，提高对该病的认识诊断水平。方法 3例经手术病理证实的胰腺囊实性乳头状上皮性肿瘤均经CT检查，其中1例还进行MR平扫和动态增强。回顾性分析其临床特征及CT、MRI表现。结果 3例患者均为年轻女性，无黄疸。CT均表现为胰头部巨大的囊实性肿块；其中1例肿块内可见钙化；1例伴有胰管轻度扩张。所有3例肝内外胆管均未见扩张。1例MR检查的病例胰头部肿块在T1WI、T2WI上呈混杂信号。增强后，CT、MRI上肿块囊壁及实性成分均明显强化。结论 胰腺囊实性乳头状上皮性肿瘤CT、MRI表现较具特征性，结合临床特征可在术前作出诊断。     

Solid and papillary epithelial neoplasms of the pancreas: CT findings

Five female patients and one male patient with solid and papillary epithelial neoplasms of the pancreas were examined with computed tomography (CT). The mean age of the patients was 27 years (range, 13-46 years). All cases showed well-encapsulated, round or lobulated masses consisting of both cystic and solid areas. Cystic portions showed CT numbers that suggested hemorrhagic necrosis. There were no internal septations within the masses. In three tumors located in the head of the pancreas, dilatation of the biliary tree was absent or minimal, although the masses were large. Two tumors contained calcifications. One tumor demonstrated metastatic deposits in liver and lymph nodes. Metastatic masses appeared similar to the primary pancreatic mass. Solid and papillary neoplasm of the pancreas should be the primary diagnostic consideration when characteristic CT findings are detected in a young female patient.     

Solid and cystic papillary epithelial neoplasm of the pancreas in an 11-year-old girl: imaging features with pathological correlation

Solid and cystic papillary epithelial neoplasms (SCPEN) of the pancreas are rare tumours seen in young women. Pancreatic masses in children are extremely rare and SCPEN should be considered in the radiological differential diagnosis. Although there have been many series of SCPEN reported in the published literature in adults, only two series have focused on paediatric patients. The radiological and histopathological features of SCPEN in a paediatric patient are presented.     

胰头部囊实性乳头状上皮性肿瘤1例

患者 女性，20岁。无意中发现右上腹肿块1年余，伴右上腹及要背部隐痛半年。近2天来由于有轻度恶心、呕吐而入院，呕吐为非喷射性，呕吐物为胃内容物，无明显外伤史。体检：皮肤巩膜无黄染，浅表淋巴结无肿大；肌腹紧张，右上腹压痛明显，可触及约10．0cm×10．0cm大小的包块。边缘清，质韧，固定无明显活动。B超：腹腔内胰头区混合性肿块。[第一段]     

胰腺导管内乳头状黏液性肿瘤的影像学进展

胰腺导管内乳头状黏液性肿瘤(IPMNs)是胰腺最常见的囊性肿瘤[1].1982年由Ohhashi首次报道,定义为一种胰腺产生黏液的肿瘤[2].以后陆续有文献对该肿瘤进行不同的命名,如:产黏液癌、高分泌黏液癌、导管内乳头状肿瘤等.     

Intraductal papillary mucinous neoplasm of the pancreas: differentiate from chronic pancreatits by MR imaging

Purpose

To evaluate the differentiating factors for intraductal papillary mucinous neoplasm of the pancreas and chronic pancreatitis as determined by MR imaging.

Materials and methods

During a three-year period, we performed MR imaging on 33, consecutive patients with IPMN and on 41 patients with chronic pancreatitis. All IPMNs were confirmed by surgery. Two radiologists retrospectively analyzed the ductal change, the cyst shape, CBD dilatation, lymphadenopathy, and parenchymal change. The sensitivity and specificity were calculated for each MRI findings using the Chi square test. Statistically significant MR findings were further analyzed using multivariate logistic regression analysis. The diagnostic performance was evaluated according to the area under the receiver operating characteristic curve (A_z) using specific MRI findings. Simple κ statistics were used to evaluate the inter-observer reliability.

Results

Statistically specific findings for IPMN compared with those for chronic pancreatitis, were duct dilatation without stricture (specificity = 95.1%, sensitivity = 75.8%, p < 0.0001), bulging ampulla (specificity = 97.6%, sensitivity = 30.3%, p < 0.0001), nodule in a duct (specificity = 100%, sensitivity = 15.2%, p < 0.0004), grape-like cyst shape (specificity = 97.6%, sensitivity = 78.8%, p < 0.0001), and nodule in a cyst (specificity = 100%, sensitivity = 24.2%, p < 0.0001). Statistically specific findings for chronic pancreatitis compared with those for IPMN, were duct dilatation with strictures (specificity = 93.9%, sensitivity = 95.1%, p < 0.0001), the presence of a stone (specificity = 97.0%, sensitivity = 56.1%, p < 0.0001), and a unilocular cyst shape (specificity = 93.9%, sensitivity = 34.1%, p < 0.0004). Duct dilatation without stricture and a grape-like cyst shape were independently associated with the IPMN. Duct dilatation with strictures was independently associated with the chronic pancreatitis. Interobserver agreement was good to excellent for each finding (κ = 0.762–1.000).

Conclusion

Highly specific findings for IPMN include duct dilatation without stricture, bulging ampulla, nodule in a duct, grape-like cyst shape, and nodule in a cyst. MRI is very useful for differentiating IPMN from chronic pancreatitis using these specific findings.     

多层CT评估胰腺导管内乳头状黏液瘤的侵袭性

目的对用多层CT了解胰腺导管内乳头状黏液瘤(intraductal papillary mucinous neoplasm,IPMN)有无侵袭性的价值进行评价。材料与方法本研究得到医学伦理委员会     

Malignant intraductal papillary mucinous neoplasm of the pancreas: in situ versus invasive carcinoma surgical resectability

PURPOSE: To retrospectively evaluate computed tomographic (CT) findings in patients with in situ and invasive malignant intraductal papillary mucinous neoplasms (IPMNs) of the pancreas and to evaluate the accuracy for surgical resectability, with surgery and pathologic analysis as the reference standards. MATERIALS AND METHODS: Institutional review board approval was obtained, and the informed consent requirement was waived. Forty-six patients with malignant IPMN proved at pathologic examination of the surgically resected specimen (n = 44) or laparotomy (n = 2) underwent surgery after multidetector CT was performed. CT findings were retrospectively evaluated to determine if a pancreatic malignant IPMN tumor was present; to make this determination, CT criteria were used to differentiate in situ from invasive tumors and signs of unresectability (liver metastasis, vascular CT pattern of encasement, or regional lymph node metastasis). The extent of the vascular CT pattern of encasement was recorded for each patient (no obliteration of the fat plane, obliteration of the fat plane of <50%, or obliteration of the fat plane of > or =50%). Statistical analysis was performed with the chi(2) and Student t tests. RESULTS: CT revealed a mural nodule in the pancreatic duct wall in 14 patients with in situ carcinoma and one patient with invasive carcinoma (P < .003). CT revealed an infiltrative pancreatic mass in 17 patients with invasive carcinoma and two patients with in situ carcinoma (P < .02). Of the mural nodules, 93% were seen in patients with in situ carcinoma, whereas 90% of infiltrative pancreatic masses were observed in patients with invasive carcinomas. The positive predictive value of CT for determining resectability was 100%, and the overall accuracy of CT for determining resectability and unresectability was 74%. The positive predictive value of CT for determining unresectability was 17%, mainly owing to overestimation of arterial invasion. CONCLUSION: CT is helpful in the differentiation of in situ and invasive IPMN. Classic vascular invasion criteria lead to the overestimation of surgical tumor unresectability in patients with malignant IPMN.     

MDCT of intraductal papillary mucinous neoplasm of the pancreas: evaluation of features predictive of invasive carcinoma

OBJECTIVE: The purpose of our study was to evaluate factors predictive of the presence of invasive carcinoma associated with intraductal papillary mucinous neoplasm (IPMN) of the pancreas on MDCT. MATERIALS AND METHODS: Preoperative MDCT of 36 consecutive patients (23 men, 13 women; mean age, 66.6 years) who had undergone surgical resection and had a pathologic diagnosis of IPMN were retrospectively assessed. CT was performed with a 4-MDCT scanner with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Arterial and venous phase images were acquired at 25 and 50-60 sec from the start of IV contrast administration. Type of ductal involvement, location, tumor size in branch duct type and combined type lesions, caliber of the main pancreatic duct, caliber of the common bile duct or common hepatic duct, and solid appearance of the lesion were assessed on CT and correlated with pathologic findings for invasive carcinoma. RESULTS: Pathologic analysis revealed carcinoma in situ in seven patients (19%) and invasive carcinoma in 15 patients (42%) arising from the IPMN. With invasive carcinoma, the size of the tumor in branch duct type and combined type, and the caliber of the main pancreatic duct were significantly larger compared with the lesions without invasive carcinoma (4.7 +/- 1.7 cm vs 2.6 +/- 1.4 cm [p = 0.0007] and 9.3 +/- 5.5 mm vs 4.6 +/- 4.1 mm [p = 0.006], respectively). A solid mass (p < 0.001), dilatation of the common bile duct or common hepatic duct (> or = 15 mm), and the presence of a stent (p = 0.0004) were correlated with the presence of associated invasive carcinoma. CONCLUSION: MDCT helped to predict invasive carcinoma associated with IPMN.     

Magnetic resonance pancreatography: comparison of two- and three-dimensional sequences for assessment of intraductal papillary mucinous neoplasm of the pancreas

The purpose was to compare two-dimensional (2D) magnetic resonance pancreatography (MRP) with 3D MRP to evaluate intraductal papillary mucinous neoplasm (IPMN). Thirty-four patients (22 men, 12 women; age range, 45–80 years) with IPMN (n = 40) were examined with MRP on 2D and 3D sequences. Two readers independently reviewed the images to assess the overall image quality, artifacts, lesion location, communication with main pancreatic duct, and potential for malignancy. The readers assigned their confidence level (1–5) for predicting ductal communication of the lesion. The results of MRP were compared with endoscopic retrograde pancreatography and surgical and histopathologic findings. Studies obtained with 3D MRP were of significantly higher technical quality than those obtained with 2D MRP. Although 3D MRP showed higher area under the ROC curve (Az) values for predicting ductal communication of the lesion, there was no statistical significance between Az values of 2D and 3D MRP (Az for 2D = 0.821, 0.864 for readers 1 and 2, respectively, and Az for 3D= 0.964, 0.921). Accuracies for discriminating benign from malignant lesions were 70 and 67.5% (reader 1 and 2, respectively, for 2D) and 62.5 and 80.1% (3D). 3D MRP showed superior image quality to that of 2D MRP but did not increase the diagnostic accuracy for predicting ductal communication of the lesion.     

Intraductal papillary mucinous neoplasm of pancreas: multi-detector row CT with 2D curved reformations--correlation with MRCP

PURPOSE: To retrospectively compare accuracy of multi-detector row computed tomography (CT), combined with two-dimensional (2D) curved reformations, and that of magnetic resonance (MR) cholangiopancreatography (MRCP) for characterization of intraductal papillary mucinous neoplasm (IPMN) as malignant, with pathologic examination as reference standard. MATERIALS AND METHODS: Institutional review board approval was obtained, informed consent was waived, and study was HIPAA compliant. Twenty-five patients (12 women, 13 men; age range, 44-88 years) with pathologically proved IPMN were examined with dual-phase CT with 1.25-mm-thick sections for pancreatic phase; 2D curved reformations along main pancreatic duct (MPD) were generated. T2-weighted MRCP included thick- and thin-slab single-shot fast spin-echo imaging and transverse fast spin-echo imaging. Two radiologists, blinded to surgical and pathologic findings, evaluated images for lesion location, septa, mural nodules, communication with MPD, extent and diameter of MPD dilatation, calcifications, and vascular encasement. Malignancy was suspected when one of the following was present: MPD diameter larger than 10 mm, mural nodules, vascular encasement, peripancreatic lymphadenopathy, or metastases. Sensitivity and specificity values for prediction of malignancy were calculated for CT and MRCP. Interobserver variability was determined (kappa analysis). RESULTS: Excellent correlation between modalities was observed. Cyst communication was seen in 20 and 21 of 24 branch pancreatic duct (BPD) IPMNs with CT and MRCP, respectively. Sensitivity, specificity, and accuracy for detection of malignancy were 70%, 87%, and 76% (CT) and 70%, 92%, and 80% (MRCP), respectively. Interobserver agreement was good to perfect for both readers in all comparisons (overall, kappa = 0.70-1.00). CONCLUSION: CT combined with 2D curved reformation can provide imaging details of IPMN, including communication of BPD IPMN with MPD, that are almost equivalent to those provided at MRCP. Presence of mural nodules, dilated MPD (>10-mm diameter), or thick septa at CT or MRCP may be used as independent predictors of malignancy.