Mucin-producing neoplasms of the pancreas. Intraductal papillary and mucinous cystic neoplasms.

OBJECTIVE: The authors compared the clinicopathologic features of the intraductal papillary and mucinous cystic neoplasms of the pancreas and clarified the similarities as well as the differences between these two tumors. In addition, they reviewed 104 cases of the intraductal papillary neoplasm in the English literature to provide a global view of the condition. SUMMARY BACKGROUND DATA: Controversy about the term and clinicopathologic entity still exist regarding intraductal papillary neoplasm of the pancreas. Currently, with only a few cases of this rare tumor in each report, there continues to be inadequate knowledge available regarding the tumor and methods by which to distinguish it from the mucinous cystic neoplasm. METHODS: Multiple demographic and clinicopathologic parameters were compared between intraductal papillary and mucinous cystic neoplasms identified from 1985 to 1994 in the Medical Center, Veterans General Hospital--Taipei. RESULTS: There were four intraductal papillary adenocarcinomas and 10 mucinous cystic neoplasms (8 cystadenocarcinoma and 2 cystadenoma). The sex, age, size, tumor location, and pathologic findings were quite different between these two groups. Clinical presentation of intraductal papillary adenocarcinomas were similar to those of periampullary tumors. The most common presentations of mucinous cystic neoplasm were epigastric pain and abdominal mass. All four intraductal papillary adenocarcinoma showed mucin secretion from a patulous orifice of the ampulla of Vater and filling defects in the dilated main pancreatic duct by endoscopic retrograde cholangiopancreatography (ERCP). Accurate preoperative diagnosis was not easy regarding either group. Serum carbohydrate antigen 19-9 (CA 19-9) was more useful for diagnosis in both groups. CONCLUSIONS: The intraductal papillary neoplasm is a unique clinical entity but not a variant of mucinous cystic neoplasm in terms of sex, age, size, tumor location, or pathologic picture. The pathognomonic findings of ERCP should lead to diagnosis. Very aggressive surgical procedures should be attempted for these two mucin-producing neoplasms with low-grade malignancy.     

Cystic pancreas neoplasias

For the treatment of cystic changes of the pancreas, it is essential to distinguish cysts and pseudocysts from neoplasm. Since clinical parameters are usually not characteristic, only morphologic analysis will prove a diagnosis. Nowadays, the cystic pancreatic neoplasms are described as: microcystic adenoma (rich-in-glycogene cystadenoma), and mucinous cystic neoplasms (cystadenocarcinoma or cystadenoma). Morphology, etiology, clinical findings, and treatment are discussed on 3 cases. The new classification of cystic pancreatic neoplasms is important for prognosis in two aspects: 1) On the clinical finding of a pseudocyst, every surgeon should think of a mucinous cystic neoplasm and look for solid tumours digitally. 2) For the pathologist, any mucinous neoplasm should cause him to analyse such cysts macroscopically and, if possible, also microscopically, to rule out an adenocarcinoma.     

Outcome of duodenum-preserving resection of the head of the pancreas for intraductal papillary-mucinous neoplasm

BACKGROUND: The standard surgical procedure for intraductal papillary-mucinous neoplasm of the pancreatic head is pylorus-preserving pancreatoduodenectomy. A less extensive resection may be justified because most intraductal papillary-mucinous neoplasms are benign or of low-grade malignancy. AIMS AND METHODS: The outcome of duodenum-preserving pancreatic head resection with preservation of the main bile duct was evaluated retrospectively in 13 patients with a branch-type intraductal papillary-mucinous neoplasm in the head of the pancreas and with a median (range) follow-up of 60.0 (0.3-99.5) months. RESULTS: Post-operative complications included anastomotic leakage (n=3), bile duct perforation (n=1), intra-abdominal bleeding (n=3), delayed gastric emptying (n=2) and death (n=2). All the resection margins were clear of tumour on histological examination. Ten of 11 patients maintained over 90% of their pre-operative body weight. Glucose tolerance improved in 4 of 11 evaluable patients, was unchanged in 6 and worsened in 1 patient. Biliary scintigraphy showed that bile flow was delayed compared with that before surgery (8.8 +/- 1.1 vs. 19.6 +/- 4.6 min; p = 0.03). Neither recurrence nor metastasis was observed. CONCLUSION: The results of duodenum-preserving pancreatic head resection for branch duct-type intraductal papillary-mucinous neoplasm were satisfactory and provided a good quality of life.     

The mucin profile of noninvasive and invasive mucinous cystic neoplasms of the pancreas

Recently, it was shown that ductal adenocarcinomas and intraductal papillary-mucinous neoplasms of the pancreas differ in their expression of the mucin markers MUC1 and MUC2 while both tumors express MUC5AC. It is not known whether mucinous cystic neoplasms of the pancreas have their own mucin profile. To clarify this issue, 22 mucinous cystic neoplasms were examined immunohistologically for their expression of MUC1, MUC2, MUC5AC, and MUC6 and also for the protein products of the tumor suppressor genes p53 and DPC4 and the mismatch repair genes. Noninvasive mucinous cystic neoplasms, regardless of the degree of cellular atypia, were all positive for MUC5AC and negative for MUC1, with the exception of the cyst-lining epithelium of a single case with eosinophilic cytology (case no. 16). Only in cases with an invasive component was MUC1 expression observed. MUC2 expression was restricted to goblet cells scattered within the epithelium of the mucinous cystic neoplasms and was often accompanied by endocrine cells, a further indication of intestinal differentiation. DPC4 expression was maintained in all tumors, except for three invasive carcinomas. p53 nuclear reactivity was found in one borderline tumor and four invasive mucinous cystic carcinomas. The results suggest that the epithelium of noninvasive mucinous cystic neoplasms does not differ in its expression of MUC5AC from ductal adenocarcinomas, intraductal papillary-mucinous neoplasms, and metaplastic pancreatic duct epithelium. The fact that noninvasive mucinous cystic neoplasms lack MUC1 expression (except for an eosinophilic variant) but express it when they become invasive might be used as a marker indicating the step of progression from noninvasiveness to invasiveness.     

Pathologic examination accurately predicts prognosis in mucinous cystic neoplasms of the pancreas.

The behavior of pancreatic mucinous cystic neoplasms has long been debated. Some authors contend that histologically benign neoplasms can recur and metastasize. We reviewed the gross and microscopic findings and outcomes of 61 mucinous cystic neoplasms diagnosed at The Johns Hopkins Hospital from March 20, 1984 to July 8, 1998. Each neoplasm was placed into one of four categories based on complete histologic examination: invasive mucinous cystadenocarcinoma, mucinous cystic neoplasm with in situ carcinoma, borderline mucinous cystic neoplasm, and mucinous cystadenoma. Neoplasms in the latter three categories were included only if they were entirely resected and completely examined. Patient outcomes were obtained from hospital records and patient and physician follow-up. Twenty (33%) of the patients had invasive mucinous cystadenocarcinomas, and they had 2- and 5-year disease-specific survival rates of 67% and 33% (mean follow-up of survivors, 4.2 years), respectively. Nine (15%) patients had mucinous cystic neoplasms with in situ carcinoma (mean follow-up of survivors, 4.1 years). Five (8.2%) patients had borderline mucinous cystic neoplasms (mean follow-up of survivors, 5.6 years). Twenty-seven (44%) patients had mucinous cystadenomas (mean follow-up of survivors, 5.1 years). No mucinous cystadenoma, borderline mucinous cystic neoplasm, or mucinous cystic neoplasm with in situ carcinoma recurred or metastasized. No patient with the diagnosis of mucinous cystadenoma, borderline mucinous cystic neoplasm, or mucinous cystic neoplasm with in situ carcinoma died of disease. The difference in disease-specific survival rates between patients with invasive mucinous cystadenocarcinomas and those with noninvasive tumors was significant (p < 0.0001, log-rank test). One case, originally showing only benign histology on incisional biopsy, contained foci of invasive carcinoma on complete resection. Completely resected and entirely examined mucinous cystadenomas, borderline mucinous cystic neoplasms, and mucinous cystic neoplasms with in situ carcinoma follow benign courses. Because invasive carcinoma can be focal, failure to study an entire mucinous cystic neoplasm may result in the miscategorization of a malignant neoplasm as benign.     

Management of intraductal papillary mucinous tumours of the pancreas.

OBJECTIVE: To focus attention on the management and outcome of patients with intraductal papillary mucinous tumours of the pancreas. DESIGN: Retrospective study and analysis of published reports. SETTING: University hospital, France. SUBJECTS: 111 patients (101 published cases and our own 10 cases) divided in two groups: the first including malignant tumours (n = 46), and the second group benign or in situ tumours (n = 61). In 4 patients the type of tumour was not known. MAIN OUTCOME MEASURE: Resectability, mortality and recurrence. RESULTS: More men had benign or in situ tumours [48/61 (79%) compared with 28/46 (61%), p = 0.054]. Pancreatitis was more common among benign than malignant tumours [34/61 (58%) compared with 21/46 (46%), p = 0.33]. In group I, 39 patients had diabetes. A total of 107 patients were operated on: pancreaticoduodenectomy (n = 54, 50%), distal pancreatectomy (n = 25, 23%), total pancreatectomy (n = 4,4%), bypass (n = 2,2%). The type of resection was not mentioned in 22 records (21%). Four patients were not operated on because of their poor general condition. The resectability rate was 98% (105/107). Eleven patients had died at the time of publication. Hospital mortality rate was 3% (n = 3), mainly because 2 of the 4 who had total pancreatectomy died. With a median follow-up of 37 months, recurrence was 5% (n = 5). CONCLUSION: Intraductal papillary mucinous tumours of the pancreas are well known distinctive pancreatic tumours that are usually intraductal but may develop into invasive carcinoma. They should be resected, and have a good prognosis and low recurrence rate.     

Cystic neoplasms of the pancreas

As the use of cross-sectional imaging has become more frequent, there has been an increase in the diagnosis of cystic neoplasms and small non-functioning neuroendocrine neoplasms within the pancreas. Investigation and follow-up of cystic lesions of the pancreas requires a multimodal approach, of which endoscopic ultrasound with biopsy is becoming an increasingly important component. The main premalignant cystic neoplasms of the pancreas are mucinous-type tumours, intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm (MCN). Main-duct IPMN should be resected due to the high incidence of underlying malignancy; however, a selective approach to intervention for side-branch IPMN should be taken (dependent on the presence of symptoms, tumour markers and tumour characteristics). Pancreatic neuroendocrine neoplasms (PanNENs) can also present as cystic lesions in approximately 18% of cases. Biochemically confirmed functional PanNEN and non-secreting PanNENs larger than 2 cm in size should be evaluated for surgery.     

The immunohistochemical mucin expression pattern distinguishes different types of intraductal papillary mucinous neoplasms of the pancreas and determines their relationship to mucinous noncystic carcinoma and ductal adenocarcinoma.

Intraductal papillary-mucinous neoplasms of the pancreas seem to comprise various types, whose relationship to ductal adenocarcinoma and mucinous noncystic carcinoma is unclear. We analyzed the mucin immunophenotype and the DPC4/SMAD4 expression in intraductal papillary-mucinous neoplasms, ductal carcinomas, and mucinous noncystic carcinomas to define features that may help to distinguish between different types of intraductal papillary-mucinous neoplasms and to establish their relationship to other neoplasms of the exocrine pancreas. A series of 51 intraductal papillary-mucinous neoplasms, three mucinous noncystic carcinomas (two with an intraductal component), and 35 ductal adenocarcinomas were screened immunohistochemically for their expression of MUC1, MUC2, MUC5, and DPC4/SMAD4. All intraductal papillary-mucinous neoplasms and mucinous noncystic carcinomas were positive for MUC5. Thirty-two intraductal papillary-mucinous neoplasms and three mucinous noncystic carcinomas abundantly expressed MUC2 but no (or only little) MUC1. The remaining intraductal papillary-mucinous neoplasms showed either mainly MUC1 expression or focal MUC1 and MUC2 expression. All ductal carcinomas but one were MUC2 negative and MUC1 and MUC5 positive. DPC4 was not expressed in two intraductal papillary-mucinous neoplasms that showed a tubular invasion pattern. Twelve of 23 ductal adenocarcinomas were DPC4 positive. Intraductal papillary-mucinous neoplasms can be divided into at least three different mucin immunophenotypes. The first and largest group of intraductal papillary-mucinous neoplasms and mucinous noncystic carcinomas is MUC1 negative and MUC2 positive and probably forms one tumor entity. The second group seems to be related to ductal carcinoma because of its MUC1 positivity in the absence or very weak MUC2 staining. The third group shows focal MUC1/MUC2 expression and is characterized by oncocytic histology.     

Cystic tumours of the pancreas: diagnostic accuracy, pathologic observations and surgical consequences

Background: Cystic neoplasms of the pancreas account for only 1% of primary pancreatic lesions. However, patients with these tumors are diagnosed more frequently. Up to now, nonsurgical management is still the established form of treatment of benign cystic tumours of the pancreas. Methods: Between 1987 and 1996 we treated 51 patients with serous and mucinous cystadenoma and their malignant counterparts, serous and mucinous cystadenocarcinoma. Results: Eighty-five percent of the patients presented symptoms. Computed tomography and endoscopic cholangiopancreatography (ERCP) were the most sensitive diagnostic techniques; however, in three patients with serous cystadenoma and in one patient with serous cystadenocarcinoma, ERCP findings were completely normal. The tumour was resected in all but one patient. There was no perioperative mortality. After dismissal from the hospital, all patients in whom benign tumours had been resected are still alive; however, the late mortality of mucinous cystadenocarcinoma was 36% after a median follow-up of 6 years. Conclusion: Surgical resection is recommended in all cystic tumours, even in serous cystic tumours, because symptoms may develop and malignant transformation to serous cystadenocarcinoma is possible. Received: 6 November 1997     

Intraductal papillary mucinous tumors and mucinous cystic tumors of the pancreas: imaging

Most cystic lesions of the pancreas are nonneoplastic and inflammatory in nature. However, approximately 5%–15% of cystic pancreatic masses may be neoplastic. Among the cystic neoplasms are the mucin-producing tumors, both the intraductal papillary mucinous neoplasms and the mucinous cystic neoplasms. Their imaging features on contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) can assist in the differentiation of these lesions. The imaging findings of both intraductal papillary mucinous neoplasm and mucinous cystic neoplasm are reviewed with attention to CT and MRI.     

Systematic review of the utility of 18-FDG PET in the preoperative evaluation of IPMNs and cystic lesions of the pancreas

BackgroundThe aim of this systematic review is to assess the role of 18-fluorodeoxyglucose positron emission tomography in the preoperative evaluation of intraductal papillary mucinous neoplasms and cystic lesions of the pancreas.MethodsA computerized PubMed search was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify studies evaluating positron emission tomography in the preoperative evaluation of pancreatic cystic lesions.ResultsA total of 14 studies evaluated the role of 18-fluorodeoxyglucose positron emission tomography/positron emission tomography-computed tomography, 9 of which evaluated only intraductal papillary mucinous neoplasms and 5 evaluated all pancreatic cystic lesions, including intraductal papillary mucinous neoplasms. Pooled analysis was carried out for studies evaluating intraductal papillary mucinous neoplasms only and studies evaluating all cystic lesions. Imaging with 18-fluorodeoxyblucose positron emission tomography had a positive predictive value, negative predictive value, sensitivity, specificity, and accuracy of 90%, 91%, 85%, 95%, and 91% in identifying malignancy (defined as either invasive and/or high-grade dysplasia) in intraductal papillary mucinous neoplasms and a positive predictive value, negative predictive value, sensitivity, specificity, and accuracy of 85%, 81%, 79%, 86%, and 88% in identifying malignancy in other cystic lesions. Pooled analysis reported the positive predictive value, negative predictive value, sensitivity, specificity, and accuracy of Sendai consensus guidelines (SCG) criteria as 69%, 69%, 68%, 55%, and 58%. The Fukuoka consensus guidelines (FCG) only had sensitivity, specificity, and accuracy reported as 61%, 52%, and 52%, respectively.ConclusionThe 18-fluorodeoxyblucose positron emission tomography had a high degree of accuracy of detecting malignancy in intraductal papillary mucinous neoplasm and cystic lesion of the pancreas. Comparison of the utility of positron emission tomography with the Fukuoka consensus guidelines and the Sendai consensus guidelines suggest that positron emission tomography is superior to present guidelines in detecting malignant intraductal papillary mucinous neoplasm and cystic lesion of the pancreas. Further studies in larger patient cohorts may be required to corroborate these findings and to determine the place of positron emission tomography in the management of intraductal papillary mucinous neoplasm and cystic lesions of the pancreas.     

Intraductal papillary mucinous tumors of the pancreas

BACKGROUND: An increasing number of intraductal papillary mucinous tumors of the pancreas have been reported in recent years. The indolent character and favorable prognosis of this neoplasm have been described. METHODS: Intraductal papillary mucinous tumors were classified into main duct type (n = 8) and branch type (n = 28) according to the dominant location of the tumor. This single-institute study examined the clinicopathological features and outcome after surgical resection in patients with intraductal papillary mucinous tumors. RESULTS: The gender, age, tumor size, and prognosis were quite similar for the main duct type and branch type groups. Branch type tumors were more frequently located in the head of the pancreas than were main duct type tumors. Histological examination revealed that 88% of main duct type tumors were adenocarcinomas; however, only 46% of branch type tumors were adenocarcinomas. Five-year survival rates for the patients with all main duct type tumors (n = 8), main duct type adenocarcinoma (n = 7), all branch type tumors (n = 28), and branch duct adenocarcinoma (n = 13) were 100%, 100%, 90.6%, and 90.9%, respectively. CONCLUSIONS: Intraductal papillary mucinous tumors had a favorable prognosis after surgical treatment. A curative pancreatectomy should be indicated for this localized malignant tumor.     

Cystic tumors of the pancreas: diagnosis, management and results

Pancreatic cystic tumours are rare and less frequent than other pancreatic tumours. In recent decades, these tumours are being diagnosed with increasing frequency due to the extensive availability of, and improvement in, modern imaging techniques and it is often possible not only to differentiate them preoperatively from other cystic pancreatic disorders but also from one another. Pancreatic cystic tumours comprise a variety of neoplasms with a wide range of malignant potential: serous cystic tumours are benign, whereas mucinous cystic tumours, and intraductal papillary mucinous tumours are considered premalignant, while solid pseudopapillary tumours have a non-aggressive behaviour in the vast majority of cases. Most patients have no symptoms; and when clinical signs are present, they never help us to identify the type of pathology. Serous cystic neoplasms usually do not mandate resection unless the lesion is symptomatic. Mucinous cystic neoplasms and intraductal papillary mucinous neoplasms have a premalignant or malignant tendency, and therefore need to be managed aggressively by pancreatic resection. Their prognosis is excellent in the absence of invasive disease, but the presence of invasive malignancy is associated with a poor prognosis. This review addresses the symptoms, diagnosis, management and prognosis of this group of tumours.     

胰腺囊性肿瘤40例诊疗分析

目的探讨胰腺囊性肿瘤的诊治方法。方法对笔者所在医院科室2001年10月至2013年10月期间收治的40例胰腺囊性肿瘤患者的临床资料进行回顾性分析。结果胰腺囊性肿瘤无特殊临床表现,B超和CT检查对胰腺囊性肿瘤的诊断正确率分别为57．5％（23／40）和72．5％（29／40）,但不能准确区分其组织学类型。40例患者均行手术治疗,其中2例患者误诊为假性囊肿而行内引流术,另外38例行胰体尾切除术。术后病理学检查证实浆液性囊腺瘤23例,黏液性囊腺瘤9例,导管内乳头状黏液性腺瘤3例,黏液性囊腺癌5例。5例失访,35例患者获随访,随访时间为（74．2±12．8）个月（2个月～8年）;3例囊腺癌患者中1例肿瘤切除者至今存活（已随访8年）,2例肿瘤未切除者分别于术后4个月和7个月因肿瘤转移死亡;其余32例获访的囊腺瘤患者均存活至今。结论外科切除是治疗胰腺囊性肿瘤最有效的手段,即使是对于无任何症状的患者也应行积极的手术治疗。     

Les cystadénocarcinomes pancréatiques sont-ils des cystadénomes mucineux dégénérés?

Objectives of the studyTo define arguments in agreement or disagreement with the generally accepted theory of transformation from benign mucinous cystadenoma (MC) to malignant cystadenocarcinoma (CC) of the pancreas.MethodsA review of the literature since 1978 was conducted together with a comparative analysis of a multicentre retrospective study of the different mucinous cystic tumours of the pancreas: 150 MC, 79 CC and 55 intraductal papillary mucinous tumours of the pancreas (TIPMP). Multiple epidemiological and clinicopathological data were compared between MC and CC: mean age at diagnosis, sex distribution, association with diabetes or concurrent cancer, tumour location and size, type of pancreatic main duct communication, pancreatic fibrosis and serum CA 19-9 levels. The analysis concerned also histopathological features of resected cystadenocarcinomas (n = 58).ResultsTwo features suggested malignant transformation of mucinous cystadenomas: older mean age at diagnosis of CC and histological characteristics revealing areas of benign-appearing epithelium associated with areas of invasive carcinoma in 55% of cases. Conversely, two statistically significant discordant features were observed: a higher proportion of men (40% for CC vs 13% for MC) and a more frequent location in the head of the pancreas (49% vs 27%). The other differences were not in contradiction with the malignant transformation of MC: associated diabetes mellitus, increasing serum CA 19-9 levels and chromosomal aberrations were more frequent in CC. TIPMP were predominant in men (67%), and more common in the head of the pancreas (67%).ConclusionThe risk of malignant transformation of MC should not be questioned, despite sex distribution and location differences between MC and CC. These differences may be due to inaccurate designation of intraductal mucinous carcinomas as communicating CC or of CC as pancreatic mucinous adenocarcinomas.     

胰腺囊性肿瘤26例临床诊治分析

目的探讨胰腺囊性肿瘤的诊断和治疗。方法对2000年6月至2005年6月复旦大学附属中山医院收治的26例胰腺囊性肿瘤的临床资料进行回顾性分析。结果B超和CT对胰腺囊性肿瘤的诊断正确率分别为88%(23/26)和92%(24/26),但不能准确区分其组织类型。26例均行手术治疗并获随访,1例黏液性囊腺癌病人因复发转移于术后11个月死亡,其余均存活,无复发。结论伴有症状的胰腺浆液性囊腺瘤,以及黏液性囊性肿瘤及导管内乳头状黏液性肿瘤因有恶变倾向及临床不能鉴别其良恶性,需手术治疗;而无症状的浆液性囊腺瘤可观察随访。胰腺囊腺瘤手术切除后可获治愈,囊腺癌术后疗效也较满意。     

Mucinous cystic neoplasms of the pancreas: pathology and molecular genetics

Mucinous cystic neoplasm (MCN) of the pancreas is a distinct clinicopathological entity characterized by mucin-producing epithelial and cyst-forming neoplasm with “ovarian-type” stroma beneath the epithelial component. It is clearly distinguished from ductal adenocarcinoma and intraductal papillary mucinous neoplasm (IPMN). However, MCN can progress to infiltrating carcinoma, and frequently shows a similar histological pattern to ductal adenocarcinoma. Several genetic alterations such as K-ras oncogene mutation, and epigenetic alterations such as hypermethylation of p16 in the invasive component of MCN are also common with ductal adenocarcinoma. Furthermore, recent technologies, including a laser-assisted microdissection system for histological slides and global gene expression profilings using DNA microarrays, made possible to identify more information about molecular abnormalities of MCNs. It is important to diagnose the lesions before they progress to an invasive carcinoma. MCN is one of the precursors of invasive pancreatic carcinoma.     

Mucinous cystic tumors of the pancreas: clinicopathological features, prognosis, and relationship to other mucinous cystic tumors

The clinicopathological features of 56 patients with mucinous cystic tumors (MCTs) of the pancreas were studied. Particular attention was paid to the prognosis of MCTs and the relationship to their ovarian, hepatic, and retroperitoneal counterparts. To distinguish MCTs from pancreatic intraductal papillary-mucinous tumors, MCTs were defined as tumors lacking communication with the duct system and containing mucin-producing epithelium, usually supported by ovarian-like stroma. All 56 tumors occurred in women (mean age 48.2 years) and were preferentially (93%) located in the body and tail of the pancreas. In accordance with the WHO classification, MCTs were divided into adenomas (n = 22), borderline tumors (n= 12), and noninvasive and invasive carcinomas (n = 22). Survival analysis revealed the extent of invasion to be the most significant prognostic factor (p<0.0001). Malignancy correlated with multilocularity and presence of papillary projections or mural nodules, loss of ovarian-like stroma, and p53 immunoreactivity. Stromal luteinization with expression of tyrosine hydroxylase, calretinin, or alpha inhibin was found in 66% of the cases. We conclude that the biologic behavior of MCTs is predictable on the basis of the extent of invasion. The similarities (i.e. gender, morphology, stromal luteinization) between pancreatic MCT and its ovarian, hepatobiliary, and retroperitoneal counterparts suggest a common pathway for their development.     

Intraductal papillary-mucinous tumor of the pancreas: assessing the grade of malignancy from natural history

Intraductal papillary-mucinous tumor of the pancreas is a spectrum of conditions ranging from benign to malignant, and very few papers have referred to the natural history of this disease. In this communication the indicators of malignancy were examined from a viewpoint of natural history. Follow-up computed tomographies (CTs) more than 6 months after the diagnosis were reviewed in 17 Japanese patients with intraductal papillary-mucinous tumor of the pancreas. They were divided into two groups by the presence or absence of morphological progressive changes by the follow-up CTs, and the clinicopathological features were compared between the two groups to examine possible malignant indicators. The 17 patients consisted of seven patients in the no-change group and ten in the progressive group. The distribution of the patients was not different with regard to age; gender; or presence or absence of pancreatitis, diabetes mellitus, or unique findings of the ampulla of Vater between the two groups. The dilatation of the main pancreatic duct (> or = 3 mm) was more frequent in the progressive group: (eight of ten patients; 80%) than in the no-change group (two of seven patients; 29%) (P = 0.03). Six (86%) of the seven tumors in the no-change group were located in the branch duct, whereas five (50%) of the ten in the progressive group were situated in the main pancreatic duct. Histopathologic diagnoses of the resected specimens of the four in the no-change group examined were intraductal papillary-mucinous adenoma in three and adenoma with moderate dysplasia in one, whereas the diagnoses in the six in the progressive group examined were adenoma in two, adenoma with moderate dysplasia in two, and carcinoma (invasive) in two. The patients with intraductal papillary-mucinous tumor of the pancreas with a dilatation of the main pancreatic duct at the time of diagnosis should be followed up more carefully than those without dilatation. Once progressive morphological changes are detected by the follow-up CTs surgical resection should be considered because of possible malignancy.