Immunohistochemical analysis of molecular biological factors in intraductal papillary-mucinous tumors and mucinous cystic tumors of the pancreas

BACKGROUND: To investigate the malignancy and differentiation of intraductal papillary-mucinous tumors (IPMTs) and mucinous cystic tumors (MCTs) of the pancreas, clinicopathologic characteristics and immunohistochemical features were analyzed. METHODS: The clinicopathologic characteristics and immunohistochemical features of 24 patients with IPMT and 8 with MCT who underwent pancreatic resections at our hospital were examined. Immunohistochemical features analyzed included expression of p53 protein, proliferating cell nuclear antigen, integrins, interleukin-1 receptor type I, and hormone-associated receptors, and the factors correlated with malignancy were identified by multiple logistic regression. RESULTS: Among the IPMTs, there were 16 intraductal papillary adenomas, 5 intraductal papillary adenocarcinomas, and 3 moderate dysplasias. Among the MCTs, there were 6 mucinous cyst adenomas and 2 mucinous cyst adenocarcinomas. Multivariate analysis revealed that of the clinicopathologic characteristics, only the presence of mural nodules (odds ratio (OR) 7.12, P = 0.044) was independently correlated with the malignancy of IPMTs, and that of the immunohistochemical features, only alpha integrin subunit expression was independently correlated with malignancy of pancreatic mucinous tumors (OR 15.6, P = 0.036), especially IPMTs (OR 35.7, P = 0.012). CONCLUSION: These results indicate that alpha-containing integrin expression can be a significant marker of malignancy in pancreatic mucinous tumors.     

Immunohistochemical analysis of molecular biological factors in intraductal papillary-mucinous tumors and mucinous cystic tumors of the pancreas

Background: To investigate the malignancy and differentiation of intraductal papillary-mucinous tumors (IPMTs) and mucinous cystic tumors (MCTs) of the pancreas, clinicopathologic characteristics and immunohistochemical features were analyzed. Methods: The clinicopathologic characteristics and immunohistochemical features of 24 patients with IPMT and 8 with MCT who underwent pancreatic resections at our hospital were examined. Immunohistochemical features analyzed included expression of p53 protein, proliferating cell nuclear antigen, integrins, interleukin-1 receptor type I, and hormone-associated receptors, and the factors correlated with malignancy were identified by multiple logistic regression. Results: Among the IPMTs, there were 16 intraductal papillary adenomas, 5 intraductal papillary adenocarcinomas, and 3 moderate dysplasias. Among the MCTs, there were 6 mucinous cyst adenomas and 2 mucinous cyst adenocarcinomas. Multivariate analysis revealed that of the clinicopathologic characteristics, only the presence of mural nodules (odds ratio (OR) 7.12, P?=?0.044) was independently correlated with the malignancy of IPMTs, and that of the immunohistochemical features, only α[Formula: See Text] integrin subunit expression was independently correlated with malignancy of pancreatic mucinous tumors (OR 15.6, P?=?0.036), especially IPMTs (OR 35.7, P?=?0.012). Conclusion: These results indicate that α[Formula: See Text]-containing integrin expression can be a significant marker of malignancy in pancreatic mucinous tumors.     

不同病理类型的胰腺导管内乳头状黏液性肿瘤的临床特征

目的 总结不同病理类型胰腺导管内黏液性乳头状瘤(IPMT)的临床表现,提高对IPMT的诊治水平.方法 回顾分析1996年3月至2008年9月间经手术切除且病理证实的49例IPMT患者的临床表现、影像学特点及病理学特征,比较分析良性、交界性、恶性IPMT的临床表现.结果 49例IPMT患者中男27例,女22例,平均年龄(58±11)岁.良性19例,交界性9例,恶性21例.3类IPMT患者在性别、发病年龄、烟酒史、胰腺炎发作史、糖尿病病史,是否存在腹痛、腰背部放射痛、腹胀、腹泻、消瘦等症状,血CEA、AST、ALT水平,肿瘤位置及肿瘤分型上的差异均无明显统计学意义.但黄疸、术前CA19-9和碱性磷酸酶水平、肿瘤直径、主胰管直径、囊性肿瘤内是否存在隔膜、附壁结节的大小等方面的差异有统计学意义.恶性IPMT术后5年有1例病死,1例复发;交界性和良性IPMT有1例复发,1例因其他疾病病死.结论 不同病理类型的IPMT 临床特征存在一些差异,需综合判断进行鉴别.     

Intraductal papillary or mucinous tumors (IPMT) of the pancreas: report of a case series and review of the literature

OBJECTIVE: Despite a better understanding of these conditions, intraductal papillary or mucinous tumors (IPMT) of the pancreas still present difficulty relating to the predictive factors of malignancy and the risk of relapse after surgical resection. The aim of this study was to report on our experience and to compare it to previously published cases. METHODS: We studied retrospectively 26 patients (mean age 60.3 yr) presenting with IPMT. Of the 26 patients, 19 had surgical resection and seven did not. The main clinical feature was acute pancreatitis occurring in 38% of the patients. Segmental pancreatectomy was performed in all the cases. At pathological assessment of resection margins, tumor resection was considered as complete in 17 cases. Margins exhibited benign mucinous involvement, and resection was considered to be incomplete in one multifocal case and in one case with diffuse spread of the tumor. RESULTS: A total of 11 tumors were benign and five were malignant. Carcinomas were invasive in four cases (two invading the pancreatic parenchyma, one the duodenum, and one the peripancreatic nodes) and in situ in one case. Malignancy was not diagnosed preoperatively except when invasion was evident (duodenal spread). Although main pancreatic duct type and obstructive jaundice appeared as suggestive features for the risk of malignancy, no reliable preoperative predictive factors for malignancy could be identified as regarding to clinical parameters, biological examinations, carcinoembryonic antigen or CA19-9 levels in serum or in pure pancreatic juice, imaging, and cytological methods. Within 40.8 months mean follow-up after surgery (range 2-96 months), three patients (16%), two with malignant and one with benign tumor, had tumor relapse after respectively 7, 27, and 14 months. Margins were positive without malignant features in the two malignant cases and negative in the other case. Tumor relapse was malignant with diffuse spreading in the three cases, and the patients died within 34 months after surgical resection. CONCLUSIONS: Our series and the review of the literature indicate that preoperative indicators of malignancy in IPMT are still lacking. Concerning resection margins, complete tumor resection is usually possible by segmental pancreatectomy. Malignant relapses are not exceptional. Incomplete resection and diffuse or multifocal tumor represent poor prognostic factors. Total pancreatectomy should be considered in such cases.     

Intraductal papillary mucinous tumors of the pancreas

Cystic neoplasms of the exocrine pancreas are a small fraction of pancreatic tumors. Within that group of cystic neoplasms, intraductal papillary mucinous tumors (IPMTs) can be distinguished from mucinous cystic neoplasms, serous cystic neoplasms, and pseudopapillary cystic tumors. Awareness of IPMTs has increased since the World Health Organization classified these tumors as its own group in 1996. Because of their favorable prognosis, an extensive diagnostic workup for IPMTs should be performed in patients presenting with cystic lesions of the pancreas. This workup often leads to the diagnosis and the predominant tumor location and size, although the extent of the ductal changes can only be established by histopathology. Surgical resection is the therapy of choice for IPMTs. The type of resection depends upon the extent of the quantitative and qualitative ductal involvement. Total pancreatectomy is currently the treatment for an IPMT that comprises the entire main duct.     

Extrapancreatic neoplasms occur with unusual frequency in patients with intraductal papillary mucinous tumors of the pancreas

OBJECTIVE: Intraductal papillary mucinous tumor (IPMT) of the pancreas has a favorable prognosis. Non-pancreatic primary neoplasms have potential prognostic significance in patients with IPMT. This study focused on the incidence and characteristics of nonpancreatic neoplasms in IPMT patients. METHODS: Forty-two patients (mean age, 64 yr) with IPMT underwent surgery; 16 had adenoma and 26 adenocarcinoma. Preoperative and postoperative, nonpancreatic neoplasms were investigated. The mean postoperative follow-up period was 4.2 yr (range, 0.2-13 yr). Furthermore, 46 patients with pancreatic ductal adenocarcinoma were analyzed for nonpancreatic neoplasms. RESULTS: Five-year survival rates were 100% for benign and 82% for malignant IPMT. Twenty patients (48%) had nonpancreatic neoplasms, before (n = 11), at (n = 4), and after (n = 10) surgery for IPMT. Fifteen patients (32%) had nonpancreatic malignancies. Nonpancreatic neoplasms included colorectal adenomas (21%) and adenocarcinomas (12%), and gastric carcinomas (10%). One patient died of subsequent bile duct carcinoma. Development of nonpancreatic neoplasms was related to age but not to gender, family history, adjuvant chemotherapy, or IPMT pathology. The incidences of nonpancreatic neoplasms and malignancies were significantly higher in patients with IPMT than in those with pancreatic ductal adenocarcinoma (11% and 7%, respectively). CONCLUSIONS: IPMT is associated with a high incidence of nonpancreatic neoplasms, particularly colorectal neoplasms. In IPMT patients, systemic surveillance may allow early detection of second tumors. In preoperative screening and postoperative follow-up of patients with nonpancreatic neoplasms, the possibility of IPMT should be considered.     

Clinicopathological and immunohistochemical analysis of malignant features in mucinous cystic tumors of the pancreas

BACKGROUND/AIMS: To investigate the malignancy of mucinous cystic tumors (MCTs) of the pancreas, we examined clinicopathological features and immunohistochemical findings of MCT. METHODOLOGY: We analyzed the expression of p53 protein, proliferating cell nuclear antigen, alpha6-integrin subunit, alpha5beta1-integrin, and interleukin-1 receptor type I in tumor specimens from eight patients with MCT. RESULTS: The tumors were classified as mucinous cyst adenoma (n=6) or mucinous cyst adenocarcinoma (n=2). The actuarial five-year survival rate was 83.3%. All in eight MCTs had 'ovarian-type' stroma in the cyst wall. The alpha6-integrin subunit and p53 protein were expressed in adenocarcinoma tissues of MCTs, and in two adenomas the alpha6-integrin subunit and p53 protein were also co-expressed. CONCLUSIONS: Our present results indicate that coexpression of the alpha6-integrin subunit and p53 protein should be appreciated as an indicator of malignancy in MCTs.     

IHPBA in Tokyo, 2002: surgical treatment of IPMT vs MCT: a Japanese experience

The differences and similarities between intraductal papillary mucinous tumor (IPMT) and mucinous cystadenoma or carcinoma (mucinous cystic tumor; MCT) of the pancreas have been noted. The similarities include: (1) both tumors originate from pancreatic duct cells, (2) massive mucin production is found in both tumors, and (3) papillary projection is a common histological characteristic. However, there are also many differences. IPMT is most frequently found in men in their sixties, and originates in the head of the pancreas, with 62% (123/199) of tumors reported to be found in the head of the pancreas. This tumor sometimes spreads throughout the entire pancreas. The tumor itself basically is of the dilated pancreatic duct type, and the prognosis is generally good. In contrast, MCT frequently develops in women in their forties. This tumor is usually large, round, and almost totally encapsulated by fibrous tissue, with no communication with the pancreatic duct. The tumor histologically has an ovarian-like stroma. It most often develops in the body or tail of the pancreas. Invasion is often present and the operative prognosis is not good. IPMT resembles the shape of a bunch of grapes and MCT resembles that of an orange. From the differences between these two types of tumors, they are classified into different categories. With regard to therapeutic strategies for MCT, the tumor should be resected with lymph node dissection immediately when it is detected. In contrast, some patients with branch-type IPMT can be followed without surgical procedures. Because IPMT shows good prognosis and little tendency for infiltration, some kinds of organ-preserving procedures would be possible for some patients with this tumor. Such organ-preserving procedures are: duodenum-preserving pancreas head resection, spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein, and so on.     

Clinicopathologic features and outcomes of intraductal papillary-mucinous tumors of the pancreas

BACKGROUND/AIMS: The authors reviewed their experience with resected IPMT (intraductal papillary-mucinous tumor) of the pancreas to clarify the characteristics and prognosis of this neoplasm. METHODOLOGY: Between 1983 and 1998, 30 consecutive patients with IPMT underwent operations at our institution. Their clinicopathological features and postoperative long-term outcomes were analyzed retrospectively. RESULTS: There were 22 males and 8 females, with a mean age of 64 years. Operations performed were duodenum-preserving pancreatic head resection in 12 patients, distal pancreatectomy in 8, segmental pancreatectomy in 6, conventional pancreaticoduodenectomy in 4. Malignancy was found in 10 of 30 (33%). Factors significantly associated with malignancy were tumor size or presence in main pancreatic duct. In 30 resected patients after a mean follow-up of 60 months, tumor recurrence had occurred in 2 cases of invasive carcinoma that infiltrated into the extrapancreatic organ. The overall actuarial 5-year and 10-year survival was 83% and 62%, respectively. CONCLUSIONS: IPMT has a favorable prognosis after adequate resection. Despite slow growth, IPMT has an obvious malignant potential and a poor prognosis when invasive carcinoma has developed. Early recognition and pancreatectomy is the mainstay of treatment for IPMT.     

Minute invasive ductal carcinoma of the residual pancreas after distal pancreatectomy for intraductal papillary-mucinous tumor

Summary Our report describes a 66-yr-old man who underwent surgical resection of the pancreas twice within a period of 3 yr for primary and recurrent intraductal papillary mucinous tumors (IPMTs). During the second operation, a minute invasive ductal carcinoma (IDC) was accidentally discovered in the resected specimen of the residual pancreas. The similarity and continuity between this IDC and recurrent IPMT were not recognized histologically. A solid tumor was found in the hepatoduodenal ligament 3 mo after the second operation. We performed a third operation, performing laparotomy and intra-operative radiotherapy, but could not extirpate the tumor. A biopsy specimen obtained from the tumor during this third operation revealed adenocarcinoma, and the patient later died because of tumor progression. We immunohistochemically analyzed the expression of HER-2/neu, Smad4, p16, p21, p53, mucin immunophenotypes and the Ki-67 labeling index in this series of pancreatic-duct neoplasias. Overexpression of HER-2/neu and loss of Smad4 were detected in the minute IDC, which was very different from the immunohistochemical features of both the primary and recurrent IPMTs. The IDC also showed a MUC1-positive/MUC2-negative phenotype. Therefore, we suggest that de novo IDC may occur in IPMT patients, especially those with multiple tumor recurrence. The present case may be helpful in understanding the pathogenesis of pancreatic duct lesions.     

Intraductal papillary-mucinous tumors of the pancreas: Clinicopathologic features, outcome, and nomenclature. Members of the Pancreas Clinic, and Pancreatic Surgeons of Mayo Clinic

BACKGROUND & AIMS: Intraductal papillary-mucinous tumor (IPMT) of the pancreatic ducts is increasingly recognized. This study investigated if clinical, imaging, or, histological features predicated outcome, formulated a treatment algorithm, and clarified relationships among IPMT, mucinous cystic neoplasms of the pancreas (MCN), and chronic pancreatitis. METHODS: The medical records, radiographs, and pathological specimens of 15 patients with IPMT (dilated main pancreatic duct or branch ducts with mucin overproduction) who were evaluated between October 1983 and January 1994 were reviewed. RESULTS: One patient had hepatic metastases. Fourteen underwent an operation (6 distal pancreatectomy, 4 total pancreatectomy, and 4 pancreaticoduodenectomy); all had dysplastic intraductal epithelium and chronic pancreatitis, whereas 3 had invasive adenocarcinoma. After a median of 25 months, 10 patients were alive; 3 of 4 with malignant and 2 of 11 with benign IPMT died (P < 0.05). Patients with or without carcinoma had similar clinical and radiographic features. A clinical diagnosis of chronic pancreatitis had been made in 9 patients with benign IMPT and in none with malignant IPMT (P < 0.05). CONCLUSIONS: IPMT is a dysplastic and likely precancerous lesion that is frequently diagnosed as chronic pancreatitis and is separate from MCN. Because it is not possible to distinguish noninvasive from invasive IPMT preoperatively, complete surgical excision of the dysplastic process is our treatment of choice whenever appropriate. (Gastroenterology 1996 Jun;110(6):1909-18)     

Intraductal papillary-mucinous tumors of the pancreas: differential diagnosis between benign and malignant tumors by endoscopic ultrasonography

OBJECTIVES: Recently, intraductal papillary-mucinous tumor (IPMT) of the pancreas has increasingly been recognized. However, differential diagnosis between benign and malignant IPMT is often difficult using conventional imaging modalities. The purpose of this study was to retrospectively investigate the value of endoscopic ultrasonography (EUS) for differentiating malignant from benign IPMT. METHODS: A total of 51 patients with IPMT were preoperatively examined by EUS. The endosonograhic findings were compared with histopathological findings of the resected specimens. RESULTS: In main duct type IPMT, the diameter of the main pancreatic duct (MPD) was > or =10 mm in seven of the eight malignant tumors, compared with two of the seven benign tumors (p < 0.05). In branch duct type IPMT, three of the four large tumors (>40 mm) with irregular thick septa were malignant lesions. In both main duct type IPMT and branch duct IPMT, eight patients had large mural nodules (>10 mm); seven of the eight tumors were malignant and one of the eight tumors was benign. When the tumor was diagnosed as malignant according to above three findings, EUS was able to differentiate between malignant and benign IPMT with an accuracy of 86%. CONCLUSIONS: Main duct type tumors with > or =10 mm dilated MPD, branch duct type tumors (>40 mm) with irregular septa, and large mural nodules (>10 mm) strongly suggest malignancy on EUS. EUS would be a useful modality for differentiating between benign and malignant IPMT.     

Intraductal papillary-mucinous tumor of the pancreas concomitant with ductal carcinoma of the pancreas

Background: Despite the recent progress of diagnostic and therapeutic modalities, the clinical course of patients with ductal carcinoma (DC) of the pancreas remains dismal. Intraductal papillary-mucinous tumor of the pancreas (IPMT) is sometimes accompanied by malignant diseases of the other organs and pancreatic adenocarcinoma. Thus, IPMT may be a potential diagnostic clue to DC of the pancreas at early phase. Methods: Clinico-pathologic findings of 7 Japanese patients with IPMT of the pancreas concomitant with independent DC were examined and compared with those of 69 patients with IPMT alone and of 70 with DC alone. Results: The seven patients corresponded to 9.2% of 76 patients with IPMT and 9.1 % of 77 patients with DC. The seven male patients ranged from 55 to 75 years with a mean of 64.3. DC was synchronous with IPMT in five patients, metachronous to IPMT (4 years after IPMT) in one, and synchronous with IPMT and metachronous to IPMT and DC (7 years after IPMT) in the other. In 4 patients, the presence of IPMT led to the diagnosis of DC. All the 7 IPMTs were of branch type with a mean diameter of 3.0 cm. The IPMT was located in the head of the pancreas in 3, body in 2 and tail in the other 2. All the 7 IPMTs were adenoma with mild dysplasia. Two of the 7 patients with DC had in situ carcinoma, 1 minimally invasive carcinoma and the remaining 4 invasive carcinoma. The mean diameter of seven DCs (3.0 cm) with IPMT were smaller than that of 70 DCs (3.6 cm) (8P = 0.0295). Stage (stage I/II/III/IV = 3/0/3/1) of the seven DCs concomitant with IPMT were significantly earlier than that (stage I/II/III/IV = 5/6/28/31) of the other 70 (p = 0.0203). The survival curve of the 7 patients with IPMT and DC was significantly better than that of the 70 with DC alone (p = 0.0460). Conclusions: Clinicians should pay attention to the possible presence of DC of the pancreas in male patients with intraductal papillary-mucinous adenoma of the pancreas of branch type in their 6th to 8th decades.     

IDUS IN THE DIAGNOSIS OF IPMT

Intraductal papillary mucinous tumor of the pancreas (IPMT) is considered as having low‐grade malignant potential, and malignancy is not infrequent. Therefore, accurate diagnosis is indispensable for appropriate patient care. IPMT is classified mainly into two categories based on the distribution of tumor, the main duct type and the branch duct type. In the diagnosis of IPMT, there are four important points: differentiation of IPMT from other pancreatic pathologies; differentiation of malignancy from benign lesions; evaluation of tumor extent along the MPD; and investigation of duct cell carcinoma coexistent with or derived from IPMT. IPMT should be distinguished from chronic pancreatitis, ductal adenocarcinoma, or cystic neoplasms. IPMT often requires pancreaticoduodenectomy for cure, but such invasive surgery should be avoided in patients with benign hyperplasia. Mural nodules in the MPD can be clearly visualized by intraductal ultrasonography (IDUS). Measurement of the height of the tumor mass by IDUS is useful in distinguishing benign from malignant IPMT. Intraductal spread of IPMT along the MPD is demonstrated by IDUS as irregular thickening of the MPD wall. To achieve a tumor‐free margin in surgery, evaluation by IDUS of the extent of the tumor along the MPD is important. The expected accuracy of IDUS in the diagnosis of invasive IPMT is reportedly over 90%.     

胰管内乳头状黏液瘤的临床研究

目的 通过探讨胰管内乳头状黏液瘤（IPMT）的临床、逆行胰胆管造影（ERCP）表现及病理特征,提高对IPMT的认识。方法 对9例IPMT患者的临床、影像学表现及病理资料作回顾性分析。结果 9例中男女之比为2：1,年龄为37-76岁,平均68.4岁。上腹痛为最常见症状。肿瘤主要位于胰头部。ERCP可见十二指肠乳头肿大开口扩大,见大量黏液流出及主胰管扩张。病理表现多样性,可表现为腺瘤和腺癌。结论 IMPT是胰腺肿瘤的一种,其预后较一般的胰腺癌好,临床上应将其与其他胰腺肿瘤加以区别。     

Surgical treatment of intraductal papillary-mucinous tumor (IPMT) of the pancreas: operative indications based on surgico-pathologic study focusing on invasive carcinoma derived from IPMT

Background/Purpose. Between 1979 and 2000, 51 patients with intraductal papillary-mucinous tumor (IPMT) of the pancreas underwent surgical resection. Methods. The patients were reviewed to disclose the surgical pathology of invasive carcinoma derived from IPMT and to determine the surgical indications for IPMT on the basis of the pathologic findings. Results. The incidence of invasive carcinoma derived from IPMT according to the localization of the tumor was as follows: 4/9 (44%) in the main pancreatic duct (MPD type), 4/9 (44%) showing ductal spread from the MPD to branch ducts (mixed type), and 2/33 (6%) in the 2 branch duct (branch type). The maximal size of the intraductal spread of invasive carcinomas (8 of 18 cases in the MPD and mixed type together and 2 of 33 cases in the branch type) was as follows: 6/8 (75%) in the MPD and mixed type were over 6?cm in size, and the 2-branch-type invasive carcinomas were within the 3-cm size range. Conclusions. We concluded that for both invasive and noninvasive IPMTs, surgical resection was necessary for any MPD or mixed-type IPMTs, and that surgical resection was appropriate for branch-type lesions larger than or equal to 3?cm in diameter, or for lesions smaller than 3?cm showing rapid growth on clinical images.     

Cystic neoplasm of the pancreas: a Japanese multiinstitutional study of intraductal papillary mucinous tumor and mucinous cystic tumor

The Japan Pancreas Society performed a multiinstitutional, retrospective study of 1379 cases of intraductal papillary mucinous tumor (IPMT) and 179 cases of mucinous cystic tumor (MCT) of the pancreas. Clinicopathologic features and postoperative long-term outcomes were investigated. IPMT were most frequently found in men and in the head of the pancreas. In contrast, all patients with MCT were women. Ovarian-type stroma were found in only 42.2% of the MCT cases. Prognostic indicators of malignant IPMT included advanced age, positive symptoms, abundant mucous secretion, presence of large nodules and/or large cysts, remarkable dilatation of the main pancreatic duct, and main duct- or combined-type IPMT. Advanced age, positive symptoms, and presence of large nodules and/or large cysts were predictive of malignant MCT. The 5-year survival rate of IPMT patients was 98%-100% in adenoma to noninvasive carcinoma cases, 89% in minimally invasive carcinoma cases, and 57.7% in invasive carcinoma cases. The 5-year survival rate of MCT patients was 100% in adenoma to minimally invasive carcinoma cases and 37.5% in invasive carcinoma cases. In conclusion, IPMT and MCT show distinct clinicopathologic and prognostic differences. The results from this study may contribute to the diagnosis and treatment of IPMT and MCT.     

Surgical treatment of intraductal papillary-mucinous tumors of the pancreas

BACKGROUND/AIMS: IPMT (Intraductal papillary-mucinous tumor of the pancreas) is increasingly recognized. The aim of this study was to investigate the appropriate surgical treatment for these tumors. METHODOLOGY: Between January 1981 and September 1998, 62 patients with IPMT underwent surgery. We retrospectively examined the clinicopathological features and surgical outcomes of the patients. RESULTS: The types of IPMT were as follows: hyperplasia (20); adenoma (31); and carcinoma, both invasive (5) and noninvasive (6). Lymph node metastasis was found in 36% of the carcinomas. The size of mural nodules was more than 3 mm in all adenoma or carcinoma cases, while the percentage of hyperplasia less than 3 mm was 75%. Intraoperative pancreatoscopy and annular array ultrasonography were very useful, because they detected 10 lesions that could not be found by preoperative examinations, such as computed tomography, endoscopic retrograde pancreatography, and endoscopic ultrasonography. All patients underwent surgical resection, including 10 pancreaticoduodenectomies (Whipple's procedure), 10 pylorus-preserving pancreaticoduodenectomies, 13 pancreatic head resections with segmental duodenectomies, 17 distal pancreatectomies, 9 segmental resections of the pancreas, 2 duodenum-preserving pancreatic head resections, and 1 total pancreatectomy. No operative or hospital death was observed. The postoperative survival rate at 5 years was 71.6% for carcinoma in IPMT. All of the cases with hyperplasia, adenoma and noninvasive carcinoma survived. Only two of the patients with invasive carcinoma died. CONCLUSIONS: IPMT had a favorable prognosis, as compared with pancreatic duct carcinoma. When selecting a surgical procedure for treating these tumors, it is important to confirm the tumor extent, as well as the diagnosis of invasion or noninvasion. In cases with invasion, radical resection is required. On the other hand, organ-function-preserving procedures should be selected for diseases without invasion.     

Natural history of intraductal papillary mucinous tumors of the pancreas: actuarial risk of malignancy.

BACKGROUND & AIMS: Natural history of intraductal papillary mucinous tumors of the pancreas (IPMTs) is unknown. Cross-sectional studies suggest that exclusive branch duct (BD) involvement is associated with a lower risk of carcinoma than main pancreatic duct (MPD) involvement. The aim of our study was to calculate longitudinal risk of malignant transformation of IPMT since the first sign. METHODS: All the patients with a diagnosis of highly probable or histologically proven IPMT were included. Actuarial risks of occurrence of at least low-grade dysplasia (>or=LGD), high-grade dysplasia (>or=HGD), or invasive carcinoma (IC) were calculated by Kaplan-Meier method from the first sign attributable to IPMT. The risks according to sex, acute pancreatitis, tumor size, and involvement of MPD were compared by log-rank test. RESULTS: One hundred six patients were included with a proven (n = 76) or probable (n = 30) IPMT. The tumor was confined to BD in 53 cases. Median duration since the onset of the first sign to the end of follow-up was 21 months (range, 0-241). Ten-year actuarial risk that IPMT grade was >or=LGD, >or=HGD, or IC was 67%, 49%, and 29%, respectively. The only morphologic risk factor of malignant transformation was involvement of MPD, with a 5-year actuarial risk of >or=HGD of 63% in the MPD group compared with 15% in the BD group (P < .001). CONCLUSIONS: Longitudinal risk of at least HGD or IC is time-dependent. Patients with BD IPMT present a much lower risk, justifying a nonoperative surveillance.     

Long-term follow up results of intraductal papillary mucinous tumors of pancreas

BACKGROUND AND AIM: Intraductal papillary mucinous tumor (IPMT) of the pancreas can be divided into three clinically distinct subtypes: main duct type, branch duct type and mixed type. Although it has been reported that the branch duct type IPMT is less invasive than the main duct type IPMT, we experienced a number of branch duct type IPMT having a poor prognosis. In the present study we surveyed the survival and recurrence rates according to the subtypes. METHODS: Sixty-seven IPMT cases were studied to investigate clinical behavior according to the duct types. Diagnostic findings and late results of treatment were reviewed in 27 cases of the main duct type IPMT and in 35 cases of the branch duct type IPMT. RESULTS: There was no statistically significant difference in the survival analysis between the main duct type IPMT and the branch duct type IPMT (P = 0.93). Seven patients (25.9%) died among the main duct type IPMT while six patients (17.1%) died among the branch duct type IPMT (P = 0.36). Tumor recurrence was noticed in four patients (18.1%) among 22 operated main duct type IPMT and in two patients (6.9%) among 29 operated branch duct type IPMT (P = 0.35). CONCLUSION: The long-term follow up result of the branch duct type IPMT is similar to that of the main duct type IPMT. Therefore, it is not safe just to monitor the branch duct type IPMT without operation. Surgery, whenever possible, is clearly the gold standard for treatment of IPMT, regardless of duct type.