Person:

Fernandez-Del Castillo, Carlos

Background: Lymph node metastases are prognostically significant in pancreatic ductal adenocarcinoma. Little is known about the significance of direct lymph node invasion. Aim: The aim of this study is to find out whether direct lymph node invasion has the same prognostic significance as regional nodal metastases. Methods: Retrospective review of patients resected between 1/1/1993 and 7/31/2008. “Direct” was defined as tumor extension into adjacent nodes, and “regional” was defined as metastases to peripancreatic nodes. Results: Overall, 517 patients underwent pancreatic resection for adenocarcinoma, of whom 89 had one positive node (direct 26, regional 63), and 79 had two positive nodes (direct 6, regional 68, both 5). Overall, survival of node-negative patients was improved compared to patients with positive nodes (N0 30.8 months vs. N1 16.4 months; p < 0.001). There was no survival difference for patients with direct vs. regional lymph node invasion (p = 0.67). Patients with one positive node had a better overall survival compared to patients with ≥2 positive nodes (22.3 and 15 months, respectively; p < 0.001). The lymph node ratio (+LN/total LN) was prognostically significant after Cox regression (p < 0.001). Conclusions: Isolated direct invasion occurs in 20% of patients with one to two positive nodes. Node involvement by metastasis or by direct invasion are equally significant predictors of reduced survival. Both the number of positive nodes and the lymph node ratio are significant prognostic factors.

Objective: To determine whether intraductal papillary mucinous neoplasms of the pancreas (IPMNs) have a different genetic background compared with ductal adenocarcinoma (PDAC). Summary Background Data: The biologic and clinical behavior of IPMNs and IPMN-associated adenocarcinomas is different from PDAC in having a less aggressive tumor growth and significantly improved survival. Up to date, the molecular mechanisms underlying the clinical behavior of IPMNs are incompletely understood. Methods: 128 cystic pancreatic lesions were prospectively identified during the course of 2 years. From the corresponding surgical specimens, 57 IPMNs were separated and subdivided by histologic criteria into those with low-grade dysplasia, moderate dysplasia, high-grade dysplasia, and invasive cancer. Twenty specimens were suitable for DNA isolation and subsequent performance of array CGH. Results: While none of the IPMNs with low-grade dysplasia displayed detectable chromosomal aberrations, IPMNs with moderate and high-grade dysplasia showed frequent copy number alterations. Commonly lost regions were located on chromosome 5q, 6q, 10q, 11q, 13q, 18q, and 22q. The incidence of loss of chromosome 5q, 6q, and 11q was significantly higher in IPMNs with high-grade dysplasia or invasion compared with PDAC. Ten of 13 IPMNs with moderate dysplasia or malignancy had loss of part or all of chromosome 6q, with a minimal deleted region between linear positions 78.0 and 130.0. Conclusions: This study is the first to use array CGH to characterize IPMNs. Recurrent cytogenetic alterations were identified and were different than those described in PDAC. Array CGH may help distinguish between these 2 entities and give insight into the differences in their biology and prognosis.

Objectives: To determine the prevalence of incidentally found cases of gallbladder cancer, the incidence of residual disease at reexploration, and the changes in the mode of presentation, treatment, and survival of patients with gallbladder cancer during a period of more than 4 decades. Design: Retrospective case series. Setting: University-affiliated tertiary care center. Patients: Between January 1, 1962, and March 1, 2008, 402 patients with gallbladder cancer were identified and their clinicopathologic data were analyzed. Interventions: Surgical treatment, radiotherapy, and chemotherapy. Main Outcome Measures: Incidentally discovered gallbladder cancer, incidence of residual disease, and differences in presentation, treatment, and survival. Results: Surgical exploration was performed in 260 patients (64.7%), of whom 151 (58.1%) underwent resection. The median age of the patients was 72 years, and 72.3% were female. Between January 1, 1994, and March 1, 2008, 6881 laparoscopic cholecystectomies were performed, and there were 17 incidentally discovered cases of gallbladder cancer (0.25%). Residual disease on reexploration was identified in 0 of 2 patients with T1 tumor, 3 of 13 patients with T2 tumor, and 8 of 10 patients with T3 tumor (P = .01). Patients with stage IV disease (34 [13.1%] diagnosed from 1962-1979; 34 [13.1%] diagnosed from 1980-1997; and 22 [8.5%] diagnosed from 1998-2008) had a median survival of 4 months (range, 0-37 months). Concomitant liver resections increased in the third study period (11.1%, 10.1%, and 54.3%; P < .001), with an increase in negative margins (33.3%, 42.0%, and 63.0%; P = .01). Cox regression analysis identified T stage and surgical margin status as significant prognostic factors. Conclusions: Gallbladder cancer is incidentally found during 0.25% of laparoscopic cholecystectomies. As T stage increases, the likelihood of residual disease on reexploration increases. Although many patients with gallbladder cancer present with incurable disease and have very poor survival, the overall prognosis is improving, likely because of more extensive operations.

Background: Possible mass lesions identified on ultrasound (US) of the gallbladder may prompt an aggressive surgical intervention due to the possibility of a malignant neoplasm. Aim: This study aims to utilize a large modern series of patients with gallbladder lesions identified on US to evaluate imaging characteristics consistent with malignancy. Methods: A retrospective review was conducted of gallbladder ultrasound reports and clinicopathologic data of patients with a mass identified on US. Results: Approximately 59,271 abdominal ultrasounds and 9,117 cholecystectomies were performed between February 2000 and February 2010. We identified 213 patients with a questionable gallbladder neoplasm on ultrasonography who underwent surgical exploration. Median age was 52 years (range = 11–87 years) and 147 (69%) were females. Final pathology demonstrated no neoplasm in 130 patients (61%), while 32 patients (15%) had a wall adenomyoma, 36 (17%) had a polyp (five of which were malignant), 14 (7%) had an adenocarcinoma not arising from a polyp, and one patient had a cystic papillary neoplasm. The smaller the lesion, the more likely it was to be a pseudo-mass. For lesions measuring <5 mm on US, 83% had no lesion found on final pathology. Significant predictors of malignancy were age >52 years (p < 0.001), presence of gallstones on US (p = 0.004), size >9 mm (p < 0.001), evidence of invasion at the liver interface (p < 0.001), and wall thickening >5 mm (p < 0.001). Shape (sessile or penduculated), echogenicity (echogenic or isoechoic), or presence of flow on Doppler were not predictors of malignancy. An US size of ≤9 mm had a negative predictive value of 100% for malignancy. Conclusions: Despite improvements in imaging, most apparent lesions measuring <5 mm on US are not identified in the surgical specimen. US size >9 mm, age >52 years, US suggestion of invasion at the liver interface, and wall thickening >5 mm, especially in the presence of gallstones, should raise the suspicion of malignancy.

INTRODUCTION: The prototypic pancreatic ductal adenocarcinoma shows small-caliber glands that are placed within an exuberant desmoplastic stromal reaction. A number of histologic patterns have been described, and the majority of these patterns are genetically and biologically related to conventional ductal adenocarcinomas. In this report we describe our experience with a heretofore undescribed histologic pattern of pancreatic adenocarcinoma that mimics intraductal papillary mucinous carcinoma, both morphologically and radiologically. METHODS: We identified 10 cases of pancreatic adenocarcinoma with large-caliber malignant glands and an intraluminal papillary pattern. The demographic, clinical, radiologic, and outcome data were recorded. In addition to a review of the histologic features we also performed elastin stains, immunohistochemistry for selected oncogenes and tumor suppressor genes including SMAD4. Immunohistochemical staining for MUC proteins was also performed. RESULTS: The median age of the patients was 67 years, and there were 6 women and 4 men. Grossly, the cut surface in 6 of these cases showed an admixture of solid and cystic areas. The papillary cystic architecture was intimately mixed with areas of conventional adenocarcinoma, the latter characterized by invasive small-caliber tubular structures. None of the tumors showed a pure papillary cystic pattern; however, in 8 cases, this was the predominant pattern (>50% of the tumor). The cysts and papillae were lined predominantly by tall columnar hypermucinous epithelium. Elastin fibers were not identified around these dilated malignant cysts and glands. The intratumoral stroma was paucicellular and hyalinized. Seven of the 10 tumors were negative for SMAD4. The lack of pericystic elastin fibers and loss of SMAD4 in the majority of cases argue against these lesions representing an intraductal papillary mucinous neoplasm. All 10 tumors stained for MUC1; focal MUC2 reactivity was noted in 1 case. The majority of cases were positive for MUC5AC (9/10) and MUC6 (8/10). Seven patients died of their disease, whereas 1 patient is alive with widely metastatic disease. Two patients were lost to follow up. CONCLUSIONS: The adenocarcinoma described herein is a unique morphologic pattern of pancreatic ductal adenocarcinoma. The biology and genetics (as estimated by immunohistochemistry) are no different from that of conventional ductal adenocarcinoma but are distinctly different from that

Pancreatic acinar cystadenomas (ACAs) are rare cystic lesions showing acinar differentiation with benign outcome. Although debated, ACAs are favored to be neoplastic and potentially the benign counterpart of acinar cystadenocarcinoma. We present the largest single institution series to date comprising 10 cases. The mean age was 49 years with a female predominance (M:F=1:2.3). Abdominal/flank pain was the most common presentation (n=6). Serum amylase/lipase and cyst fluid amylase were often elevated. All lesions had a benign outcome on follow-up (5 to 67 mo). The lesions were unilocular (n=3) or multilocular (n=7) with mean size of 3.8 cm (range, 2.9 to 5.0 cm) and 5.1 cm (range, 2.0 to 7.5 cm), respectively. Eight lesions were unifocal with locations as follows: head (n=2), head/neck (n=2), body (n=1), tail (n=1), predominantly extrapancreatic with a microscopic intrapancreatic component (n=1), and unspecified location (n=1). Two lesions were multifocal, involving the head/uncinate/body and pancreatic head, respectively. Two aspects of ACAs that may represent a diagnostic pitfall include the propensity for acinar epithelium to appear as nondescript flat/cuboidal epithelium (trypsin/chymotrypsin immunopositive) and epithelial heterogeneity, with focal mucinous and squamous epithelium, the latter particularly in multilocular variants. In addition, 2 cases with intracystic nodules were observed. Array comparative genomic hybridization performed on 1 of these cases showed multiple chromosomal gains involving 1p, 3p, 5q, 6p, 7q, 8, 10q, 11, 14, 20, and X. These findings provide preliminary evidence that ACAs represent a cystic neoplastic lesion.

Background: Pancreatic ductal adenocarcinoma represents 90% of pancreatic cancers and is an important cause of cancer death in the United States. Operative resection remains as the only treatment providing prolonged survival, but even after a curative resection, 5-year survival rates are low. Our aim was to identify the prognostic factors for long-term survival after resection of pancreatic ductal adenocarcinoma related to patients, treatments, and tumor biology. Methods: Retrospective review identified 959 patients who underwent resection of their pancreatic adenocarcinoma between February 1985 and December 2010, of whom 499 were resected before November 2006 and represent the cohort we describe in this study. Patient, tumor, and treatment-related variables were assessed for their associations with 5- and 10-year overall survival. Results: Of the 499 patients, 49% were female and median age was 65 years. The majority of patients had stage IIb disease (60%). Actual 5-year survival after resection of pancreatic adenocarcinoma was 19% (95/499), and actual 10-year survival was 10% (33/329). Significant clinicopathologic factors predicting 5- and 10-year survival were negative margins and negative nodal status. Interestingly, 41% (39/95) of long-term survivors had positive nodes and 24% (23/95) had positive margins. Conclusion: Pancreatic ductal adenocarcinoma demonstrates a very heterogeneous biology, but patients with negative resection margins and node negative cancers are more likely to survive 5 years after resection. However, our series demonstrates that the biology of the cancer rather than simple pathologic factors determine a patient's prognosis.

IgG4-related disease is a newly recognized fibro-inflammatory condition characterized by several features: a tendency to form tumefactive lesions in multiple sites; a characteristic histopathological appearance; and—often but not always—elevated serum IgG4 concentrations. An international symposium on IgG4-related disease was held in Boston, MA, on 4–7 October 2011. The organizing committee comprising 35 IgG4-related disease experts from Japan, Korea, Hong Kong, the United Kingdom, Germany, Italy, Holland, Canada, and the United States, including the clinicians, pathologists, radiologists, and basic scientists. This group represents broad subspecialty expertise in pathology, rheumatology, gastroenterology, allergy, immunology, nephrology, pulmonary medicine, oncology, ophthalmology, and surgery. The histopathology of IgG4-related disease was a specific focus of the international symposium. The primary purpose of this statement is to provide practicing pathologists with a set of guidelines for the diagnosis of IgG4-related disease. The diagnosis of IgG4-related disease rests on the combined presence of the characteristic histopathological appearance and increased numbers of IgG4+ plasma cells. The critical histopathological features are a dense lymphoplasmacytic infiltrate, a storiform pattern of fibrosis, and obliterative phlebitis. We propose a terminology scheme for the diagnosis of IgG4-related disease that is based primarily on the morphological appearance on biopsy. Tissue IgG4 counts and IgG4:IgG ratios are secondary in importance. The guidelines proposed in this statement do not supplant careful clinicopathological correlation and sound clinical judgment. As the spectrum of this disease continues to expand, we advocate the use of strict criteria for accepting newly proposed entities or sites as components of the IgG4-related disease spectrum.

Background and aims: Pancreatic cyst fluid (PCF) CEA has been shown to be the most accurate preoperative test for detection of cystic mucinous neoplasms (CMNs). This study aimed to assess the added value of PCF KRAS mutational analysis to CEA for diagnosis of CMNs. Patients and methods: This is a retrospective study of prospectively collected endoscopic ultrasonography (EUS) fine-needle aspiration (FNA) data. KRAS mutation was determined by direct sequencing or equivalent methods. Cysts were classified histologically (surgical cohort) or by clinical (EUS or FNA) findings (clinical cohort). Performance characteristics of KRAS, CEA and their combination for detection of a cystic mucinous neoplasm (CMN) and malignancy were calculated. Results: The study cohort consisted of 943 patients: 147 in the surgical cohort and 796 in the clinical cohort. Overall, KRAS and CEA each had high specificity (100 % and 93.2 %), but low sensitivity (48.3 % and 56.3 %) for the diagnosis of a CMN. The positivity of KRAS or CEA increased the diagnostic accuracy (80.8 %) and AUC (0.84) significantly compared to KRAS (65.3 % and 0.74) or CEA (65.8 % and 0.74) alone, but only in the clinical cohort (P < 0.0001 for both). KRAS mutation was significantly more frequent in malignant CMNs compared to histologically confirmed non-malignant CMNs (73 % vs. 37 %, P = 0.001). The negative predictive value of KRAS mutation was 77.6 % in differentiating non-malignant cysts. Conclusions: The detection of a KRAS mutation in PCF is a highly specific test for mucinous cysts. It outperforms CEA for sensitivity in mucinous cyst diagnosis, but the data does not support its routine use.

Patient-derived xenograft (PDX) tumors are powerful tools to study cancer biology. However, the ability of PDX tumors to model the biological and histological diversity of pancreatic ductal adenocarcinoma (PDAC) is not well known. In this study, we subcutaneously implanted 133 primary and metastatic PDAC tumors into immunodeficient mice. Fifty-seven tumors were successfully engrafted and even after extensive passaging, the histology of poorly-, moderately-, and well-differentiated tumors was maintained in the PDX models. Moreover, the fibroblast and collagen contents in the stroma of patient tumors were recapitulated in the corresponding PDX models. Analysis of the clinicopathological features of patients revealed xenograft tumor engraftment was associated with lymphovascular invasion (P = 0.001) and worse recurrence-free (median, 7 vs. 16 months, log-rank P = 0.047) and overall survival (median, 13 vs. 21 months, log-rank P = 0.038). Among successful engraftments, median time of growth required for reimplantation into new mice was 151 days. Reflective of the inherent biological diversity between PDX tumors with rapid (<151 days) and slow growth, differences in their growth were maintained during extensive passaging. Rapid growth was additionally associated with lymph node metastasis (P = 0.022). The association of lymphovascular invasion and lymph node metastasis with PDX formation and rapid growth may reflect an underlying biological mechanism that allows these tumors to adapt and grow in a new environment. While the ability of PDX tumors to mimic the cellular and non-cellular features of the parental tumor stroma provides a valuable model to study the interaction of PDAC cells with the tumor microenvironment, the association of successful engraftment with adverse clinicopathological features suggests PDX models over represent more aggressive forms of this disease.