David S Klimstra

Memorial Sloan-Kettering Cancer Center, New York City, New York, United States

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Publications (381)2061.26 Total impact

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    ABSTRACT: Mono-allelic germline mutations in DNA mismatch repair (MMR) genes lead to Lynch syndrome (LS). Questions remain as to the timing of the inactivation of the wild-type allele in LS-associated tumorigenesis. Speculation exists that it happens after the neoplasia has been initiated. However, a recent study reported the presence of MMR-deficiency in non-neoplastic colonic crypts in LS; thus the possibility can be raised that these crypts may be tumor precursors, and as such, biallelic loss of MMR may occur prior to neoplasia. Here we report a unique case that showed findings supporting both of the two seemingly conflicting notions. The patient was a 40-year-old female with LS, MSH2 type, who underwent a segmental colectomy for an adenocarcinoma. By immunohistochemistry, the carcinoma lost MSH2/MSH6. Interestingly, there was also complete loss of MSH2/MSH6 in a distinct focus of 20 colonic crypts that were morphologically non-neoplastic, thus supporting the possibility of biallelic loss of MMR before initiation of neoplasia. However, in a separate adenoma, MMR was preserved in neoplastic glands with low grade dysplasia and lost only in glands with high grade dysplasia, i.e., MMR loss after tumor initiation. These are relevant findings with regard to the timing of MMR deficiency in LS tumorigenesis, and bring forth the possibility that varied tumorigenic pathways may exist. Additionally, we observed that the MMR-deficient non-neoplastic crypts harbored increased intraepithelial CD8-positive T-lymphocytes similar to the patient's carcinoma, providing a potential new venue for the study of the natural antitumor immune responses in LS individuals.
    Familial Cancer 08/2014; · 1.94 Impact Factor
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    ABSTRACT: Acinar cell carcinoma (ACC), including its mixed variants, is a rare pancreatic malignancy. Recent reports have documented its occurrence in Lynch syndrome. Our aim was to evaluate the frequency and clinicopathologic significance of DNA mismatch repair (MMR) deficiency in ACCs in general.
    Pancreas 07/2014; · 2.95 Impact Factor
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    ABSTRACT: The role for neoadjuvant systemic therapy in resectable pancreas adenocarcinoma remains undefined.
    Annals of surgery. 07/2014; 260(1):142-148.
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    ABSTRACT: Histologic classification of ampullary carcinomas into intestinal, pancreatobiliary, or other subtypes is easily achievable in some cases but difficult in others. Immunohistochemical (IHC) stains may allow distinction between the subtypes; however, their added value to routine hematoxylin and eosin (H&E) evaluation has not been systematically evaluated. Inconsistent histologic subtyping has hampered current clinical research and therapeutic trials. In this study, a consecutive series of 105 ampullary carcinomas was subtyped first by H&E evaluation and then by the evaluation of an IHC panel composed of CK7, CK20, CDX2, MUC1, and MUC2, and the added value of IHC was analyzed. By H&E, a consensus diagnosis, defined as concordant subtyping among at least 3 of the 4 independent study pathologists, was achieved in 81 of the 105 (77%) cases. There was excellent agreement for poorly differentiated and mucinous subtypes (κ=0.72 and 0.89, respectively) but only good agreement for intestinal and pancreatobiliary subtypes (κ=0.57 and 0.48, respectively) and poor agreement for mixed subtype (κ=0.09). By IHC, CK7 showed no informative value (being positive in ≥70% of the cases in both intestinal and pancreatobiliary subtypes), whereas a subtyping schema incorporating the combination staining patterns of CK20, CDX2, MUC1, and MUC2 did. By this schema, "intestinal subtype" was defined as having (1) positive staining for CK20 or CDX2 or MUC2 and negative staining for MUC1, or (2) positive staining for CK20, CDX2, and MUC2, irrespective of the MUC1 result; and "pancreatobiliary subtype" was defined as having positive staining for MUC1 and negative staining for CDX2 and MUC2, irrespective of CK20 results. Cases not fitting one of these 3 categories were regarded as "ambiguous" immunohistochemically. By combining this schema with H&E evaluation, 97 of the 105 cases (92%) could be classified into either intestinal or pancreatobiliary subtype. In particular, immunophenotyping allowed categorization of 75% of poorly differentiated adenocarcinomas and 69% of cases with mixed histologic features as either intestinal or pancreatobiliary subtype. Most mucinous adenocarcinomas (88%) were clearly intestinal subtype by IHC. Thus, our IHC schema enhanced the subtyping of ampullary carcinoma and, in combination with H&E evaluation, allowed a dichotomous classification in 92% of the cases. Should further independent studies reaffirm our findings, this schema may serve as a valuable tool in both diagnostic and research settings.
    The American journal of surgical pathology 05/2014; · 4.06 Impact Factor
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    ABSTRACT: The minor duodenal papilla drains the accessory pancreatic duct of Santorini and lies proximal to the ampulla of Vater. Adenocarcinoma and its precursor lesions arising in the minor papilla are rare. Literature data thus far are limited to a few individual case reports, and the condition is consequently poorly defined. Our study cases were composed of carcinomas fulfilling all of the following criteria: location at 1.5 to 2.5 cm proximal to the major papilla; presence of associated submucosal pancreatobiliary-type ducts with periductal glands or acinar tissue; a predominant submucosal location of the tumor; and lack of an intestinal-type adenoma in the adjacent duodenal mucosa. Tumors were studied morphologically, immunohistochemically, and clinically. Nine cases fulfilling the inclusion criteria were identified. There were 5 men and 4 women with an age range of 50 to 76 years (median, 72 y). The tumor size ranged from 1.2 to 4.4 cm (median, 3 cm). The carcinomas were of colloid type (3 tumors), pancreatobiliary type (4), or nonmucinous intestinal type (2). Five cases were associated with an intraductal papillary mucinous neoplasm (IPMN)-like precursor lesion within the residual structures of the minor papilla in the duodenal submucosa. Immunohistochemically, the intestinal-type and mucinous-type tumors tended to be positive for CK20, CDX2, MUC2, and B72.3, and pancreatobiliary-type tumors tended to be positive for CK7, MUC1, B72.3, and CA125. Loss of DPC4 (Smad4) expression was found in the pancreatobiliary-type carcinomas only. Two tumors showed loss of DNA mismatch-repair protein expression, one losing MLH1 and PMS2 and the other losing MSH6. Both patients were older than 60 years, and neither had germline mutation testing. Follow-up information was available for 6 patients (median follow-up time, 67.5 mo): 3 of the 6 patients died of disease at 60, 75, and 85 months after surgery, respectively, and all 3 patients had an intestinal-type carcinoma (1 colloid and 2 nonmucinous). The patient whose tumor was MSH6 deficient was alive without evidence of disease 51 months after surgery. In conclusion, adenocarcinomas of the minor papilla are rare tumors occurring predominantly in the sixth to seventh decade. Some of them arise from IPMN-like precursors in the residual submucosal minor papilla tissue. Morphologically, immunohistochemically, and clinically they are similar to ampullary or IPMN-associated pancreatic carcinomas and can exhibit either an intestinal, colloid, or pancreaticobiliary phenotype. DNA mismatch-repair deficiency may occur. A careful gross and histologic examination is essential to accurately recognize the site of origin of minor papilla carcinomas.
    The American journal of surgical pathology 04/2014; 38(4):526-33. · 4.06 Impact Factor
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    ABSTRACT: Gastroenteropancreatic (GEP) neuroendocrine neoplasms are classified as low-grade, intermediate-grade, and high-grade tumors based on morphologic criteria and the proliferation rate. Most studies have been conducted in patients with well differentiated (low-grade to intermediate-grade) neuroendocrine tumors. Data are substantially scarcer on poorly differentiated, high-grade neuroendocrine carcinoma (NEC), which includes the entities of small cell carcinoma and large cell NEC. A literature search of GEP-NEC was performed. Long-term survival was poor even among patients who presented with localized disease. Several studies highlighted heterogeneity within the high-grade NEC category and a need for the further identification of discreet prognostic and predictive groups. Tumors with a Ki-67 proliferation index <55% were less responsive to platinum-based chemotherapy, and patients with such tumors or with well differentiated morphology had better survival than patients who had tumors with poorly differentiated morphology or a higher Ki-67 index. Treatment options beyond platinum-based chemotherapy are emerging. A revision of the World Health Organization high-grade NEC classification seems to be necessary based on recent data. Platinum-based chemotherapy may not be the optimal treatment for patients who have GEP-NEC with a moderately high proliferation rate. Adequate diagnostic and prognostic stratifications constitute the basis for future progress. Cancer 2014. © 2014 American Cancer Society.
    Cancer 04/2014; · 5.20 Impact Factor
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    ABSTRACT: For patients with unresectable intrahepatic cholangiocarcinoma (ICC), treatment options are limited and survival is poor. This study summarizes the long-term outcome of two previously reported clinical trials using hepatic arterial infusion (HAI) with floxuridine and dexamethasone (with or without bevacizumab) in advanced ICC. Prospectively collected clinicopathologic and survival data were retrospectively reviewed. Response was based on Response Evaluation Criteria in Solid Tumors (RECIST). Pre-HAI dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) images were reviewed, and tumor perfusion data correlated with outcome. Forty-four patients were analyzed (floxuridine, 26; floxuridine/bevacizumab, 18). At a median follow-up of 29.3 months, 41 patients had died of disease. Partial response by RECIST was observed in 48 %, and 50 % had stable disease. Three patients underwent resection after response, and 82 % received additional HAI after removal from the trials. Median survival was similar in both trials (floxuridine 29.3 months vs. floxuridine/bevacizumab 28.5 months; p = 0.96). Ten (23 %) patients survived ≥3 years, including 5 (11 %) who survived ≥5 years. Tumor perfusion measured on pre-treatment DCE-MRI [area under the gadolinium concentration curve at 90 and 180 s (AUC90 and AUC180, respectively)] was significantly higher in ≥3-year survivors and was the only factor that distinguished this group from <3-year survivors (mean AUC90 22.6 vs. 15.9 mM s, p = 0.025, and mean AUC180 48.9 vs. 32.3 mM s, p = 0.003, respectively). Median hepatic progression-free survival was longer in ≥3-year survivors (12.9 vs. 9.3 months, respectively; p = 0.008). HAI chemotherapy can result in prolonged survival in unresectable ICC. Pre-HAI DCE-MRI may predict treatment outcome.
    Annals of Surgical Oncology 03/2014; · 4.12 Impact Factor
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    ABSTRACT: Receptor tyrosine kinases (RTK) are in the focus of targeted therapy for epithelial tumors. This study addressed the role of EGFR, HER2 and HER3 expression and dimerization in esophageal cancers in situ and in vitro in context of therapeutic EGFR and HER2 inhibitors. In archival pre-treatment biopsies of esophageal carcinomas (n=110), EGFR was preferentially expressed in esophageal squamous cell carcinomas (ESCCs) (22.4%; p=0.088) and HER2 (34.4%; p<0.001) with HER3 (91.5%; p<0.001) in esophageal (Barrett's) adenocarcinomas (EACs). In situ proximity ligation assays revealed mainly EGFR and HER2 homodimers in ESCC and EAC cases, respectively. However, EAC cases also exhibited HER2/HER3 heterodimers. In vitro ESCC (OE21) cells displayed a significant response to Erlotinib, Gefitinib as well as Lapatinib, with loss of AKT phosphorylation, G0/G1 cell cycle arrest and induction of apoptosis. In EAC cells (OE19, OE33, SK-GT-4), Lapatinib was similarly effective in strongly HER2-positive (mainly HER2 homodimers, some HER2/EGFR heterodimers) OE19 and OE33 cells. The HER2-targeting antibodies (Trastuzumab, Pertuzumab) given alone were largely ineffective in ESCC and EAC cells. However, both antibodies significantly induced antibody-dependent cellular cytotoxicity in EAC (OE19, OE33) cells upon co-culture with peripheral blood mononuclear cells. The study reveals that overexpression of EGFR and HER2 predominantly results in homodimers in ESCCs and EACs, respectively. Still, some EACs also show HER2 dimerization plasticity, e.g. with HER3. Such RTK dimerization patterns affect responses to EGFR and HER2 targeting inhibitors in ESCC and EAC cells in vitro and hence may influence future prediction for particularly HER2-targeting inhibitors in EACs. © 2014 Wiley Periodicals, Inc.
    International Journal of Cancer 02/2014; · 6.20 Impact Factor
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    ABSTRACT: In the pancreas, poorly differentiated neuroendocrine carcinomas include small cell carcinoma and large cell neuroendocrine carcinoma and are rare; data regarding their pathologic and clinical features are very limited. A total of 107 pancreatic resections originally diagnosed as poorly differentiated neuroendocrine carcinomas were reassessed using the classification and grading (mitotic rate/Ki67 index) criteria put forth by the World Health Organization in 2010 for the gastroenteropancreatic system. Immunohistochemical labeling for neuroendocrine and acinar differentiation markers was performed. Sixty-three cases were reclassified, mostly as well-differentiated neuroendocrine tumor (NET) or acinar cell carcinoma, and eliminated. The clinicopathologic features and survival of the remaining 44 poorly differentiated neuroendocrine carcinomas were further assessed. The mean patient age was 59 years (range, 21 to 82 y), and the male/female ratio was 1.4. Twenty-seven tumors were located in the head of the pancreas, 3 in the body, and 11 in the tail. The median tumor size was 4 cm (range, 2 to 18 cm). Twenty-seven tumors were large cell neuroendocrine carcinomas, and 17 were small cell carcinomas (mean mitotic rate, 37/10 and 51/10 HPF; mean Ki67 index, 66% and 75%, respectively). Eight tumors had combined components, mostly adenocarcinomas. In addition, 2 tumors had components of well-differentiated NET. Eighty-eight percent of the patients had nodal or distant metastatic disease at presentation, and an additional 7% developed metastases subsequently. Follow-up information was available for 43 patients; 33 died of disease, with a median survival of 11 months (range, 0 to 104 mo); 8 were alive with disease, with a median follow-up of 19.5 months (range, 0 to 71 mo). The 2- and 5-year survival rates were 22.5% and 16.1%, respectively. Poorly differentiated neuroendocrine carcinoma of the pancreas is a highly aggressive neoplasm, with frequent metastases and poor survival. Most patients die within less than a year. Most (61%) are large cell neuroendocrine carcinomas. Well-differentiated NET and acinar cell carcinoma are often misdiagnosed as poorly differentiated neuroendocrine carcinoma, emphasizing that diagnostic criteria need to be clearly followed to ensure accurate diagnosis.
    The American journal of surgical pathology 02/2014; · 4.06 Impact Factor
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    ABSTRACT: Duodenal neuroendocrine tumors are rare and few studies exist to guide surgical management. This study identifies factors associated with recurrence after resection. A retrospective, single institution review was performed between 1983 and 2011 on patients with a pathologic diagnosis of duodenal neuroendocrine tumor. Tumor grade was assigned based on WHO 2010 criteria (Ki-67 and mitotic rate). Seventy-five patients were identified that underwent curative resection. This included 12 patients with endoscopic mucosal resection, 34 that had local resection, and 29 that underwent pancreaticoduodenectomy. Two-year and 5-year recurrence-free survival was 84 and 81 %, respectively. There were 11 tumor recurrences (either local or distant), and four patients died of their disease (3/4 had high-grade lesions) with an overall median follow-up of 27 months. On univariate analysis, tumor size and tumor grade were identified as being associated with recurrence, but not intervention type, lymph node metastases, ampullary location, or margin status. Tumor grade and size are associated with recurrence-free survival in duodenal neuroendocrine tumors. When feasible, a less aggressive surgical approach to treat low-grade and low-stage duodenal NETs should be considered.
    Journal of Gastrointestinal Surgery 01/2014; · 2.36 Impact Factor
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    ABSTRACT: Choledochal cysts (CDCs) are believed to represent a risk factor for the development of neoplasia. However, the frequency and morphology of neoplastic changes have not been systematically studied, especially in North America. Our aims were to study the frequency and morphology of preneoplastic/neoplastic changes of CDCs. 36 cysts were subjected to clinicopathological analyses. Metaplasia was found in 14/35, of which 9 had Biliary Intraepithelial Neoplasia (BilIN). Of the 14 with metaplasia, 13 showed pyloric gland (PG), 5 intestinal (IN), and 2 squamous. BilINs included 6 BilIN-1, 2 BilIN-2, and 2 BilIN-3. Carcinoma was identified in 5 cases of which 3 were associated with metaplasia and BilIN. Only 1/18 cases without metaplasia had BilIN and none had carcinoma (p=0.0008). There was a trend towards more BilIN and carcinoma with intestinal rather than with pyloric gland metaplasia. All cases with metaplasia or/and BilIN were negative for MUC1. All cases with intestinal metaplasia were positive for CK20, CDX2, and MUC2, whereas cases with pyloric gland were positive for MUC6. MUC1, CEA and B72.3 were positive only in carcinoma. There was a trend toward increasing p53 and ki-67 from metaplasia to BilIN to carcinoma. 4/5 patients with carcinoma died and one was alive with disease. All others were free of disease except for one who developed new cysts. CDCs are associated with a high rate of BilIN (28.5%) and carcinoma (14.3%). CDCs show a sequence of tumor progression from metaplasia to BilIN and carcinoma.
    Human pathology 01/2014; · 3.03 Impact Factor
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    ABSTRACT: ARID1A, a chromatin remodeling gene recently discovered to be a tumor suppressor in ovarian cancers, has been found to be mutated at low frequencies in many other tumors including colorectal carcinoma (CRC). An association between ARID1A alteration and DNA mismatch repair (MMR) deficiency has been implicated; understanding this association may facilitate the understanding of the role of ARID1A in the various tumors. In this pilot study, we analyzed the immunohistochemical expression of ARID1A in a consecutive series of 257 CRCs that fulfilled a set of relaxed criteria for Lynch-syndrome screening; 59 (23%) were MMR-deficient by immunohistochemistry (44 MLH1/PMS2-deficient, 9 MSH2/MSH6-deficient, 4 MSH6-deficient, and 2 PMS2-deficient). ARID1A loss was observed in 9% (22/257) of the cohort: 24% of MMR-deficient tumors (14/59, 13 of the 14 being MLH1/PMS2-deficient) and 4% of MMR-normal tumors (8/198) (p < 0.05). MLH1 promoter hypermethylation was observed in 10 of the 13 MLH1/PMS2-deficient/ARID1A-loss tumors, indicating an association between ARID1A loss and sporadic microsatellite unstable CRCs. Among the MMR-deficient cases, ARID1A loss correlated with old age (p = 0.04), poor tumor differentiation (p < 0.01), medullary histology (p < 0.01), and an increased rate of nodal and distant metastasis (p = 0.03); these patients also trended towards a worse 5-year overall survival. Among MMR-normal tumors, no differences in clinicopathologic features were detected between the groups stratified by ARID1A. In conclusion, our results suggest that ARID1A loss may be linked to a specific subset of sporadic microsatellite unstable CRCs that may be medullary but are likely to present with metastatic disease, warranting further investigation.
    Human pathology 01/2014; · 3.03 Impact Factor
  • Ralph H. Hruban, David S. Klimstra
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    ABSTRACT: Infiltrating ductal adenocarcinoma of the pancreas is a real enigma. On one hand it is one of the most deadly of all of the solid malignancies. On the other, the neoplastic glands can be remarkably well-differentiated and it can be difficult to distinguish between a reactive non-neoplastic gland and a gland of invasive adenocarcinoma. In this review we will present diagnostic criteria that one can “hang your hat on” when establishing the diagnosis of infiltrating ductal adenocarcinoma of the pancreas. We will also review clinically important features of the disease, and, with the impending incorporation of molecular genetics into everyday practice, we will emphasize clinical applications of cancer genetics.
    Seminars in Diagnostic Pathology 01/2014; · 1.62 Impact Factor
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    ABSTRACT: Genetically engineered mouse models (GEMMs) have greatly expanded our knowledge of pancreatic ductal adenocarcinoma (PDAC) and serve as a critical tool to identify and evaluate new treatment strategies. However, the cost and time required to generate conventional pancreatic cancer GEMMs limits their use for investigating novel genetic interactions in tumor development and maintenance. To address this problem, we developed flexible embryonic stem cell (ESC)-based GEMMs that facilitate the rapid generation of genetically defined multiallelic chimeric mice without further strain intercrossing. The ESCs harbor a latent Kras mutant (a nearly ubiquitous feature of pancreatic cancer), a homing cassette, and other genetic elements needed for rapid insertion and conditional expression of tetracycline-controlled transgenes, including fluorescence-coupled shRNAs capable of efficiently silencing gene function by RNAi. This system produces a disease that recapitulates the progression of pancreatic cancer in human patients and enables the study and visualization of the impact of gene perturbation at any stage of pancreas cancer progression. We describe the use of this approach to dissect temporal roles for the tumor suppressor Pten and the oncogene c-Myc in pancreatic cancer development and maintenance.
    Genes & development 01/2014; 28(1):85-97. · 12.08 Impact Factor
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    ABSTRACT: Pancreatic carcinomas with acinar differentiation, including acinar cell carcinoma, pancreatoblastoma, and carcinomas with mixed differentiation, are distinct pancreatic neoplasms with poor prognosis. Although recent whole exome sequencing analyses have defined the somatic mutations that characterize the other major neoplasms of the pancreas, the molecular alterations underlying pancreatic carcinomas with acinar differentiation remain largely unknown. In the current study, we sequenced the exomes of 23 surgically resected pancreatic carcinomas with acinar differentiation. These analyses revealed a relatively large number of genetic alterations at both the individual base pair and chromosomal levels. There was an average of 119 somatic mutations per carcinoma. When three outliers were excluded, there was an average of 64 somatic mutations per tumor (range 12-189). The mean fractional allelic loss (FAL) was 0.27 (range 0-0.89) and heterogeneity at the chromosome level was confirmed in selected cases using fluorescent in situ hybridization (FISH). No gene was mutated in >30% of the cancers. Genes altered in other neoplasms of the pancreas were occasionally targeted in carcinomas with acinar differentiation; SMAD4 was mutated in six tumors (26%), TP53 in three (13%), GNAS in two (9%), RNF43 in one (4%) and MEN1 in one tumor (4%). Somatic mutations were identified in genes in which constitutional alterations are associated with familial pancreatic ductal adenocarcinoma, such as ATM, BRCA2, and PALB2 (one tumor each), as well as in genes altered in extra-pancreatic neoplasms, such as JAK1 in four tumors (17%) BRAF in three (13%), RB1 in three (13%), APC in two (9%), PTEN in two (9%), ARID1A in two (9%), MLL3 in two (9%), and BAP1 in one (4%). Perhaps most importantly, we found that more than a third of these carcinomas have potentially targetable genetic alterations including mutations in BRCA2, PALB2, ATM, BAP1, BRAF and JAK1.
    The Journal of Pathology 11/2013; · 7.59 Impact Factor
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    ABSTRACT: Well-differentiated neuroendocrine tumors metastasize to the skin uncommonly, and only 35 cases are reported in the literature. In only five of these patients, cutaneous metastases were the presenting symptom of malignancy; herein we report four such cases. Two patients were female and two male, aged 50 to 74 years (mean: 64.5 years), each with a solitary painless, slowly-enlarging, non-ulcerated cutaneous nodule of 3 to 12 months duration (mean: 9 months). The lesions were on the scalp (n = 3) and trunk (n = 1), and ranged in greatest dimension from 0.5 to 2.5 cm. The distinction from other microscopically similar entities, and the interpretation of origination from gastrointestinal, pancreatic or respiratory system primaries, was made clinically, or was based on the morphologic features and the immunohistochemical profile. One patient died of the disease progression after 36 months while two patients are alive with significant disease progression after 24 and 60 months. Metastatic neuroendocrine tumor should be considered in the differential diagnosis of cutaneous tumors with neuroendocrine morphology even in patients with no known history of visceral malignancy.
    Journal of Cutaneous Pathology 11/2013; · 1.77 Impact Factor
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    ABSTRACT: Through exomic sequencing of 32 intrahepatic cholangiocarcinomas, we discovered frequent inactivating mutations in multiple chromatin-remodeling genes (including BAP1, ARID1A and PBRM1), and mutation in one of these genes occurred in almost half of the carcinomas sequenced. We also identified frequent mutations at previously reported hotspots in the IDH1 and IDH2 genes encoding metabolic enzymes in intrahepatic cholangiocarcinomas. In contrast, TP53 was the most frequently altered gene in a series of nine gallbladder carcinomas. These discoveries highlight the key role of dysregulated chromatin remodeling in intrahepatic cholangiocarcinomas.
    Nature Genetics 11/2013; · 35.21 Impact Factor
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    ABSTRACT: Cholangiocarcinoma is the second most common primary liver cancer and responds poorly to existing therapies. Intrahepatic cholangiocarcinoma (ICC) likely originates from the biliary tree and develops within the hepatic parenchyma. We have generated a flexible orthotopic allograft mouse model of ICC that incorporates common genetic alterations identified in human ICC and histologically resembles the human disease. We examined the utility of this model to validate driver alterations in ICC and tested their suitability as therapeutic targets. Specifically, we showed that the fused-in-glioblastoma-c-ros-oncogene1 (FIG-ROS1(S); FIG-ROS) fusion gene dramatically accelerates ICC development and that its inactivation in established tumors has a potent antitumor effect. Our studies establish a versatile model of ICC that will be a useful preclinical tool and validate ROS1 fusions as potent oncoproteins and therapeutic targets in ICC and potentially other tumor types.
    Proceedings of the National Academy of Sciences 10/2013; · 9.81 Impact Factor
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    ABSTRACT: The grading system for pancreatic neuroendocrine tumors (PanNETs) adopted in 2010 by the World Health Organization (WHO) mandates the use of both mitotic rate and Ki67/MIB-1 index in defining the proliferative rate and assigning the grade. In cases when these measures are not concordant for grade, it is recommended to assign the higher grade, but specific data justifying this approach do not exist. Thus, we counted mitotic figures and immunolabeled, using the Ki67 antibody, 297 WHO mitotic grade 1 and 2 PanNETs surgically resected at a single institution. We quantified the Ki67 proliferative index by marking at least 500 cells in "hot spots" and by using digital image analysis software to count each marked positive/negative cell and then compared the results with histologic features and overall survival. Of 264 WHO mitotic grade 1 PanNETs, 33% were WHO grade 2 by Ki67 proliferative index. Compared with concordant grade 1 tumors, grade-discordant tumors were more likely to have metastases to lymph node (56% vs. 34%) (P<0.01) and to distant sites (46% vs. 12%) (P<0.01). Discordant mitotic grade 1 PanNETs also showed statistically significantly more infiltrative growth patterns, perineural invasion, and small vessel invasion. Overall survival was significantly different (P<0.01), with discordant mitotic grade 1 tumors showing a median survival of 12 years compared with 16.7 years for concordant grade 1 tumors. Conversely, mitotic grade 1/Ki67 grade 2 PanNETs showed few significant differences from tumors that were mitotic grade 2 and either Ki67 grade 1 or 2. Our data demonstrate that mitotic rate and Ki67-based grades of PanNETs are often discordant, and when the Ki67 grade is greater than the mitotic grade, clinical outcomes and histopathologic features are significantly worse than concordant grade 1 tumors. Patients with discordant mitotic grade 1/Ki67 grade 2 tumors have shorter overall survival and larger tumors with more metastases and more aggressive histologic features. These data strongly suggest that Ki67 labeling be performed on all PanNETs in addition to mitotic rate determination to define more accurately tumor grade and prognosis.
    The American journal of surgical pathology 10/2013; · 4.06 Impact Factor
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    ABSTRACT: Radiofrequency (RF) ablation (RFA) is a minimally invasive treatment for colorectal-cancer liver metastases (CLM) in selected nonsurgical patients. Unlike surgical resection, RFA is not followed by routine pathological examination of the target tumor and the surrounding liver tissue. The aim of this study was the evaluation of apoptotic events after RFA. Specifically, we evaluated YO-PRO-1 (YP1), a green fluorescent DNA marker for cells with compromised plasma membrane, as a potential, early marker of cell death. YP1 was applied on liver tissue adherent on the RF electrode used for CLM ablation, as well as on biopsy samples from the center and the margin of the ablation zone as depicted by dynamic CT immediately after RFA. Normal pig and mouse liver tissues were used for comparison. The same samples were also immunostained for fragmented DNA (TUNEL assay) and for active mitochondria (anti-OxPhos antibody). YP1 was also used simultaneously with propidium iodine (PI) to stain mouse liver and samples from ablated CLM. Following RFA of human CLM, more than 90 % of cells were positive for YP1. In nonablated, dissected pig and mouse liver however, we found similar YP1 signals (93.1 % and 65 %, respectively). In samples of intact mouse liver parenchyma, there was a significantly smaller proportion of YP1 positive cells (22.7 %). YP1 and PI staining was similar for ablated CLM. However in dissected normal mouse liver there was initial YP1 positivity and complete absence of the PI signal and only later there was PI signal. Conclusion: This is the first time that YP1 was applied in liver parenchymal tissue (rather than cell culture). The results suggest that YP1 is a very sensitive marker of early cellular events reflecting an early and widespread plasma membrane injury that allows YP1 penetration into the cells.
    Cytotechnology 09/2013; · 1.32 Impact Factor

Publication Stats

16k Citations
2,061.26 Total Impact Points


  • 1995–2014
    • Memorial Sloan-Kettering Cancer Center
      • • Department of Surgery
      • • Department of Pathology
      • • Hepatopancreatobiliary Service
      New York City, New York, United States
  • 2013
    • Penn State Hershey Medical Center and Penn State College of Medicine
      • Department of Pathology
      Hershey, Pennsylvania, United States
  • 2005–2013
    • University of Massachusetts Medical School
      • Program in Gene Function and Expression
      Worcester, Massachusetts, United States
    • Christian-Albrechts-Universität zu Kiel
      • Institute for General Microbiology
      Kiel, Schleswig-Holstein, Germany
  • 2012
    • University of Pennsylvania
      • Division of Gastroenterology
      Philadelphia, PA, United States
    • Weill Cornell Medical College
      • Department of Pathology and Laboratory Medicine
      New York City, NY, United States
  • 2011
    • San Antonio Military Medical Center
      Texas City, Texas, United States
    • University of Illinois at Chicago
      • Department of Surgery (Chicago)
      Chicago, IL, United States
    • Mount Sinai Medical Center
      New York City, New York, United States
    • University of Texas Southwestern Medical Center
      • Department of Pathology
      Dallas, TX, United States
  • 2010
    • Roger Williams University
      Bristol, Rhode Island, United States
    • Louisiana State University Health Sciences Center New Orleans
      • Department of Surgery
      Baton Rouge, LA, United States
    • Technische Universität München
      München, Bavaria, Germany
    • Rutgers New Jersey Medical School
      • Cancer Institute of New Jersey
      Newark, NJ, United States
    • University of Virginia
      Charlottesville, Virginia, United States
  • 2004–2010
    • Cornell University
      • • Department of Pathology and Laboratory Medicine
      • • Department of Medicine
      Ithaca, NY, United States
    • Academisch Medisch Centrum Universiteit van Amsterdam
      • Department of Pathology
      Amsterdam, North Holland, Netherlands
  • 2008
    • University of Wisconsin–Madison
      • Department of Surgery
      Madison, Wisconsin, United States
  • 2007
    • Tel Aviv University
      Tell Afif, Tel Aviv, Israel
  • 2000–2007
    • Karmanos Cancer Institute
      • Division of Hematology and Oncology
      Detroit, Michigan, United States
  • 2000–2006
    • Wayne State University
      • Department of Pathology
      Detroit, MI, United States
  • 1998–2006
    • Johns Hopkins Medicine
      • Department of Pathology
      Baltimore, MD, United States
  • 1992–2005
    • Yale-New Haven Hospital
      • Department of Pathology
      New Haven, Connecticut, United States
  • 2002
    • University of Verona
      • Department of Pathology
      Verona, Veneto, Italy
    • Johns Hopkins University
      • Department of Pathology
      Baltimore, MD, United States
  • 1999
    • City of Hope National Medical Center
      Duarte, California, United States
  • 1997
    • University of Iowa
      • Department of Surgery
      Iowa City, IA, United States
  • 1994
    • CUNY Graduate Center
      New York City, New York, United States
  • 1993
    • Devry College of New York, USA
      New York City, New York, United States