David S. Klimstra

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Pancreatic neuroendocrine tumors (PanNETs) are a rare but clinically important form of pancreatic neoplasia. To explore the genetic basis of PanNETs, we determined the exomic sequences of 10 nonfamilial PanNETs and then screened the most commonly mutated genes in 58 additional PanNETs. The most frequently mutated genes specify proteins implicated in(More)
Neuroendocrine tumors (NETs) arise in most organs of the body and share many common pathologic features. However, a variety of different organ-specific systems have been developed for nomenclature, grading, and staging of NETs, causing much confusion. This review examines issues in the pathologic assessment of NETs that are common among primaries of(More)
OBJECTIVE To analyze resectability and survival in patients with hilar cholangiocarcinoma according to a proposed preoperative staging scheme that fully integrates local, tumor-related factors. SUMMARY BACKGROUND DATA In patients with hilar cholangiocarcinoma, long-term survival depends critically on complete tumor resection. The current staging systems(More)
We have examined the microscopic appearance, immunohistochemical staining properties, and clinical behavior of 28 cases of acinar cell carcinoma of the pancreas. Two of the tumors occurred in children. The adult patients ranged in age from 40 to 81 years (mean, 62 years). Males greatly outnumbered females, and most of the patients were white. Presenting(More)
BACKGROUND Despite data suggesting a rising worldwide incidence, intrahepatic cholangiocarcinoma (IHC) remains an uncommon disease. This study analyzes changes in IHC frequency, demographics, and treatment outcome in a consecutive and single institutional cohort. METHODS Consecutive patients with confirmed IHC seen and treated over a 16-year period were(More)
To investigate the role of an activated K-Ras gene in the initiation and maintenance of lung adenocarcinomas, we developed transgenic mice that express murine K-Ras4b(G12D) under the control of doxycycline in type II pneumocytes. Focal proliferative lesions of alveolar type II pneumocytes were observed as early as seven days after induction with(More)
PURPOSE To establish evidence of activity, or lack thereof, of cetuximab-based therapy in patients with refractory colorectal cancer with tumors that do not demonstrate epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC). PATIENTS AND METHODS Pharmacy computer records were reviewed to identify all patients who received(More)
Background: Solid-pseudopapillary tumors (SPTs) of the pancreas have been reported as rare lesions with “low malignant potential” occurring mainly in young women. This study was designed to define the clinicopathological characteristics and the effect of surgical intervention. Methods: A retrospective review from January 1985 to July 2000 was performed.(More)
Approximately 130,000 cases of colorectal cancer (CRC) are diagnosed in the United States each year, and about 15% of these have a hereditary component. Two well-defined syndromes, familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC), account for up to 5% of the total new cases of CRC. Truncating APC mutations are(More)
BACKGROUND Tumors with combined hepatocellular and cholangiocellular features are well known histopathologically but their clinical behavior is poorly understood. The objectives of the current study were to define the demographic profile of the patients in whom these uncommon tumors occur and to evaluate treatment outcome in comparison with that in patients(More)