Proteomic classification of pancreatic adenocarcinoma tissue using protein chip technology

BACKGROUND & AIMS: Pancreatic adenocarcinoma is a most devastating cancer that presents late and is rapidly progressive. This study aimed to identify unique, tissue-specific protein biomarkers capable of differentiating pancreatic adenocarcinoma (PC) from adjacent uninvolved pancreatic tissue (AP), benign pancreatic disease (B), and nonmalignant tumor tissue (NM). METHODS: Tissue samples representing PC (n = 31), AP (n = 44), and B (n = 19) tissue were analyzed on hydrophobic protein chip arrays by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Training models were developed using logistic regression and validated using the 10-fold cross-validation approach. RESULTS: The hydrophobic protein chip array revealed 13 protein peaks differentially expressed between PC and AP (receiver operating characteristic [ROC] area under the curve [AUC], 0.64-0.85), 8 between PC and B (ROC AUC, 0.67-0.78), and 12 between PC and NM tissue (ROC AUC, 0.63-0.81). Logistic regression and cross-validation identified overlapping panels of peaks to develop a training model that distinguished PC from AP (77.4% sensitivity, 84.1% specificity), B (83.9% sensitivity, 78.9% specificity), and NM tissue (58.1% sensitivity, 90.5% specificity). The final panels selected correctly classified 80.6% of PC and 88.6% of AP samples (ROC AUC, 0.92), 93.5% of PC and 89.5% of B samples (ROC AUC, 0.99), and 71.0% of PC and 92.1% of NM samples (ROC AUC, 0.91). CONCLUSIONS: This study used surface-enhanced laser desorption/ionization time-of-flight mass spectrometry to discover a number of protein panels that can distinguish effectively between pancreatic adenocarcinoma, benign, and adjacent pancreatic tissue. Identification of these proteins will add to our understanding of the biology of pancreatic cancer. Furthermore, these protein panels may have important diagnostic implications.     

Endobronchial ultrasound

During flexible fiberoptic bronchoscopy (FB), a solitary pulmonary nodule (SPN) is sampled by means of transbronchial needle aspiration (TBNA), brush, or transbronchial lung biopsy under fluoroscopy; and mediastinal lymph nodes are sampled using "blind" TBNA. Endobronchial ultrasound (EBUS) was developed to help visualize the lesion at the time of biopsy in order to improve the diagnostic yield. METHODS: There are two types of EBUS techniques: using a radial probe (RP) with a rotating transducer at the distal tip, which produces a 360 degrees image to the long axis of the bronchoscope; and using an EBUS bronchoscope with a linear transducer at its distal tip, producing a 50 degrees image parallel to its long axis. RESULTS: In biopsies of SPNs < 2 cm using an RP, EBUS demonstrates a higher diagnostic yield than conventional FB techniques. With mediastinal and hilar nodal stations, except for the subcarina, EBUS shows a higher yield over blind TBNA. The current procedural terminology code for EBUS is 31620, a "ZZZ" code submitted in addition to other performed procedures (31622-31638). In 2007, an estimate of physician Medicare reimbursement for EBUS is $70.49. Reimbursement is locality dependent and based on economic-exchange conversion factors. Incorporating an ultrasound image into the report substantiates the use of this technique. Limitations: The physician must learn ultrasound image interpretation and the EBUS technique, and be skilled in TBNA. Maintaining competency requires frequent performance of EBUS. CONCLUSION: EBUS-directed biopsy improves the yield over conventional FB for SPNs < 2 cm and for most mediastinal or hilar nodal stations. This reduces the need to conduct additional diagnostic procedures.     

Epidermoid cyst in intrapancreatic accessory spleen: A systematic review

Background/Objectives

Due to its rarity, epidermoid cyst in intrapancreatic accessory spleen (ECIPAS) is still a diagnostic dilemma during clinical practice. The aim of this review was to summarize the epidemiologic features and management of ECIPAS.

Genetic markers differentiating follicular thyroid carcinoma from benign lesions

Thyroid nodules are commonly encountered during routine medical care. The main problem established by a discovery of a thyroid nodule is to discriminate between a benign and malignant lesion. Fine-needle aspiration (FNA) is the most widely used and cost-effective preoperative test for initial evaluation of a thyroid nodule. While the overall accuracy of FNA for classical papillary thyroid carcinoma (PTC) approaches 100%, it has limited accuracy with follicular lesions. Patients with a cytological report of indeterminate or follicular lesions are referred to surgery for a more accurate diagnosis. A more acute molecular-based test for thyroid nodules is needed not only to improve treatment decisions, but also to potentially reduce the long-term health costs. Several studies have looked into biologic markers that could be used as an adjuvant to distinguish the benign from malignant nodules. This review will focus on those biomarkers that are potentially useful in the diagnosis of thyroid lesions commonly classified as indeterminate.     

SUCCESSFUL ENDOSCOPIC ULTRASOUND‐GUIDED FINE‐NEEDLE ASPIRATION OF THE PELVIC LESION THROUGH THE SIGMOID COLON

Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) is a useful modality when the target is a lymph node located in the mediastinum, perigastric area or perirectum. Although it is difficult to carry out EUS‐FNA of the colon using an oblique view linear scope, we report two cases of successful EUS‐FNA of the lesions via the proximal sigmoid colon using a recently available new convex type EUS scope. Case 1 was a 77‐year‐old Japanese woman noted to have multiple lymph node swelling in the para‐aortic area and in the pelvis. Case 2 was a 60‐year‐old Japanese woman noted to have a large mass in the left lower abdomen. In case 1, oral EUS showed no lymph node swelling. In both cases, EUS with forward‐viewing radial echoendoscope was carried out via the anus, and multiple lymph‐node swelling or a large mass was observed near the proximal sigmoid colon. In the EUS‐FNA for these cases, we used a new convex‐type EUS scope that has an oblique view, but with a wide‐angled optical device giving a view similar to a forward one. EUS‐FNA was successfully carried out on the lesions. The pathological specimen revealed diffuse large B‐cell lymphoma in case 1 and gastrointestinal stromal tumor (GIST) in case 2.     

TRANSGASTRIC TRANSHEPATIC ENDOSONOGRAPHY‐GUIDED BILIARY DRAINAGE: HISTOLOGICAL ASSESSMENT OF ITS SINUS TRACT IN AN AUTOPSY CASE

Endosonography‐guided biliary drainage (ESBD) is gaining attention as a promising drainage technique for obstructive jaundice. However, histological changes resulting from ESBD have not been well understood. We had an opportunity to histologically investigate the influence of ESBD, established between the left hepatic duct and the stomach, on the relevant organs in an autopsy case with bile duct cancer extending from the pancreatic head to the hepatic hilum with duodenal invasion. Localized fibrous connective tissues were present around and along the sinus tract, including the connection between the surfaces of the left lobe of the liver and the gastric serosa, without hemorrhage, inflammatory changes, or cancer invasion. The inside of the ESBD stent was slightly stenotic at the intramural portion of the stomach due to proliferation of granulation tissue. No bile stasis or abscess was observed in the left lobe. These results are quite suggestive of the high safety and efficacy of ESBD with adequate performance.     

Complications of diagnostic and therapeutic Endoscopic Ultrasound

Endoscopic Ultrasound (EUS) provides the unique opportunity to visualize, interrogate and intervene gastrointestinal (GI) luminal, mural or peri-luminal structures and pathology with negligible adverse effects. Diagnostic, upper GI and rectal EUS is feasible, extremely safe, and efficacious. Most EUS guided interventions are safe, effective and minimally invasive, compared to peers in the percutaneous radiological or surgical procedures.As with any endoscopic procedure, EUS and its guided interventions may be accompanied by adverse events. EUS related complications are generally infrequent in expert hands, and mainly include bleeding and perforation. However, the nature and severity of adverse events associated with each EUS guided procedure are unique. Hence, it is paramount for endosonographer to have sufficient knowledge of the indications, techniques, and potential risks involved before contemplating any given procedure.Most common intervention with EUS is transmural fine needle aspiration (FNA), which is an extremely safe procedure. EUS guided drainage procedures are rapidly evolving with newer devices and methods being employed. Among them, EUS guided drainage of pancreatic fluid collection-pseudocyst or walled off necrosis (WON), has largely replaced other methods (surgical, percutaneous or non-EUS endoscopic) with acceptable complications. Currently, dedicated metal stents are more widely used compared to plastic stents for drainage of PFC, especially WON. EUS has made a definite impact in biliary access and drainage of obstructed biliary system, in patients where ERCP has failed or is technically not possible, closely competing with percutaneous biliary drainage. In spite of some complications, recent improvement in devices for bilio-enteric fistula creation and stent designs, has added to its safety and efficacy. EUS guided pancreatic duct drainage remains the most challenging of EUS guided interventions where in-roads are being made.