Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sampling Errors”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
PubMed2000

Value of ultrasound-guided fine-needle aspiration biopsy of thyroid nodules in an endemic goitre area.

The aim of this study was to determine the value, advantages and limitations of ultrasound-guided fine-needle aspiration biopsy (US-FNAB) in an endemic goitre area. US-FNAB was performed on all outpatients who presented with hypoechoic and/or hypofunctional and/or growing nodules. A total of 4518 US-FNABs were performed and 718 patients from this series underwent surgery. Cytological results of the primarily performed US-FNAB of these patients were compared retrospectively with the histological results. US-FNAB results were grouped as (1) non-malignant (n = 303), (2) non-malignant follicular proliferation (n = 177), (3) malignancy cannot be ruled out (n = 133), (4) malignant (n = 61), (5) inadequate (n = 34), and (6) sampling error; biopsy of a non-malignant nodule (n = 10). Nodules as small as 5 mm in diameter could be biopsied, gaining representative material. US-FNAB found a malignant or suspicious cytology in 65 out of 87 cases with malignant histology (74.71%). Diagnosis of early tumour stages was often possible: 12 of 18 thyroid carcinomas biopsied and smaller than 10 mm in diameter had malignant or suspicious cytology (groups 3 and 4). US-FNAB was performed incorrectly within non-malignant nodules in ten patients (1.39%) with multinodular goitre (ten papillary carcinomas, nine smaller than 10 mm). Regarding the cytology of groups 1 and 2 as benign and those of groups 3 and 4 as malignant, US-FNAB performance was as follows: sensitivity 87.84%, specificity 78.50%, negative predictive values 98.13%, positive predictive values 33.51% and accuracy 79.53%. Biopsies with inadequate material were obtained in 4.73% of all biopsies. No major adverse effects occurred. Re-biopsies in 61 cases did not alter the cytological outcome in those cases where adequate material was obtained. US-FNAB is a valuable method in the pre-operative assessment of thyroid nodules in order to select patients for surgery, as malignancy can often be detected even in early tumour stages. However, even with ultrasonographic guidance, the minimal tumour size detectable by US-FNAB is around 5 mm. The cytological interpretation in cases with regression and microfollicular proliferation also sets limits on the method. However, patients with non-malignant cytologies can be followed up safely by sonography due to the high NPV of US-FNAB as long as thyroid nodules do not become larger. Re-biopsies seem to be of limited value as long as adequate material was obtained by US-FNAB.

Adenocarcinoma, Follicular↗
PubMed2000

Detection of viral and bacterial protein in endomyocardial biopsies of patients with inflammatory heart muscle disease?

The development of highly sensitive molecular biological methods such as in-situ hybridization and polymerase chain reaction (PCR) made it possible to detect viral/bacterial nucleic acid in human endomyocardial biopsies. However, only a few investigations addressed the problem of latent persistence of viral and bacterial genome and the detection of the corresponding proteins, which could have important consequences for the clinical course of the disease. The purpose of this study was to determine whether protein of various viruses (adenovirus, enterovirus, cytomegalovirus, influenza A and B virus, herpes simplex virus 1 and 2) and bacteria (chlamydia pneumonia) can be detected in endomyocardial biopsies of patients with myocarditis and dilated cardiomyopathy with and without inflammation by use of an immunofluorescence assay and to compare the frequency of its detection with the results of PCR, immunohistology and serology. Thirty-nine patients with myocarditis and dilated cardiomyopathy with and without inflammation were examined by a direct immunofluorescence assay using the endomyocardial biopsy as antigen. Each of the samples was additionally studied by immunohistological methods and PCR for the detection of infiltrating cells and the genome of cardiotropic viruses or bacteria. Fourteen of patients were considered to have myocarditis (group 1), 9 dilated cardiomyopathy with inflammation (group 2), 10 dilated cardiomyopathy (group 3), 6 to have no myocarditis or dilated cardiomyopathy (group 4). Using a direct immunofluorescence assay we could show only that 1 patient without histological myocarditis or dilated cardiomyopathy (group 4) was positive for influenza B and chlamydia pneumonia antigens in the endomyocardial biopsy. In addition we have determined influenza B-specific antibodies, such as IgG (marginal titer) and IgA (high titer) and chlamydia pneumonia-specific antibodies, such as IgG (marginal titer) in serum of this patient. A second patient with dilated cardiomyopathy was found to be positive for protein of chlamydia pneumonia, who was shown to have chlamydia pneumonia-specific antibodies, such as IgG (high titer) in serum. There was no correlation with PCR results, but good correlation with influenza B and chlamydia pneumonia-specific antibodies in sera of these patients. In this investigation we have determined viral/bacterial-specific antibodies using serological methods and proteins of these agents using immunoflourescence. Despite the detection of virus or bacteria-specific antibodies in the sera and detection of viral and/or bacterial protein in the biopsies of some of the patients viral and/or bacterial genome was not found in the biopsy. This may be explained by the focal character of myocarditis and sampling error, because for technical reasons we use different biopsies for immunohistochemical and molecular biological investigations.

Adult↗
PubMed2005

[Indication for myocardial biopsy in myocarditis and dilated cardiomyopathy].

This review may serve as a basis for evaluating publications on the topic "myocardial biopsy for myocarditis and dilated cardiomyopathy" in the clinical practice. The literature is particularly analyzed to answer the question, whether an endomyocardial catheter biopsy is indicated in patients with these myocardial disorders in the clinical routine besides its unequivocal scientific value. The judgment of the biopsy samples has been based on the classically histological and for years on the additional immunohistochemical and molecular biological-virological examination. The analysis of the literature data shows that outside scientific studies there is no indication to perform myocardial biopsy, or in other words, this procedure is not suitable for diagnosis, therapy, detection of early stages or prognostic evaluation in the disease spectrum "myocarditis, inflammatory heart disease, dilated cardiomyopathy". Reasons are the subjectivity in the judgment and interpretation of bioptic findings resulting in considerable interobserver variability, a missing standardization in biopsy performance, methods of examination and diagnostic criteria, the bioptic sampling error, missing therapeutic and prognostic consequences and potentially severe complications in performing myocardial biopsies. So far, the specificity of inflammatory changes in patients with dilated cardiomyopathy has not been proven in controlled blinded studies. The bioptic changes could be understood also as an unspecific inflammatory process in front of increasing pathophysiological evidence for myocardial inflammation in any form of heart failure. In addition, regarding the specific etiology of dilated cardiomyopathy, primarily a genetic, noninfectious or autoimmunologic origin plays an increasing role. The favorable clinical course and the very good prognosis of the acute, clinically diagnosed or supposed viral myocarditis should also be taken into account for the evaluation of myocardial biopsy. It should also be considered that the proof of causality between acute myocarditis and dilated cardiomyopathy is still lacking. Regarding the diagnosis "inflammatory cardiomyopathy" and multiple inflammatory subsets among patients with dilated cardiomyopathy or unclear regional contraction disorder, there is no adequate clinical validation of different diagnostic methods, criteria and interpretations so far. It is missleading to replace the well-established clinical diagnosis myocarditis by the bioptic diagnosis "inflammatory cardiomyopathy". However, endomyocardial catheter biopsy is clearly indicated in rare patients with fulminant myocarditis, giant-cell myocarditis and myocardial storage disease. Its probably underestimated role in sarcoid heart disease still needs to be clarified by systematic studies.

Acute Disease↗
PubMed2001

[Differential diagnostic problems in assessment of benign bone tumors].

The diagnosis of benign bone tumors can cause many problems and a definitive histological diagnosis is often impossible without the knowledge of clinical datas, age of the patient and anatomical location of the tumor. Therefor cooperation between pathologist, orthopedic surgeon and radiologist is necessary, to reduce the risk of misinterpretation of benign and malignant bone tumors. Benign bone tumors often show a heterogenous histology and overlapping morphology between different entities has to be kept in mind, as well as the sampling error in biopsy- and frozen section material. In most cases the pathologist has to rely on conventional stainings because the immunohistochemistry stainings are often not helpful.

Adolescent↗
PubMed2004

The establishment of 'essential derivation' among rose varieties, using AFLP.

In the International Union for the Protection of New Varieties of Plants Act of 1991, mutation is mentioned as one of the mechanisms to obtain an 'essentially derived' variety (EDV). For the implementation of the EDV concept in the case of mutation, it is important that the level of genetic relatedness between an initial variety and derived mutant varieties can clearly be distinguished from the level of relatedness between arbitrary pairs of varieties without a derivation relation. Conditions to be fulfilled for such a distinction include enough genetic differentiation in the germplasm pool of interest, sufficiently low levels of genomic sampling error and technical laboratory error and high reproducibility within and between laboratories. In rose, mutants or 'sports' are frequently observed during multiplication, making it a suitable crop for studying the possibilities for introduction of the EDV concept in ornamentals. We studied genetic similarities among 83 rose varieties, including 13 mutant groups. Twelve AFLP primer combinations generated 284 polymorphic markers and 114 monomorphic (fixed) bands. Pair-wise Jaccard similarities between original varieties and derived mutants were close to 1.0 (>0.96), whereas all similarities between original varieties were below 0.80, with 75% of the non-mutant similarities even being below 0.50. Values less than 1.0 for similarity among original varieties and their mutants were to a major extent due to scoring errors. Error rates in automated scoring proved to be lower than those in manually scored and transferred data. Experimental errors, even between laboratories, turned out to be very small. On the basis of a consistent and large difference between similarities, relations between an original variety and its mutants can easily be identified and distinguished from relations between original varieties. These results open the way for implementing the essential derivation concept in rose.

Breeding↗
PubMed2001

Predictive elements in ocular interception and tracking of a moving target by untrained cats.

We presented a mechanical target moving at constant velocity to awake, nontrained, head-restrained cats, in order to study how naive animals pursue objects moving at a high speed with their gaze. Eye movements were recorded while the target was moving in different directions at a constant velocity (20-80 degrees/s) through the center of the visual field. We observed two oculomotor strategies: cats either made an interception saccade (IS) toward the target but opposite to its motion, or tracked it in the direction of motion. They used the interception strategy more frequently when the gaze position error at the onset of target motion was large, and the tracking strategy when it was small. Interception was always achieved by single saccades, which were faster than tracking saccades (TS). During tracking, cats generated sequences of two to six saccades separated by "smooth" eye movements. Tracking quality varied considerably from trial to trial. When the level of motivation was high, cats would track the target at 80 degrees/s over up to 75% of the oculomotor range, with relatively small position errors. We compared ISs and TSs with respect to their metric properties and timing. The amplitudes of ISs positively correlated with position error existing 100 ms before saccade onset, but saccade vectors were directed to a point ahead of the target along the target's track. We conclude that, in programming the ISs, target motion is used to predict the future target position so as to assure a spatial lead of the gaze at the saccade end, instead of attempting a precise capture of the target. The amplitude of TSs did not depend on preceding position errors. TSs were usually small at the onset of the first saccade, as if cats would wait till the target arrived near the line of sight. A majority of primary TSs were initiated before the target arrived near the direction of gaze. Thus they had a direction, opposite to the position error sampled 100 ms before the saccade, but the same as the direction of target motion. Prediction of the future target position from its velocity vector should therefore contribute to the programming of TSs. In addition, we observed that TSs were faster when they were initiated with a spatial lag relative to the target and they were slower if there was a spatial lead or target velocity was reduced. Such a modulation appears to be analogous to the predictive correction of the saccade amplitude during smooth pursuit in primates. Considering strong visual motion sensitivity and motor properties of output neurons of the superior colliculus, it is likely that, in cats, the colliculus makes a major contribution to the integration of eye movement-related and target motion-related signals.

Animals↗
PubMed2003

High grade dysplasia: surveillance, mucosal ablation, or resection?

Barrett's esophagus is a common premalignant condition that results from chronic gastroesophageal reflux. High grade dysplasia in the metaplastic esophagus is thought to be the last step in the metaplasia-to-carcinoma sequence that characterizes this disease. The management of high grade dysplasia in Barrett's esophagus is controversial. Some investigators advocate a rigorous endoscopic surveillance program with biopsies, but this approach has been questioned because of its clinical impracticality, high cost, possibility of sampling errors, and difficulty demonstrating effectiveness on a reproducible basis. Others advocate mucosal ablative therapy to eradicate the dysplastic and metaplastic epithelium. This approach, still in its infancy, cannot be accepted as standard therapy at the present time because of limited follow-up, its questionable ability to completely eradicate the abnormal mucosa, the phenomenon of pseudoregression, and the patients require continued rigorous endoscopic surveillance. Esophagectomy, on the other hand, can be accomplished with a low mortality rate in these patients. We advocate this approach because a large number of them have invasive cancer in the esophagus despite a preoperative diagnosis of only high grade dysplasia. In addition, the 5-year survival is excellent even if invasive cancer is present, and these patients are liberated from rigorous endoscopic surveillance for the rest of their lives. For patients with high grade dysplasia in Barrett's esophagus who are poor operative risks, less invasive approaches such as mucosal ablation may play a role, but longer follow-up information is needed before this technique can be accepted even in this setting.

Barrett Esophagus↗
PubMed1994

[The histological features of local recurrences of soft tissue sarcomas].

Local recurrence is a well-recognised problem in soft tissue sarcomas, especially at difficult anatomical locations or after inadequate surgery. It is logical to assume that such recurrence will have an adverse effect on prognosis. In most cases the histological appearance of the recurrence is very similar to that of the primary neoplasm, in view of the fact that recurrence is most common in high-grade (poorly differentiated) sarcomas. However, in some cases, the appearance may change in one of three ways: (1) Gradual progression in grade. This phenomenon is seen most often in leiomyosarcoma or myxofibrosarcoma, in which the tumour shows progressive loss of differentiation and there is increasing risk of metastasis; (2) Abrupt change to a higher grade. This phenomenon, known as dedifferentiation, is commonest (among soft tissue lesions) in liposarcoma and is characterised usually by the emergence of an "MFH-like" pattern and an increased risk of metastasis; (3) Acquisition of differentiation. Some round cell sarcomas in children become better differentiated after chemotherapy, and some dedifferentiated adult sarcomas may revert to their well-differentiated form; occasionally the appearance of greater differentiation reflects sampling error in the primary tumour. Pathologists should be aware that significant morphological changes may occur in recurrent soft tissue sarcomas and, in analysing and diagnosing such lesions, they should always review material from the primary tumour.

Cell Differentiation↗
PubMed1999

Epidermoid cysts of the pineal region.

Localization of epidermoid cysts to the pineal region is rare. The 7-year-old boy now reported presented with an 18-month history of progressive ataxia. CT and MRI scans demonstrated a 2.5x2.5 cm cyst at the pineal region with obstructive hydrocephalus. At surgery via an occipital transtentorial approach, a characteristic "pearly tumour" was encountered, and complete resection was achieved. We present the management of this child with pineal region epidermoid cyst and review 11 cases reported in the literature since 1968. In all, 8 of the 12 patients were males. The age at the time of diagnosis ranged from 7 years to 69 years. Parinaud's syndrome and hydrocephalus are the most common presenting findings. All but 1 patient underwent direct surgical resection; 1 had stereotactic decompression. Surgical treatment brought about complete resolution of the presenting symptoms and signs in 10 of the 12 cases. One patient had persistent upgaze palsy. One patient died from progression of the pineal region mass. This patient presented with hemiparesis, which is a marker of clinical aggressiveness. The authors advocate direct surgical attack as opposed to stereotactic diagnosis and aspiration to: (1) obtain maximal resection and thereby limit the potential for recurrence and delayed complications of the cyst; (2) possibly avoid shunt placement in patients who present with hydrocephalus; and (3) decrease the likelihood of sampling error.

Adolescent↗
PubMed1999

Surgery in the management of primary intracranial germ cell tumors.

Surgery plays an important part in the overall management of primary central nervous system (CNS) germ cell tumors. While the general surgical objectives in patients with these neoplasms are similar to those with other types of CNS tumors, to obtain an accurate histopathologic diagnosis and to contribute towards improving patient survival the unique features of germ cell tumors have necessitated novel treatment strategies. Pure germinomas are exquisitely radiosensitive, and prior studies have shown no survival benefit from radical resection of such lesions. However, a significant proportion of CNS GCTs contain admixtures of nongerminomatous GCT (NGGCT) elements and are less responsive to aggressive chemotherapy and irradiation. Biopsy of these malignant GCTs carries the risk of histologic sampling error. Nevertheless, a proportion of NGGCTs produce tumor markers detectable in serum or CSF and may be accurately diagnosed without surgical intervention. Although the role of radical surgical resection has not been definitively demonstrated in the literature, recent data from an international cooperative trial suggest a survival benefit from radical resection of localized NGGCTs. Lastly, increasing experience has supported the role of delayed resective ("second-look") surgery for patients with negative tumor markers but residual radiographic abnormalities after initial chemotherapy. Resection of such lesions has typically yielded necrosis or teratoma, which may be cured by surgical resection, and obviated the need for additional chemotherapy or irradiation.

Biomarkers, Tumor↗
PubMed2004

Relative expression of human telomerase catalytic subunit (hTERT) transcripts in astrocytic gliomas.

Human telomerase catalytic subunit (hTERT) expression has been reported as a marker for malignancy in various tumor systems. The aim of the present study was to investigate the relative expression of hTERT (relhTERT) and its transcripts A+B+ (contained in the full-length product), Adel and Bdel in astrocytic gliomas (grades I-IV, n=38). relhTERT was assessed by duplex reverse transcription-PCR and the expression profile of Adel, Bdel and A+B+ transcripts by nested real time-PCR. relhTERT and A+B+ presence correlated well with each other ( P<0.001) and with histological grading [grades I-II (low) vs III-IV (high), P(relhTERT)=0.002 and P(A+B+)<0.001]. A+B+ was detected in one out of seven hTERT-positive low-grade tumors, while it was present in 96.3%, and predominantly expressed in 59.3% of high-grade tumors. Bdel predominance was observed only in three cases, irrespective of grading, while Bdel levels equal or close to those of A+B+ were found in 30.4% of grade IV tumors. In situ hybridization with specific Bplus and Bdel probes revealed positive signals for both mRNAs in association with relhTERT and respective variant profiles. In addition, this method was useful in assessing hTERT expression in cases where sampling errors for RT-PCR were unavoidable. Our findings show that except for differences in relhTERT, low- and high-grade astrocytic gliomas exhibit distinct hTERT variant profiles, most of which seem to be in line with the role attributed to hTERT regarding its contribution to the acquisition of malignant potential during astrocyte carcinogenesis. Low-grade tumors mainly express Adel and Bdel. High-grade tumors, especially grade IV, always express A+B+, mostly but not always in predominance over Adel and Bdel. In this same group, profiles with Bdel predominance or relatively equal A+B+/Bdel expression are also observed, and Adel is often missing. Whether these differences characterize tumors with different biological behavior remains to be elucidated.

Adolescent↗
PubMed2001

Spatial variability of genomic aberrations in a large glioblastoma resection specimen.

In the present study, the distribution of genetic aberrations in a glioblastoma resection specimen of unusually large size (9x8x2 cm) was investigated using comparative genomic hybridization (CGH). CGH was performed on 20 samples taken from the specimen, and the genetic aberrations found were compared with the regional histology. The samples were histopathologically graded according to WHO criteria, and a division in high- and low-grade areas and infiltration rims was made. In high-grade areas, low-grade areas as well as infiltration rims, gains on 10p11.2-pter (14/20), 11q12-q22 (6/20) and losses on 4q13-qter (9/20), 10q22-qter (8/20), 11p14-pter (5/20), 13q12-qter (7/20) were revealed. Gains on 1q21-32 (2/4) and losses on 7p21-pter (3/4) were exclusively found in the high-grade areas. In the low-grade tumor samples and in the infiltration rim, gains on 16p11.2-pter (6/16), 17p11.2-pter (6/16), 17q11.2-qter (5/16), 20q11.2-q13 (3/16) and deletions on 5q31-qter (4/16) were detected. Gains on 7q21-qter (8/11) and 8q11.2-qter (6/11), and loss of chromosome 9 (4/11) and the Y-chromosome (4/11) were found in the high-grade and low-grade samples, not in the infiltration rims. The finding of a set of identical chromosomal aberrations throughout the resection specimen, most of which have been previously reported in gliomas, confirms a mechanism of clonal tumor proliferation operative in gliomas. The previously unreported genetic alterations which were predominantly traced in the tumor rims, might reflect either selection for properties related to infiltrating behavior, or genomic instability of subclones. The findings illustrate the importance of searching for high-grade genetic aberrations in low-grade tumor samples taken from cases in which sampling error is suspected.

Brain Neoplasms↗
PubMed1999

Variable histological expression of dystrophinopathy in two females.

We report two carriers of Xp21 muscular dystrophy with unusual clinical manifestations and striking variability of dystrophin deficiency within the same muscle biopsy. The first patient was a 60-year-old nun with recent onset of cramps and proximal weakness, mimicking an acquired myopathy. Muscle biopsy disclosed slight alterations in one sample and severe dystrophic changes in another; dystrophin was absent in 7% fibers in the former specimen and in 60% in the second. X inactivation was skewed with 90% cells inactivating the same X chromosome. The second patient was a 17-year-old girl with hyperCKemia, learning disability and a family history of X-linked muscular dystrophy. Muscle biopsy displayed slight fiber size variability and some internal nuclei; dystrophin was absent only in one muscle fiber. A second sample with the same morphological features demonstrated dystrophin deficiency with mosaic distribution. The pattern of X inactivation was normal. These cases emphasize the variability of histopathological changes and dystrophin deficiency in Xp21 muscular dystrophy carriers and the risk of sampling errors in muscle biopsy.

Adolescent↗
PubMed2005

An association study between the transthyretin (TTR) gene and mental retardation.

It is known that in the pathogenesis of mental retardation (MR), both genetic and environmental factors (particularly iodine deficiency) appear to play a critical role. Transthyretin (TTR) transports between 20% and 30% of serum thyroxine in normal individuals and it is the main T(4)-binding protein in CSF. Variability in the TTR gene may influence risk for iodine-deficiency-based MR. The SNPs we selected from dbSNP were detected and identified using ARMS-PCR and sequencing methods, and we identified five novel sequence variants. Singular-locus association analysis indicated no association between the TTR gene and MR. In haplotype analysis, however, we found a haplotype CGTG+ (rs723744/G+6649C/T+6690C/rs2276382/del9) showed a weak positive association with MR (chi(2) = 6.699, p = 0.035). Finally, we concluded that the weak positive result is more likely to be due to sampling error and the small size of this haplotype resulting from its relative low frequency. Our negative results provide no evidence that variants of TTR gene influence susceptibility to MR in the iodine-deficient areas of China and suggest that there may be a compensatory mechanism(s) in humans and mice, which work(s) to compensate the effect of mutation in the TTR gene on MR.

Child↗
PubMed2005

Preferred location for the development of esophageal adenocarcinoma within a segment of intestinal metaplasia.

BACKGROUND: Barrett's metaplasia is the predominant precursor for the development of esophageal adenocarcinoma. This precancerous lesion has become the focus of various surveillance programs aimed at detecting earlier and therefore potentially curable lesions. However, sampling error by missing invasive cancer lesions is a common problem. This study aimed to identify preferred locations within a segment of Barrett's mucosa for the development of esophageal adenocarcinoma. METHODS: The study group consisted of 213 patients with histologically proven esophageal adenocarcinoma. Of those, there were 134 cases of early cancer and 79 cases of locally advanced lesions. These patients received neoadjuvant chemotherapy. The frequency of intestinal metaplasia and the location of the tumor occurrence within the segment of intestinal metaplasia were assessed. RESULTS: Intestinal metaplasia was found in 83% of the early lesions and in 98% of the advanced tumors after neoadjuvant chemotherapy. In 82.2% of the cases, the tumor was located at the distal margin of the intestinal metaplasia in patients with early tumor manifestations. The remaining tumor mass after neoadjuvant therapy also was located predominantly at the distal margin of the segment of intestinal metaplasia (85% of the cases). CONCLUSIONS: The results demonstrate that almost all adenocarcinomas of the esophagus are based on the development of a segment of intestinal metaplasia. The distal margin of Barrett's mucosa seems to be the most vulnerable location for the development of invasive cancer.

Adenocarcinoma↗
PubMed2004

Pancreatic tumors: role of imaging in the diagnosis, staging, and treatment.

Because most patients with pancreatic cancer present with biliary obstruction, percutaneous transhepatic cholangiopancreatography (PTC) or endoscopic retrograde cholangiopancreatography (ERCP) is often performed first to relieve obstruction. Fine needle biopsy (FNA) provides a tissue diagnosis, but is often nondiagnostic due to sampling error. Computed tomography (CT) is the workhorse of oncology, but is poor at defining the nature of pancreatic lesions. Small primary tumors are often not visualized. Fast magnetic resonance imaging (MRI) techniques allowing dynamic imaging after IV gadolinium and new contrast agents allow better characterization of the lesions for patients having contraindications for IV CT contrast agents. Magnetic resonance cholangiopancreatography (MRCP) allows noninvasive visualization of the biliary tree. Endoscopic ultrasonography (EUS) allows evaluation of the detailed regional anatomy with the possibility of FNA. 18F-Fluorodeoxyglucose (FDG) is the most common tracer used in positron emission tomography (PET), and most malignant tumors, including pancreatic carcinoma, have increased FDG uptake compared with normal cells. This functional imaging does not replace but is complementary to morphological imaging. FDG PET is particularly helpful: (1) for the diagnosis in patients with suspected pancreatic cancer in whom CT fails to identify a mass, or those in whom FNAs are nondiagnostic; (2) for staging by detecting CT-occult metastases; (3) for detecting recurrence; and (4) for monitoring therapy. Limitations include false-positive inflammatory processes and false-negative carcinoma in patients with diabetes and hyperglycemia, and islet cell tumors.

Adenocarcinoma↗
PubMed2001

Review of histological classifications of gastrointestinal epithelial neoplasia: differences in diagnosis of early carcinomas between Japanese and Western pathologists.

Gastrointestinal lesions considered to be high-grade adenoma/dysplasia by Western pathologists using the conventional Western classification are often diagnosed as carcinoma by Japanese pathologists using the Japanese group classification. To overcome these differences, the Padova classification, the Vienna classification, and a revision of the Vienna classification have recently been proposed. The clinical usefulness of these five classifications needs to be reviewed for early gastric, esophageal, and colorectal neoplasias. In 1998, 31 pathologists from 12 countries individually diagnosed the same 35 gastric, 21 esophageal, and 20 colorectal specimens. Their histological diagnoses can be classified conventionally and according to the newly proposed terminology, and from these data, the extent of agreement between pathologists with Western and Japanese viewpoints can be calculated, using kappa statistics. With the conventional Western, Japanese, Padova, Vienna, and revised classifications, the agreement scores were 37%, 37%, 71%, 71%, and 80%, respectively, for gastric lesions; 14%, 14%, 57%, 62%, and 67% for esophageal lesions; and 45%, 50%, 65%, 65%, and 70% for colorectal lesions. The kappa values were lower than 0.3 with the conventional Western and Japanese classifications, but higher than 0.5 for gastric lesions, higher than 0.3 for esophageal lesions, and higher than 0.4 for colorectal lesions with the newly proposed classifications. When the literature regarding treatment indications for early neoplastic lesions is reviewed, it becomes apparent that the categories of the revised classification would fit best with current clinical treatment considerations. This classification would be particularly useful for endoscopically resected specimens, to determine whether additional surgery with lymph node dissection is required. In conclusion, the use of the newly proposed terminology can, in large part, resolve the intercountry differences in the diagnosis of adenoma/dysplasia and early carcinoma. However, the newly proposed classifications should be used with caution for biopsy specimens, as sampling error may result in an underestimation of the neoplastic grade or depth of invasion. For the choice between endoscopic and surgical treatment, assessment of the depth of invasion by endoscopic inspection and ultrasound or radiography is essential.

Adenoma↗
PubMed2002

Sentinel lymph node biopsy as a tool for the staging of ductal carcinoma in situ in patients with breast carcinoma.

PURPOSE: Ductal carcinoma in situ (DCIS) of the breast is defined as stage 0 disease, but its diagnosis is subject to sampling errors. This study was conducted to assess the usefulness of sentinel lymph node biopsy (SLNB) for furnishing indirect evidence of the invasion of tumors diagnosed as DCIS. METHODS: A total of 201 SLNB procedures performed using a peritumoral tracer, being either dye alone or dye plus 99mTc-labeled colloidal albumin, were reviewed. The cases of DCIS were selected for analysis, and the results were compared with published data. RESULTS: Among ten cases of DCIS studied by SLNB, only one had micrometastatic nodal involvement, which was revealed by cytokeratin immunostaining, and was limited to the sentinel node. This was a large intermediate-grade micropapillary/cribriform-type DCIS. CONCLUSION: These findings indicate that while SLNB may be a valuable tool for the staging of tumors diagnosed as DCIS, it should not be performed in all cases, but probably restricted to large, high-grade, or comedo-type intraductal carcinomas.

Axilla↗