Molecular pathology is becoming more and more important in present day pathology. A major challenge for any molecular test is its ability to reliably detect mutations in samples consisting of ...mixtures of tumor cells and normal cells, especially when the tumor content is low. The minimum percentage of tumor cells required to detect genetic abnormalities is a major variable. Information on tumor cell percentage is essential for a correct interpretation of the result. In daily practice, the percentage of tumor cells is estimated by pathologists on hematoxylin and eosin (H&E)-stained slides, the reliability of which has been questioned. This study aimed to determine the reliability of estimated tumor cell percentages in tissue samples by pathologists. On 47 H&E-stained slides of lung tumors a tumor area was marked. The percentage of tumor cells within this area was estimated independently by nine pathologists, using categories of 0–5%, 6–10%, 11–20%, 21–30%, and so on, until 91–100%. As gold standard, the percentage of tumor cells was counted manually. On average, the range between the lowest and the highest estimate per sample was 6.3 categories. In 33% of estimates, the deviation from the gold standard was at least three categories. The mean absolute deviation was 2.0 categories (range between observers 1.5–3.1 categories). There was a significant difference between the observers (P<0.001). If 20% of tumor cells were considered the lower limit to detect a mutation, samples with an insufficient tumor cell percentage (<20%) would have been estimated to contain enough tumor cells in 27/72 (38%) observations, possibly causing false negative results. In conclusion, estimates of tumor cell percentages on H&E-stained slides are not accurate, which could result in misinterpretation of test results. Reliability could possibly be improved by using a training set with feedback.
Identification of patients at risk for primary and secondary manifestations of atherosclerotic disease progression is based mainly on established risk factors. The atherosclerotic plaque composition ...is thought to be an important determinant of acute cardiovascular events, but no prospective studies have been performed. The objective of the present study was to investigate whether atherosclerotic plaque composition is associated with the occurrence of future vascular events.
Atherosclerotic carotid lesions were collected from patients who underwent carotid endarterectomy and were subjected to histological examination. Patients underwent clinical follow-up yearly, up to 3 years after carotid endarterectomy. The primary outcome was defined as the composite of a vascular event (vascular death, nonfatal stroke, nonfatal myocardial infarction) and vascular intervention. The cumulative event rate at 1-, 2-, and 3-year follow-up was expressed by Kaplan-Meier estimates, and Cox proportional hazards regression analyses were performed to assess the independence of histological characteristics from general cardiovascular risk factors. During a mean follow-up of 2.3 years, 196 of 818 patients (24%) reached the primary outcome. Patients whose excised carotid plaque revealed plaque hemorrhage or marked intraplaque vessel formation demonstrated an increased risk of primary outcome (risk difference=30.6% versus 17.2%; hazard ratio HR with 95% confidence interval=1.7 1.2 to 2.5; and risk difference=30.0% versus 23.8%; HR=1.4 1.1 to 1.9, respectively). Macrophage infiltration (HR=1.1 0.8 to 1.5), large lipid core (HR=1.1 0.7 to 1.6), calcifications (HR=1.1 0.8 to 1.5), collagen (HR=0.9 0.7 to 1.3), and smooth muscle cell infiltration (HR=1.3 0.9 to 1.8) were not associated with clinical outcome. Local plaque hemorrhage and increased intraplaque vessel formation were independently related to clinical outcome and were independent of clinical risk factors and medication use.
The local atherosclerotic plaque composition in patients undergoing carotid endarterectomy is an independent predictor of future cardiovascular events.
Cryoablation can be used for the treatment of Barrett's esophagus (BE). A recent dosimetry study, using the CryoBalloon Focal Ablation System (CryoBalloon), demonstrated that 10-second ablations ...result in complete eradication of BE. However, the efficacy of 10-second ablation in a larger cohort of patients has not been investigated, nor has the potential of precise targeting of specific areas. The aim of the study was to assess the efficacy and performance (i. e. targeting of BE islands) of a 10-second cryoablation using the CryoBalloon.
A total of 30 patients were enrolled (worst pathology: low grade dysplasia in 14 47 %, high grade dysplasia in 7 23 %, early adenocarcinoma in 9 30 %). Of the 47 BE islands, 44 (94 %) were adequately targeted. Complete eradication of intestinal metaplasia and dysplasia was observed in 100 % of the completely ablated areas. No stenoses were observed.
Cryoablation of BE islands using the CryoBalloon is effective. BE islands were effectively targeted.
Differentiation between multiple primary lung cancers and pulmonary metastases (PM) has important implications in staging, prognosis, and treatment strategies. Clinical and immunohistopathologic ...criteria have been standardized; however, a substantial number of cases remain difficult to classify. Using next-generation sequencing, it is now possible to improve the classification of multiple lung cancer lesions. This study systematically investigated the value of routine morphologic and IHC characteristics, p53 protein expression, TP53 mutation analysis, and 50-gene panel sequencing (GPS) in 111 lesions from 50 patients with multiple lung lesions. Based on immunohistopathologic criteria, 32 paired lesions were classified as multiple primary lung cancer (MPLC) and 21 as PM. TP53 mutation analysis indicated MPLC in 23 and PM in 6 pairs, but in the majority of cases (n = 28, 49%) no mutation was observed and no conclusion could be drawn. In contrast, only 2 pairs were not conclusive using GPS. In a significant number of matching tumor samples (n = 19, 39%), sequencing results were contradictory to the initial immunohistopathology diagnosis. No separation in overall survival for classifications based on immunohistopathology was observed, while a clear but nonsignificant trend was observed concerning survival in MPLC patients (hazard ratio = 3.98) using 50-gene GPS. In about one-third of the patients, GPS provided additional information to improve the differentiation between MPLC and PM.
Background Carotid endarterectomy to prevent a stroke is less beneficial for women compared with men. This benefit is lower in asymptomatic women compared with asymptomatic men or symptomatic ...patients. A possible explanation for this gender-associated difference in outcome could be found in the atherosclerotic carotid plaque phenotype. We hypothesize that women, especially asymptomatic women, have more stable plaques than men, resulting in a decreased benefit of surgical plaque removal. Methods Carotid endarterectomy specimens of 450 consecutive patients (135 women, 315 men) were studied. The culprit lesions were semi-quantitatively analyzed for the presence of macrophages, smooth muscle cells, collagen, calcifications, and luminal thrombus. Plaques were categorized in three phenotypes according to overall presentation and the amount of fat. Protein was isolated from the plaques for determination of interleukin-6 (IL-6) and IL-8 concentrations and matrix metalloproteinase-8 (MMP-8) and MMP-9 activities. Results Atheromatous plaques (>40% fat) were less frequently observed in women than in men (22% vs 40%; P < .001). In addition, plaques obtained from women more frequently revealed low macrophage staining (11% vs 18%; P = .05) and strong smooth muscle cell staining (38% vs 24%; P = .001). Compared with men, women had a lower plaque concentration of IL-8 ( P = .001) and lower MMP-8 activity ( P = .01). The observed differences were most pronounced in asymptomatic women, who showed the most stable plaques, with an atheromatous plaque in only 9% of cases compared with 39% in asymptomatic men ( P = .02). In addition, a large proportion of plaques obtained from asymptomatic women showed high smooth muscle cell content (53% vs 30%; P = .03) and high collagen content (55% vs 24%; P = .003). All relations between gender and plaque characteristics, except for MMP-8, remained intact in a multivariate analysis, including clinical presentation and other cardiovascular risk factors. Conclusion Carotid artery plaques obtained from women have a more stable, less inflammatory phenotype compared with men, independent of clinical presentation and cardiovascular risk profile. Asymptomatic women demonstrate the highest prevalence of stable plaques. These findings could explain why women benefit less from carotid endarterectomy compared with men.
Endoscopic cryoablation for Barrett's esophagus (BE) might offer advantages over heat-based ablation. Focal cryoballoon ablation has been promising for short-segment BE, whereas the novel 90°-swipe ...cryoballoon ablation system (CbSAS
) ablates larger areas in a single step (90° over 3 cm). The system allows for dose adjustment. CbSAS
has been feasible and safe in animal and pre-esophagectomy studies. This is the first clinical study to assess feasibility, safety, and efficacy of CbSAS
for eradication of dysplastic BE.
In this prospective study in dysplastic BE patients, dose finding started with semi-circumferential treatment at 0.8 mm/s (dose 1). The dose was escalated by reducing speed by 0.1 mm/s in six patients until BE surface regression was ≥ 80 % without complications ("effective dose"). The effective dose was subsequently confirmed with circumferential treatment in 12 new patients. Post-procedural pain (0 - 10) and dysphagia (0 - 4) were evaluated. Outcomes were feasibility, safety, and BE surface regression.
25 patients were included, with technically successful treatment in 92 % (95 %CI 73 % - 99 %). Median (95 %CI) BE surface regression was 78 % (50 % - 85 %) for dose 1 and 85 % (55 % - 95 %) for dose 2 (0.7 mm/s), which was defined as the effective dose. Circumferential treatment resulted in 93 % (88 % - 96 %) regression. Two of 12 patients with circumferential treatment developed strictures that required dilation. Median pain and dysphagia scores were low (0 - 3 and 0, respectively).
CbSAS
was feasible and effective for ablating larger BE areas. The optimal dose for circumferential treatment that balances safety and efficacy requires further evaluation.
Brachyspira species are fastidious anaerobic microorganisms, that infect the colon of various animals. The genus contains both important pathogens of livestock as well as commensals. Two species are ...known to infect humans: B. aalborgi and B. pilosicoli. There is some evidence suggesting that the veterinary pathogenic B. pilosicoli is a potential zoonotic agent, however, since diagnosis in humans is based on histopathology of colon biopsies, species identification is not routinely performed in human materials.
The study population comprised 57 patients with microscopic evidence of Brachyspira infection and 26 patients with no histopathological evidence of Brachyspira infection. Concomitant faecal samples were available from three infected patients. Based on publically available 16S rDNA gene sequences of all Brachyspira species, species-specific primer sets were designed. DNA was extracted and tested by real-time PCR and 16S rDNA was sequenced.
Sensitivity and specificity for identification of Brachyspira species in colon biopsies was 100% and 87.7% respectively. Sequencing revealed B. pilosicoli in 15.4% of patients, B. aalborgi in 76.9% and a third species, tentatively named "Brachyspira hominis", in 26.2%. Ten patients (12.3%) had a double and two (3.1%) a triple infection. The presence of Brachyspira pilosicoli was significantly associated with inflammatory changes in the colon-biopsy (p=0.028).
This newly designed PCR allows for sub-differentiation of Brachyspira species in patient material and thus allows large-scaled surveillance studies to elucidate the pathogenicity of human Brachyspira infections. One-third of affected patients appeared to be infected with a novel species.
Endoscopic resection is the cornerstone of treatment of Barrett’s esophagus (BE)-related neoplasia. However, accurate histopathologic evaluation of endoscopic resection specimens can be challenging, ...and the preferred specimen handling method remains unknown. Therefore, the aim of our study was to compare 3 different specimen handling methods for assessment of all clinically relevant histopathologic parameters and time required for specimen handling.
In this multicenter, randomized study EMR specimens of BE-related neoplasia with no suspicion of submucosal invasion during endoscopy were randomized to 3 specimen handling methods: pinning on paraffin using needles, direct fixation in formalin without prior tissue handling, and the cassette technique (small box for enclosing specimens). The histopathologic evaluation scores were assessed by 2 dedicated GI pathologists blinded to the handling method.
Of the 126 randomized EMR specimens, 45 were assigned to pinning on paraffin, 41 to direct fixation in formalin, and 40 to the cassette technique. The percentages of specimens with overall optimal histopathologic evaluation scores were similar for the pinning method (98%; 95% confidence interval CI, 88.0-99.9) and for no handling (90%; 95% CI, 76.9-97.3) but were significantly lower (64%; 95% CI, 47.2-78.8) for the cassette technique (P < .001). Time required for specimen handling was shortest when no handling method was used (P < .001 vs pinning and cassette).
Both pinning on paraffin and direct fixation in formalin resulted in optimal histopathologic evaluation scores in a high proportion of specimens, whereas the cassette technique performs significantly worse, and its use in clinical daily practice should be discouraged. Given the significantly shorter handling time, direct fixation in formalin appears to be the preferred method over pinning on paraffin. However, the latter needs to be confirmed in larger studies with inclusion of all EMR specimens. (Clinical trial registration number: ISRCTN50525266.)
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