In digital pathology, tissue slides are scanned into Whole Slide Images (WSI) and pathologists first screen for diagnostically-relevant Regions of Interest (ROIs) before reviewing them. Screening for ...ROIs is a tedious and time-consuming visual recognition task which can be exhausting. The cognitive workload could be reduced by developing a visual aid to narrow down the visual search area by highlighting (or segmenting) regions of diagnostic relevance, enabling pathologists to spend more time diagnosing relevant ROIs. In this paper, we propose HistoSegNet, a method for semantic segmentation of histological tissue type (HTT). Using the HTT-annotated Atlas of Digital Pathology (ADP) database, we train a Convolutional Neural Network on the patch annotations, infer Gradient-Weighted Class Activation Maps, average overlapping predictions, and post-process the segmentation with a fully-connected Conditional Random Field. Our method out-performs more complicated weakly-supervised semantic segmentation methods and can generalize to other datasets without retraining.
This study evaluates compositions of tantalum-containing mesoporous bioactive glass (Ta-MBG) powders using a porcine fatal liver injury model. The powders based on (80-
x
)SiO
2
-15CaO-5P
2
O
5
-
x
...Ta
2
O
5
compositions with
x
= 0 (0Ta/Ta-free), 1 (1Ta), and 5 (5Ta) mol% were made using a sol–gel process. A class IV hemorrhage condition was simulated on the animals; hemodynamic data and biochemical analysis confirmed the life-threatening condition. Ta-MBGs were able to stop the bleeding within 10 min of their application while the bleeds in the absence of any intervention or in the presence of a commercial agent, Arista
TM
(Bard Davol Inc., Rhode Island, USA) continued for up to 45 min. Scanning electron microscopy (SEM) imaging of the blood clots showed that the presence of Ta-MBGs did not affect clot morphology. Rather, the connections seen between fibrin fibers of the blood clot and Ta-MBG powders point towards the powders’ surfaces embracing fibrin. Histopathological analysis of the liver tissue showed 5Ta as the only composition reducing parenchymal hemorrhage and necrosis extent of the tissue after their application. Additionally, 5Ta was also able to form an adherent clot in worst-case scenario bleeding where no adherent clot was seen before the powder was applied. In vivo results from the present study agree with in vitro results of the previous study that 5Ta was the best Ta-MBG composition for hemostatic purposes.
Graphical abstract
Summary The aim of this study was to ascertain the level of concordance among gastrointestinal pathologists for regression grading in rectal cancers treated with neoadjuvant chemoradiation. Seventeen ...gastrointestinal pathologists participated using the Mandard, Dworak, and modified rectal cancer regression grading systems to grade 10 representative slides that were selected from 10 cases of rectal cancer treated with long-course neoadjuvant chemoradiation. The slides were scanned with a whole-slide scanner generating dynamic digitized images. The results showed very little concordance across the 3 grading systems, with κ values of 0.28, 0.35, and 0.38 for the Mandard, Dworak, and modified rectal cancer regression grading systems, respectively. In only 1 of 10 study cases was there unanimous grading concordance using the modified rectal cancer regression grading system. It was felt that these systems lacked precision and clarity for reproducible, accurate regression grading. The study concluded that there was a need for a simple, reproducible regression grading system with clear criteria, a cumulative or composite score taking into account all sections of the tumor bed that is sampled rather than the worst section (highest grade), and there should be a uniform method of sampling of these specimens.
The resection margin status is a significant surgical prognostic factor for the long-term outcomes of patients undergoing pancreaticoduodenectomy (Whipple procedure). As a result, surgeons frequently ...rely on intraoperative consults (IOCs) involving frozen sections to evaluate margin clearance during these resections. Nevertheless, the impact of this practice on final margin status and long-term outcomes remains a topic of debate. This study aimed to assess the impact of IOCs on the clearance rate of resection margins following Whipple procedure and distal pancreatectomy. A retrospective database review of all patients who underwent Whipple procedure or distal pancreatectomy at our institution between 2018 and 2020 was performed to evaluate the utility of IOCs by gastrointestinal surgeons and its correlation with final postoperative surgical margin status. A significant variation in the frequency of IOC requests for margins among surgeons was noted. However, the use of frozen section analysis for intraoperative margin assessment was not significantly associated with the clearance rate of final post-operative margins. More frequent use of IOC did not result in higher final margin clearance rate, an important prognostic factor following Whipple procedure.
ObjectivesWe aim to determine what threshold of compressive stress small bowel and colon tissues display evidence of significant tissue trauma during laparoscopic surgery.DesignThis study included 10 ...small bowel and 10 colon samples from patients undergoing routine gastrointestinal surgery. Each sample was compressed with pressures ranging from 100 kPa to 600 kPa. Two pathologists who were blinded to all study conditions, performed a histological analysis of the tissues. Experimentation: November 2018–February 2019. Analysis: March 2019–May 2020.SettingAn inner-city trauma and ambulatory hospital with a 40-bed inpatient general surgery unit with a diverse patient population.ParticipantsPatients were eligible if their surgery procured healthy tissue margins for experimentation (a convenience sample). 26 patient samples were procured; 6 samples were unusable. 10 colon and 10 small bowel samples were tested for a total of 120 experimental cases. No patients withdrew their consent.InterventionsA novel device was created to induce compressive “grasps” to simulate those of a laparoscopic grasper. Experimentation was performed ex-vivo, in-vitro. Grasp conditions of 0–600 kPa for a duration of 10 s were used.ResultsSmall bowel (10), M:F was 7:3, average age was 54.3 years. Colon (10), M:F was 1:1, average age was 65.2 years. All 20 patients experienced a significant difference (p<0.05) in serosal thickness post-compression at both 500 and 600 kPa for both tissue types. A logistic regression analysis with a sensitivity of 100% and a specificity of 84.6% on a test set of data predicts a safety threshold of 329–330 kPa.ConclusionsA threshold was discovered that corresponded to both significant serosal thickness change and a positive histological trauma score rating. This “force limit” could be used in novel sensorized laparoscopic tools to avoid intraoperative tissue injury.
Schizophyllum commune (S. commune)
is an environmental basidiomycete bracket fungus that can rarely cause invasive fungal disease. Its diagnosis is challenging and often missed. We present a rare ...case of a 56-year-old diabetic gentleman with a 6-months history of progressive productive cough, small volume hemoptysis and non-resolving fungal empyema treated with video-assisted thoracoscopic decortication. Pulmonary infection of
S. Commune
is extremely rare and can manifest as complex fungal empyema. Close cooperation between respirologists, thoracic surgeons and microbiologists is critical in the diagnosis and treatment of such cases.
To apply magnetic resonance (MR) imaging of intraplaque hemorrhage (IPH), as compared with histologic analysis as the reference standard, to detect T1 hyperintense intraplaque signal and to test the ...hypothesis that T1 hyperintense material represents blood products (methemoglobin).
Institutional review board approval and patient informed consent were obtained. Eleven patients undergoing carotid endarterectomy were examined with MR imaging of IPH, and MR images were assessed for T1 hyperintense intraplaque signal. A total of 160 images per patient were available for coregistration with corresponding histologic slices. Because of endarterectomy specimen size and degradation and processing artifacts, only 97 images were coregistered to corresponding histologic slices. A grid that consisted of 16 segments was overlaid on images for correlation of MR images and histologic slices. Only one of 16 segments was chosen randomly per slide and used in the analysis. Agreement between MR images and histologic slices was measured with the Cohen kappa statistic.
Strong agreement was seen between MR images and histologic slices, with T1-weighted high signal intensity corresponding to hemorrhagic material (kappa = 0.7-0.8). There was a low 2% false-negative rate for the detection of hemorrhage on the basis of T1-weighted hyperintensity (two of 97 measured segments). The results of diagnostic tests for T1 hyperintense detection of hemorrhage were as follows: sensitivity of 100%, specificity of 80%, positive predictive value of 70%, and negative predictive value of 100% for reader 1 and sensitivity of 94%, specificity of 88%, positive predictive value of 78%, and negative predictive value of 97% for reader 2.
With its high spatial resolution, MR imaging of IPH permits detection of plaque hemorrhage location, resulting in strong agreement between imaging and histologic findings.
Abstract Gangliocytic paragangliomas are a rare but well-described neuroendocrine tumor with a proclivity for the duodenal area. It is usually a locally infiltrative lesion with a good prognosis. ...Rare cases that spread to lymph nodes have been documented. A 52-year-old female was found to have a duodenal tumor, enlarged regional lymph nodes, and multiple small nodules in the liver. The duodenal tumor was a classic triphasic gangliocytic paraganglioma. Two regional lymph nodes and one of the nodules in the liver were noted to contain all 3 elements constituting a gangliocytic paraganglioma. This is the second case of gangliocytic paraganglioma with liver spread and is also noteworthy because of the presence of all 3 elements in the metastases. The presence of lymph node and liver metastases should not result in overtreatment as such behavior is not necessarily fraught with a bad clinical outcome. It is probably best to regard such cases as having “uncertain malignant potential” and advocate careful follow-up.
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