Quantitative image analysis in the assessment of diffuse large B-cell lymphoma.

Proliferation rates in diffuse large B-cell lymphoma have been associated with conflicting outcomes in the literature, more often with high proliferation associated with poor prognosis. In most studies, the proliferation rate was estimated by a pathologist using an immunohistochemical stain for the monoclonal antibody Ki-67. We hypothesized that a quantitative image analysis algorithm would give a more accurate estimate of the proliferation rate, leading to better associations with survival. In all, 84 cases of diffuse large B-cell lymphoma were selected according to the World Health Organization criteria. Ki-67 percentage positivity estimated by the pathologist was recorded from the original report. The same slides were then scanned using an Aperio ImageScope, and Ki-67 percentage positivity was calculated using a computer-based quantitative immunohistochemistry nuclear algorithm. In addition, chart review was performed and survival time was recorded. The Ki-67 percentage estimated by the pathologist from the original report versus quantitative image analysis was significantly correlated (P<0.001), but pathologist Ki-67 percentages were significantly higher than quantitative image analysis (P=0.021). There was less agreement at lower Ki-67 percentages. Comparison of Ki-67 percentage positivity versus survival did not show significant association either with pathologist estimate or quantitative image analysis. However, although not significant, there was a trend of worse survival at higher proliferation rates detected by the pathologist but not by quantitative image analysis. Interestingly, our data suggest that the Ki-67 percentage positivity as assessed by the pathologist may be more closely associated with survival outcome than that identified by quantitative image analysis. This may indicate that pathologists are better at selecting appropriate areas of the slide. More cases are needed to assess whether this finding would be statistically significant. Due to the good correlation between pathologist estimate and quantitative image analysis, there is no substantial benefit to using quantitative image analysis at this point of time.

Teaching Genomic Pathology: Translating Team-Based Learning to a Virtual Environment Using Computer-Based Simulation.

CONTEXT.­: Developing skills related to use of computer-based tools is critical for practicing genomic pathology. However, given the relative novelty of genomics education, residency programs may lack faculty members with adequate expertise and/or time to implement training. A virtual team-based learning (TBL) environment would make genomic pathology education available to more trainees. OBJECTIVE.­: To translate an extensively implemented in-person TBL genomic pathology workshop into a virtual environment and to evaluate both knowledge and skill acquisition. DESIGN.­: Using a novel interactive simulation approach, online modules were developed translating aspects of the TBL experience into the virtual environment with a goal of acquisition of necessary computer-related skills. The modules were evaluated at 10 postgraduate pathology training programs using a pre-post test design with participants deidentified. A postmodule anonymous survey obtained participant feedback on module quality and efficacy. RESULTS.­: There were 147 trainees who received an email request to voluntarily participate in the study. Of these, 43 trainees completed the pretest and 15 (35%) subsequently completed the posttest. Mean overall scores were 45% on the pretest compared with 70% on the posttest ( P < .001; effect size = 1.4). Posttest improvement of results was similar for questions testing acquisition of knowledge versus skills. Regarding the 19 participants who took the survey, 18 (95%) would recommend the modules to others and believed they met the stated objectives. CONCLUSIONS.­: A simulation-based approach allows motivated pathology trainees to acquire computer-related skills for practicing genomic pathology. Future work can explore efficacy in a nonvoluntary setting and adaptation to different specialties, learners, and computer tools.

White blood cell counts: reference methodology.

Modern hematology laboratories use automated hematology analyzers to perform cell counts. These instruments provide accurate, precise, low-cost differential counts with fast turnaround times. Technologies commonly used include electrical impedance, radiofrequency conductivity, laser light scattering, and cytochemistry. This article reviews the principles of these methodologies and possible sources of error, provides guidance for selecting flagging criteria, and discusses novel, clinically relevant white blood cell parameters provided by new instruments, including immature granulocyte count and granularity index.

Comparative Analysis Reveals Potential Utility of Digital Microscopy in the Evaluation of Peripheral Blood Smears With Some Barriers to Implementation.

OBJECTIVES: Evaluation of the peripheral blood smear (PBS) is an essential diagnostic test in current medical practice. We aimed to evaluate the use of digital microscopy for the examination of PBS as an option to provide expert interpretation to remote sites and in "on-call" situations. METHODS: We collected 100 Wright-Giemsa-stained PBS slides representing normal and abnormal findings seen at a community-based hospital. Four hematopathologists independently evaluated the cases using conventional light and digital microscopy. RESULTS: When comparing digital vs light microscopy, most of the cellular features evaluated showed at least a moderate degree of agreement in at least three of the reviewers. Discrepancies in final diagnosis were identified in a minority of the cases, most of which were attributed to the poorer resolution of digital microscopy at high magnification (×400). CONCLUSIONS: These results support the limited use of digital microscopy for evaluation and triage of peripheral blood smears as a practical option to obtain expert opinion in locations where experienced staff is not available on site. Our results indicate that while digital microscopy is well suited for basic triage of these blood smears, limitations in quality of imaging at higher magnification as well as large file size may limit its utility in certain settings and situations.