The 1000 Mitoses Project: A Consensus-Based International Collaborative Study on Mitotic Figures Classification.

Introduction. The identification of mitotic figures is essential for the diagnosis, grading, and classification of various different tumors. Despite its importance, there is a paucity of literature reporting the consistency in interpreting mitotic figures among pathologists. This study leverages publicly accessible datasets and social media to recruit an international group of pathologists to score an image database of more than 1000 mitotic figures collectively. Materials and Methods. Pathologists were instructed to randomly select a digital slide from The Cancer Genome Atlas (TCGA) datasets and annotate 10-20 mitotic figures within a 2 mm2 area. The first 1010 submitted mitotic figures were used to create an image dataset, with each figure transformed into an individual tile at 40x magnification. The dataset was redistributed to all pathologists to review and determine whether each tile constituted a mitotic figure. Results. Overall pathologists had a median agreement rate of 80.2% (range 42.0%-95.7%). Individual mitotic figure tiles had a median agreement rate of 87.1% and a fair inter-rater agreement across all tiles (kappa = 0.284). Mitotic figures in prometaphase had lower percentage agreement rates compared to other phases of mitosis. Conclusion. This dataset stands as the largest international consensus study for mitotic figures to date and can be utilized as a training set for future studies. The agreement range reflects a spectrum of criteria that pathologists use to decide what constitutes a mitotic figure, which may have potential implications in tumor diagnostics and clinical management.

Impact of HER2-Low status in metastatic gastric cancer:A real-world retrospective cohort study.

INTRODUCTION: Information regarding HER2-low tumors in metastatic gastric cancer is sparse. Our aim here was to determine the frequency of low HER2 expression in metastatic gastric cancer and to compare the clinicopathological characteristics, survival, and treatment response of HER2-low patients with HER2-zero patients. METHODS: All the data were collected retrospectively from computerized system of the hospital. We categorized the patients according to clinicopathological features, treatment responses, and survival in terms of HER2-low tumors and HER2-zero tumors. RESULTS: Of 226 patients, 71 (31.4%) had low HER2 expression and 155 (68.6%) had zero HER2 expression. HER2-low tumors were detected more frequently in older patients and in low-grade tumors than HER2-zero tumors (69% vs 47.7%, P = 0.003, 16.9% vs 3.8%, P < 0.001). All patients received a first-line chemotherapy regimen. The disease control rate was not statistically different between both groups (40% vs 46.4%, P=0.11). The median survival was 12.05 (95% CI, 8.09-16.02) months in HER2-low patients, and 10.41 (95% CI, 8.52-12.3) months in HER20-zero patients with no statistical difference (P=0.73). CONCLUSION: HER2-low metastatic gastric cancer has a higher rate of being low-grade than HER2-zero tumors. HER2-low metastatic gastric cancer is similar to HER2-zero in terms of chemotherapy response and survival.

Assessment of Pathology Domain-Specific Knowledge of ChatGPT and Comparison to Human Performance.

CONTEXT.­: Artificial intelligence algorithms hold the potential to fundamentally change many aspects of society. Application of these tools, including the publicly available ChatGPT, has demonstrated impressive domain-specific knowledge in many areas, including medicine. OBJECTIVES.­: To understand the level of pathology domain-specific knowledge for ChatGPT using different underlying large language models, GPT-3.5 and the updated GPT-4. DESIGN.­: An international group of pathologists (n = 15) was recruited to generate pathology-specific questions at a similar level to those that could be seen on licensing (board) examinations. The questions (n = 15) were answered by GPT-3.5, GPT-4, and a staff pathologist that recently passed their Canadian pathology licensing exams. Participants were instructed to score answers on a 5-point scale and to predict which answer was written by ChatGPT. RESULTS.­: GPT-3.5 performed at a similar level to the staff pathologist, while GPT-4 outperformed both. The overall score for both GPT-3.5 and GPT-4 was within the range of meeting expectations for a trainee writing licensing examinations. In all but one question, the reviewers were able to correctly identify the answers generated by GPT-3.5. CONCLUSIONS.­: By demonstrating the ability of ChatGPT to answer pathology-specific questions at a level similar to (GPT-3.5) or exceeding (GPT-4) a trained pathologist, this study highlights the potential of large language models to be transformative in this space. In the future, more advanced iterations of these algorithms with increased domain-specific knowledge may have the potential to assist pathologists and enhance pathology resident training.

Rectal biopsy: is it really necessary in anorectal malformations?

AIM OF THE STUDY: The coexistence of Hirschsprung's disease (HD) with anorectal malformation (ARM) is rare but many surgeons still ask pathologists to look for ganglia in the terminal rectum or fistula. In this study, we aimed to highlight the rarity of this association and question the necessity of histological evaluation. METHODS: After obtaining board review approval, rectal specimens of ARM patients who underwent corrective surgery in the last 8 years were re-analyzed by two blinded pathologists for the presence and structure of ganglia. Clinical and radiological data of patients retrieved from center records and correlated with histopathologic findings. MAIN RESULTS: 67 patients with ARM were identified, distal rectal specimen was obtained in 47. The median age at the time of surgery was 11 months (2 days-59 months). A normal pattern of ganglia was present in 51.1% (24/47), 29.7% (14/47) had aganglionosis and 19.1% (9/47) were inconclusive due to insufficient material. None of the aganglionic specimens showed other histological findings of HD. Patients were followed up regularly in the outpatient colorectal clinic for a median of 87 months (42-117 m). Only 6 experienced severe constipation (3 ganglionic, 2 no biopsy, 1 aganglionic), all of whom responded to a bowel management program, and none developed other manifestations of HD (abdominal distension, failure to thrive or enterocolitis) or required additional surgery. CONCLUSIONS: Our results strongly suggest that the association of ARM and HD is extremely rare and the practice of searching for ganglia in the distal rectum or fistula of ARM patients should be discouraged to avoid potential misdiagnosis and overtreatment.

Role of magnetic resonance imaging in the differentiation of mucinous ovarian carcinoma and mucinous borderline ovarian tumors.

OBJECTIVE: This study was carried out to investigate the differentiation of mucinous borderline ovarian tumor from mucinous ovarian carcinoma using magnetic resonance imaging. METHODS: We evaluated 77 women patients who underwent abdominal magnetic resonance imaging due to pelvic mass. magnetic resonance imaging was reviewed by an experienced radiologist. A total of 70 women patients were included in the study. The magnetic resonance imaging features were retrospectively evaluated and compared between the two pathologies. RESULTS: There was no difference between the two groups in terms of maximum tumor size. Age at diagnosis was 56.29±11.92 in the mucinous ovarian carcinoma group and 44.74±13.60 in the mucinous borderline ovarian tumor group (p<0.05). A significant difference was found between the two groups, and it was observed that mucinous borderline ovarian tumors appeared in the younger age group compared to mucinous ovarian carcinomas. Presence of ascites, peritoneal dissemination, lymphadenopathy, and mural nodules was found significantly more frequently in mucinous ovarian carcinomas than in mucinous borderline ovarian tumors. Honeycomb appearance was found more frequently in mucinous borderline ovarian tumor patients than in mucinous ovarian carcinoma patients. CONCLUSION: magnetic resonance imaging findings of these two pathologies overlapped considerably. Compared with mucinous borderline ovarian tumors, mucinous ovarian carcinomas frequently had mural nodules larger than 5 mm, larger tumor size, peritoneal dissemination, and abnormal ascites.

Role of magnetic resonance imaging in the differentiation of mucinous ovarian carcinoma and mucinous borderline ovarian tumors

SUMMARY OBJECTIVE: This study was carried out to investigate the differentiation of mucinous borderline ovarian tumor from mucinous ovarian carcinoma using magnetic resonance imaging. METHODS: We evaluated 77 women patients who underwent abdominal magnetic resonance imaging due to pelvic mass. magnetic resonance imaging was reviewed by an experienced radiologist. A total of 70 women patients were included in the study. The magnetic resonance imaging features were retrospectively evaluated and compared between the two pathologies. RESULTS: There was no difference between the two groups in terms of maximum tumor size. Age at diagnosis was 56.29±11.92 in the mucinous ovarian carcinoma group and 44.74±13.60 in the mucinous borderline ovarian tumor group (p<0.05). A significant difference was found between the two groups, and it was observed that mucinous borderline ovarian tumors appeared in the younger age group compared to mucinous ovarian carcinomas. Presence of ascites, peritoneal dissemination, lymphadenopathy, and mural nodules was found significantly more frequently in mucinous ovarian carcinomas than in mucinous borderline ovarian tumors. Honeycomb appearance was found more frequently in mucinous borderline ovarian tumor patients than in mucinous ovarian carcinoma patients. CONCLUSION: magnetic resonance imaging findings of these two pathologies overlapped considerably. Compared with mucinous borderline ovarian tumors, mucinous ovarian carcinomas frequently had mural nodules larger than 5 mm, larger tumor size, peritoneal dissemination, and abnormal ascites.