Although small cell carcinoma of the gastrointestinal (GI) tract is well-recognized, nonsmall cell type high-grade neuroendocrine carcinoma (HGNEC) of this site remains undefined. At the current time, neither the World Health Organization nor American Joint Committee on Cancer includes this condition in the histologic classifications, and consequently it is being diagnosed and treated inconsistently. In this study, we aimed at delineating the histologic and immunophenotypical spectrum of HGNECs of the GI tract with emphasis on histologic subtypes. Guided primarily by the World Health Organization/International Association for the Study of Lung Cancer criteria for pulmonary neuroendocrine tumors, we were able to classify 87 high-grade GI tract tumors that initially carried a diagnosis of either poorly differentiated carcinoma with or without any neuroendocrine characteristics, small cell carcinoma, or combined adenocarcinoma—neuroendocrine carcinoma into the following 4 categories. The first was small cell carcinoma (n=23), which had features typical of pulmonary small cell carcinoma, although the cells tended to have a more round nuclear contour. The second was large cell neuroendocrine carcinoma (n=31), which had a morphology similar to its pulmonary counterpart and showed positive immunoreactivity for either chromogranin (71%) or synaptophysin (94%) or both. The third was mixed neuroendocrine carcinoma (n=11), which had intermediate histologic features (eg, cells with an increased nuclear/cytoplasmic ratio but with apparent nucleoli), and positive immunoreactivity for at least 1 neuroendocrine marker. The fourth was poorly differentiated adenocarcinoma (n=17). In addition, 5 of the 87 tumors showed either nonsmall cell type neuroendocrine morphology (n=3) or immunohistochemical reactivity for neuroendocrine markers (n=2), but not both. Further analysis showed that most HGNECs arising in the squamous lined parts (esophagus and anal canal) were small cell type (78%), whereas most involving the glandular mucosa were large cell (53%) or mixed (82%) type; associated adenocarcinomas were more frequent in large cell (61%) or mixed (36%) type than in small cell type (26%); and focal intracytoplasmic mucin was seen only in large cell or mixed type. As a group, the 2-year disease-specific survival for patients with HGNEC was 25.4% (median follow-up time, 11.3 mo). No significant survival difference was observed among the different histologic subtypes. In conclusion, our study demonstrates the existence of both small cell and nonsmall cell types of HGNEC in the GI tract, and provides a detailed illustration of their morphologic spectrum. There are differences in certain pathologic features between small cell and nonsmall cell types, whereas the differences between the subtypes of nonsmall cell category (large cell versus mixed) are less distinct. Given the current uncertainty as to whether large cell neuroendocrine carcinoma is as chemosensitive as small cell carcinoma even in the lung, our data provide further evidence in favor of a dichotomous classification scheme (small cell vs. nonsmall cell) for HGNEC of the GI tract. Separation of nonsmall cell type into large cell and mixed subtypes may not be necessary. These tumors are clinically aggressive. Prospective studies using defined diagnostic criteria are needed to determine their biologic characteristics and optimal management.

INTRODUCTION: Stricture is a common complication in Crohn's disease (CD). Accurate identification of strictures that poorly respond to biologic therapy is essential for making optimal therapeutic decisions. The aim of this study was to determine the association between ultrasound characteristics of strictures and their therapeutic outcomes. METHODS: Consecutive CD patients with symptomatic strictures scheduled for biologic therapy were retrospectively recruited at a tertiary hospital. Baseline intestinal ultrasound was conducted to assess stricture characteristics, including bowel wall thickness, length, stratification, vascularity, and creeping fat wrapping angle. Patients were followed up for a minimum of 1 year, during which long-term outcomes including surgery, steroid-free clinical remission, and mucosal healing were recorded. Statistical analyses were performed. RESULTS: A total of 43 patients were enrolled. Strictures were located in the ileocecal region (39.5%), colon (37.2%), anastomosis (20.9%), and small intestine (2.3%). The median follow-up time was 17 months (interquartile range 7–25), with 27 patients (62.8%) undergoing surgery. On multivariant analysis, creeping fat wrapping angle > 180° (odds ratio: 6.2, 95% confidence interval [CI]: 1.1–41.1) and a high Limberg score (odds ratio: 2.3, 95% CI: 1.4–6.0) were independent predictors of surgery, with an area under the curve of 0.771 (95% CI: 0.602–0.940), accuracy of 83.7%, sensitivity of 96.3%, and specificity of 62.5%. On Cox survival analysis, creeping fat >180° was significantly associated with surgery (hazard ratio, 5.2; 95% CI: 1.2–21.8; P = 0.03). In addition, creeping fat was significantly associated with steroid-free clinical remission (P = 0.015) and mucosal healing (P = 0.06). DISCUSSION: Intestinal ultrasound characteristics can predict outcomes in patients with stricturing CD who undertook biologic therapy.

INTRODUCTION: Gastrointestinal ultrasound (GIUS) is recommended for monitoring Crohn's disease (CD). GIUS scores are used to quantify CD activity. Among them, International Bowel Ultrasound Segmental Activity Score (IBUS-SAS), Bowel Ultrasound Score (BUSS), Simple Ultrasound Score, and Simple Ultrasound Score for Crohn's Disease are most commonly used. The aim of this study was to compare and correlate the performance of such indicators with endoscopic activity and to calculate interobserver agreement. METHODS: Consecutive patients with CD at our hospital between June 2015 and July 2021 were retrospectively enrolled. All patients underwent ileocolonoscopy after medical treatment. GIUS was performed within 2 weeks, and 4 GIUS scores were independently calculated. Receiver operating characteristic curve analyses were used to determine a cutoff value. Cohen kappa (κ) coefficient was calculated to estimate the agreement between GIUS findings. RESULTS: A total of 106 patients with CD were enrolled. 80.2% (85/106) were endoscopic active (Simple Endoscopic Score for Crohn's disease ≥3), and 8.49% (9/106) were severe cases (Simple Endoscopic Score for Crohn's disease ≥9). All GIUS features (bowel wall thickness, color Doppler signs, bowel wall stratification, inflammatory signals at the mesentery) were statistically significant in assessing CD activity (P < 0.05). IBUS-SAS showed the highest area under the curve (0.98; 95% CI: 0.96–1.00) and specificity (95.2%) for a cutoff value of 46.50. However, IBUS-SAS had only moderate agreement (Cohen κ = 0.427; P < 0.001). BUSS had substantial interobserver agreement (Cohen κ = 0.947; P < 0.001), with a similar diagnostic value (sensitivity, 100.0%; accuracy, 95.3%; area under the curve of 0.96 [95% CI: 0.91–1.00] for a cutoff value of 4.58). DISCUSSION: GIUS score is an efficient and reliable method to assess CD activity. BUSS achieved a high accuracy and excellent interobserver agreement, which is more suitable for treatment assessment.

Background: The value of intestinal ultrasound (IUS) in predicting treatment outcomes in ulcerative colitis (UC) remains underexplored. Objectives: To compare the predictive accuracy of representative IUS scores for long-term endoscopic outcomes in UC. Design: A retrospective observational study. Methods: Consecutive UC patients initiating biologics/small-molecule drugs were enrolled. IUS examinations were performed at baseline, 4–6 months, and at the first colonoscopy reassessment (12–30 months). IUS images were reviewed, and bowel wall thickness (BWT), Milan ultrasound criteria (MUC), and International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) were recorded. Endoscopic response was assessed using the Mayo Endoscopic Score (MES), with remission defined as MES = 0 and improvement as MES ⩽1. Results: Forty-nine patients were included. All three IUS scores showed significant correlations with concurrent MES, with IBUS-SAS demonstrating the strongest association (BWT, ρ = 0.54; MUC, ρ = 0.55; IBUS-SAS, ρ = 0.69). IBUS-SAS at 4–6 months was the most accurate predictor of long-term endoscopic remission (area under the curve (AUC) 0.767) and endoscopic improvement (AUC 0.770). On multivariable analysis, an IBUS-SAS score <25.5 at 4–6 months was the only independent predictor of endoscopic remission (odds ratio (OR) 7.6, p = 0.005), while an IBUS-SAS score <38.0 was the only independent predictor of endoscopic improvement (OR 5.8, p = 0.006). Conclusion: The IBUS-SAS score at early follow-up may serve as a valuable predictor of long-term endoscopic outcomes in UC.

Background: Accurate assessment of hidradenitis suppurativa (HS) severity is crucial for individualized management, yet conventional clinical grading may underestimate disease extent due to subclinical lesions. Ultrasound enables visualization of deep abscesses and tunnels and may provide additional prognostic information. Materials and Methods: Sixty‐eight patients with HS underwent standardized clinical and ultrasonographic evaluation. Disease severity was classified using the International Hidradenitis Suppurativa Severity Score System (IHS4) and the modified Sonographic Scoring of HS (mSOS‐HS). Concordance between the two systems was assessed, and ultrasonographic grading and features were analyzed in relation to achievement of IHS4‐55 at week 12. Results: The mSOS‐HS classified 18 patients (26.5%) as having more severe disease than IHS4. The two grading systems showed statistically significant agreement, with the Kappa value approaching the threshold for moderate agreement (Kappa = 0.395, 95% CI: 0.204–0.586, p < 0.001). Patients with higher mSOS‐HS grades were less likely to achieve IHS4‐55 at week 12 ( p = 0.014). Among specific ultrasonographic features, the railway sign, defined as parallel hyperechoic lines within tunnel‐like structures, was significantly associated with failure to achieve IHS4‐55 ( p = 0.003). Conclusion: Ultrasonography reveals subclinical HS involvement beyond clinical examination and provides prognostic information for treatment response. The mSOS‐HS complements IHS4 for comprehensive disease staging, while the railway sign may serve as an imaging biomarker for unfavorable response across real‐world treatment settings.