Density of Biopsy Sampling Required to Ensure Accurate Histological Assessment of Inflammation in Active Ulcerative Colitis.

BACKGROUND: Histological response to treatment is an important outcome in patients with ulcerative colitis (UC). The accuracy of biopsy-based measurements of inflammation may be limited by error imposed by natural microscopic heterogeneity on the scale of individual biopsies. We determined the magnitude of this error, its histological correlates, and the density of biopsy sampling within mucosal regions of interest required to meet specified benchmarks for accuracy. METHODS: A total of 994 sequential 1-mm digital microscopic images (virtual biopsies) from consecutive colectomies from patients with clinically severe UC were scored by 2 pathologists. Agreement statistics for Geboes subscores and Nancy (NHI) and Robarts Histological Indices (RHI) between random samples from 1 to 10 biopsies and a reference mean score across a 2-cm region of mucosa were calculated using bootstrapping with 2500 iterations. RESULTS: The agreement statistics improved across all indices as the biopsy density increased, with the largest proportional gains occurring with addition of the second and third biopsies. One biopsy achieved moderate to good agreement with 95% confidence for NHI and RHI corresponding to scale-specific errors of 0.40 (0.25-0.66) and 3.02 (2.08-5.36), respectively; and 3 biopsies achieved good agreement with 95% confidence corresponding to scale-specific errors of 0.22 (0.14-0.39) and 1.87 (1.19-3.25), respectively. Of the individual histological features, erosions and ulcers had the greatest impact on the agreement statistics. CONCLUSIONS: In the setting of active colitis, up to 3 biopsy samples per region of interest may be required to overcome microscopic heterogeneity and ensure accurate histological grading.

Management and disease outcome of type I gastric neuroendocrine tumors: the Mount Sinai experience.

BACKGROUND AND AIM: The incidence of gastric neuroendocrine tumors (NETs) has increased tenfold since the 1970s. Our aim was to describe the clinicopathologic profile, management, and outcomes of type I gastric NETs at The Mount Sinai Hospital. METHODS: From existing databases of the Mount Sinai Division of Gastrointestinal Pathology and the Carcinoid Cancer Foundation, we identified 56 patients with type I gastric NETs seen at The Mount Sinai Hospital from 1993 to 2012. We generated a comprehensive dataset encompassing demographic, clinical, endoscopic, and pathologic factors. Survival information was determined from medical records and the Social Security Death Index. Tumor-node-metastasis staging was conducted, and tumors were graded based on mitotic counts and Ki67 index. RESULTS: Median NET size was 3.0 mm; 55.8 % displayed multifocal disease. Stages I, II, III, and IV disease were observed in 83.8, 10.8, 5.4, and 0 %, respectively. Tumors were either low (69.7 %) or intermediate (30.3 %) grade. Furthermore, 3.6 % of patients developed gastric dysplasia, and 5.5 % had gastric adenocarcinoma. Patients underwent endoscopy every 15 months, while 28.6 % underwent polypectomy, 32.7 % somatostatin therapy, and 46.4 % surgical resection. 5- and 10-year disease-specific survival was 100 %. CONCLUSIONS: Most patients received annual endoscopic surveillance, with a minority undergoing surgical resection, though outcomes remained excellent independent of therapeutic approach. We identified a very low but real rate of loco-regional spread, despite the generally indolent behavior of type I gastric NETs. Several patients demonstrated concurrent dysplasia or adenocarcinoma, underscoring the efficacy of regular endoscopic management not only for gastric NETs, but also for dysplasia and adenocarcinoma.