system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, RESULTS. Meshes: Biopsy, Colitis, Ulcerative, Colon, Humans, Immunohistochemistry, Ki-67 Antigen, Precancerous Conditions, Reproducibility of Results, Severity of Illness Index, Tumor Suppressor Protein p53.
user
Does immunohistochemical assessment of Ki67 and p53 expression assist the diagnosis and grading of ulcerative colitis-related dysplasia? Context: To assess whether Ki67 and p53 immunostaining may assist the diagnosis and grading of ulcerative colitis-related dysplasia. Location of Ki67 staining and location and intensity of p53 staining were assessed in ulcerative colitis (UC) cases showing the features of high-grade dysplasia (HGD, n = 14), low-grade dysplasia (LGD, n = 22), 'indefinite for dysplasia' (n = 12), or regenerative atypia (RA, n = 22). Good intra- and inter-observer reproducibilities were demonstrated in the performance of these assessments. All the dysplasia cases showed extension of Ki67 staining above the basal third of the crypt. Moderate intensity p53 staining was seen in 10/22 RA cases, but strong intensity p53 staining was seen only in cases of dysplasia. All the cases of HGD showed extension of Ki67 and p53 staining above the basal two thirds of the crypt.
assistant
Restriction of Ki67 staining to the basal third of the crypt appears to exclude a diagnosis of dysplasia whereas strong intensity p53 staining suggests a diagnosis of dysplasia. Restriction of Ki67 or p53 staining to the basal two-thirds of the crypt appears to exclude a diagnosis of HGD. Final Decision: yes