| Theme |
Colorectal cancer in ulcerative colitis |
| Title |
Biopsy diagnosis of dysplasia and carcinoma in patients with ulcerative colitis |
| Author |
Yoichi Ajioka |
Division of Molecular and Functional Pathology, Graduate School of Medical and Dental Sciences, Niigata University |
| Author |
Hidenobu Watanabe |
Niigata University |
| Author |
Kazutaka Suda |
Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University |
| Author |
Yoichiro Baba |
Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University |
| Author |
Hiroki Shimizu |
Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University |
| Author |
Ken Nishikura |
Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University |
| Author |
Gen Watanabe |
Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University |
| [ Summary ] |
For biopsy diagnosis of atypical epithelium of the mucosa with ulcerative colitis (UC), evaluation of 1) phase of the inflammation, 2) proliferative cell kinetics, 3) cellular atypia, 4) p53 immunostaining pattern, and 5) clinical information on the gross appearance of the lesions, is important. When the background mucosa reveals the active phase of inflammation, re-biopsy in the remission phase is required and definite diagnosis should not be made until this is done. An atypical epithelium in the non-active phase of inflammation can be classified into either the top-down morphogenic type or the bottom-up morphogenic type. In the case of the top-down type, an atypical epithelium may be judged to be carcinomial by the degree of cellular atypia. A differential diagnosis of dysplasia or sporadic adenoma can be made when observing a p53 immunostaining pattern and a macroscopic type. A p53 positive epithelium can be regarded as dysplasia while one with p53 negative and taken from a polypoid lesion can be diagnosed as being sporadic adenoma. In the case of the bottom-up type, which accounts for the majority of dysplasia cases, one should judge whether or not the cellular atypia of the epithelium is within the limits of what can be demonstrated in cases of inflammatory regenerative mucosa. Important findings such as nuclear chromatin pattern, uniformity of the nuclei, size and colour of the nucleoli, and presence of the golgi area in the cytoplasm help to make medical judgements. When an atypical epithelium is judged to be neoplastic, it can be diagnosed as dysplasia. For an indefinate diagnosis of neoplasia of the epithelium, evaluation of p53 immunostaining is essential. When over expression of p53 proteins is demonstrated, an atypical epithelium can be diagnosed as dysplasia. In some cases, p53 protein over expression is demonstrated within the epithelium without significant cellular atypia to suggest neoplasia. The clinical significance of such epithelium is not clear, but if it can be regarded as a high risk marker for further development of dysplasia, we must consider carrying out routine p53 immunostaining for all biopsy specimens which are obtained from surveillance colonoscopies. |