A case of ulcerative colitis with squamous cell carcinomas and multiple foci of squamous dysplasia.

Squamous cell carcinoma (SqCC) in ulcerative colitis (UC) is rare. A 38 year-old Japanese woman, who suffered from left-sided UC for 18 years, underwent total colectomy due to SqCCs in the rectum and the sigmoid colon. They were well differentiated SqCC, and metastasis was found in the paracolic lymph nodes. Multiple small foci of squamous dysplasia (SD) were noted in the rectal mucosa. Glandular dysplasia was not found. TP53 was not detected in SD. Approximately 40% of cells were immunostained with TP53 in SqCC, however no mutation was found in TP53 gene. Human papilloma virus and Epstein Barr virus were negative in SD and SqCCs. The patient is free of the disease at one and half years after surgery and chemotherapy. SD may be a precursor of SqCC. It appeared that TP53 does not play a vital role in the development of SqCCs in the current case. Careful attention should be paid to SD in UC patients. Viral infection may need to be examined. The pathogenesis of SqCC in patients of UC needs to be elucidated.