RESUMO
Barrett's esophagus is premalignant for adenocarcinoma of the esophagus and esophagogastric junction. In 1998, the American College of Gastroenterology defined Barrett's esophagus as a change in the esophageal epithelium of any length that can be recognized at endoscopy and is confirmed to have intestinal metaplasia by biopsy of the esophagus. Metaplasia is followed by a series of histopathological changes, namely dysplasia, carcinoma in situ and finally leading to the development of adenocarcinoma. Dysplastic squamous epithelium is frequently found adjacent to the cancer and prospective follow up studies, particularly in areas of high incidence, have documented the progression of dysplasia to carcinoma. The aim of this work is to study histological types and grades of esophageal precancerous epithelial lesions. The study included seventy [70] cases of precancerous esophageal lesions diagnosed by endoscopic biopsy, at the pathology department of Gasroenterolgy Center, Mansoura University, in the period between January 1996 and December 2005. Sixty seven [67] cases of esophageal carcinoma, diagnosed by surgical resected specimens, were also studied during the same period to assess the presence or absence of associated precancerous lesions namely Barrett esophagus, squamous or glandular dysplasia. The paraffin blocks were sectioned at 4-5 microns and stained by Haematoxyline and Eosin for diagnosis of Barrett's esophagus, detection of dysplasia and its grades. Alcian blue stain at PH 2.5 was employed for staining of cases of Barrett's esophagus to confirm the diagnosis by staining acid mucins in the Goblet cells. Periodic acid Schiff was used to stain neutral mucins and the brush border of intestinal absorptive cells. Cases with squamous dysplasia were diagnosed and its grades were assessed. In cases of esophageal carcinoma, diagnosis of tumor type using the WHO classification [2000] was done. The presence or absence of associated Barrett esophagus, squamous or glandular dysplasia was evaluated. Results of the endoscopic biopsies: This study included seventy [70] cases of precancerous esophageal lesions. Forty six cases were Barrett's esophagus and twenty four cases were squamous dysplasia. In the 46 cases of Barrett's esophagus, Seven cases [15.23%] showed complete intestinal metaplasia in the form of goblet cells and non secretory absorptive cells and thirty five cases [76.08%] showed incomplete intestinal metaplasia diagnosed by PAS positive mucin in the columner cells. Four cases [8.69%] showed mixture of complete and incomplete intestinal metaplsia. Both Barrett's esophagus and squamous dysplasia showed male predilection as male to female ratio was 1.9:1 and 1.4:1 respectively. The age range for Barrett's esophagus was 23-63 years with a mean age of 45.41 +/- 8.94 For squamous dysplasia, the age ranged from 32 to 65 years with a mean age of 48.88 +/- 12.88. 21 cases of Barrett's esophagus were negative for dysplasia with a percentage of 45.65% while 6 cases were indefinite for dysplasia [13.04%]. Low grade dysplasia was diagnosed in 10 cases [21.73%], high grade dysplasia in 7 cases [15.23%] and intramucosal carcinoma in 2 cases [4.35%]. Nine cases of squamous dysplasia wore of moderate grade [37.50%] while eight cases [33.33%] were of severe grade. Five cases [20.83%] were of mild grade. Carcinoma in situ was diagnosed in two cases. Results of the resected specimens: Squamous cell carcinoma had the highest incidence with a percentage of 53.73% [36 cases], while adenocarcioma represented 38.82% [26 cases] of the total number of cases. 53.85% [14 cases] of the adenocarcinomas in the study were associated with Barrett's esophagus and 46.15% [12 cases] were not. Squamous dysplasia was found in 61.11% [22 cases] of the squamous cell carcinoma cases, while 38.89% [14 cases] of squamous cell carcinoma was not associated with squamous dysplasia. The diagnosis of precancerous Lesions of the esophagus is of utmost importance as cancer esophagus is characterized by poor prognosis but it is curable in its earliest stages. Successful early detection strategies require identification of precancerous lesions that can be targets for screening and treatment