Flat gastric polyps: results of forceps biopsy, endoscopic mucosal resection, and long-term follow-up

Histological examination of specimens obtained by forceps biopsy sampling of gastric polyps is of limited accuracy, and their management on this basis is therefore controversial. The aim of this prospective study was to assess the value of forceps biopsy sampling in establishing the correct diagnosis revealed by endoscopic mucosal resection (EMR). The complication rate of EMR was also determined.

Subjects with gastric polyps of epithelial origin, of at least 0.5 cm in diameter, and not associated with polyposis syndromes, were included in the study. Between 1994 and 2004, 56 gastric polyps in 44 patients (30 F, 14 M, mean age 67 years) met the inclusion criteria. Indigo carmine dye staining and electronic magnification were used in all cases. Following forceps biopsy sampling, 56 EMRs were performed. The histological results of the forceps biopsy and the resected specimens were analyzed.

The initial forceps biopsies identified in situ carcinoma in 3 cases, adenoma with no dysplasia in 19, adenoma with low-grade dysplasia in 2, adenoma with moderate-grade dysplasia in 6, adenoma with high-grade dysplasia in 7, and hyperplastic lesions in 19 cases. The histological examination of the resected polyps revealed in situ carcinoma in 5 cases, carcinoid in 1, gastrointestinal stromal tumor in 1, adenoma with no dysplasia in 14, adenoma with low-grade dysplasia in 3, adenoma with moderate-grade dysplasia in 9, adenoma with high-grade dysplasia in 1, hyperplastic lesions in 21, and no diagnosis in 1 case. Complete agreement between the histological results on the forceps biopsy sample and on the ectomized polyp was seen in only 31 (55.3%) polyps. There were important disagreements in 12 cases. In 14 neoplastic and 1 hyperplastic polyps, the degree of dysplasia seen on histological examination of the forceps biopsy specimens differed from that observed for the resected specimens. Post-mucosectomy bleeding was observed in 3 patients, all of whom were successfully treated endoscopically.

Forceps biopsy is not sufficiently reliable for the identification of gastric polyps. These lesions should be fully resected by EMR for a final diagnosis and (depending on the lesion size and type) possibly definitive treatment.