BACKGROUND No residual disease (NRD) can be found in the specimen after endoscopic resection (ER) of biopsy-proven gastric neoplasm. This study aimed to evaluate the endoscopic and pathologic characteristics of patients with NRD and identify the cause and long-term prognosis.

METHODS Medical records of patients who underwent ER for biopsy-proven gastric neoplasms at a single tertiary hospital between January 2005 and November 2014 were retrospectively reviewed. Patients whose post-ER histology was revealed as NRD were included. Overall incidence, clinicopathologic characteristics, cause, and long-term prognosis were analyzed.

RESULTS NRD was detected in 143 (3.2%) of 4401 cases of gastric neoplasms treated with ER. Mean endoscopic size of the initial lesion was 8.15 ± 6.64 mm; in 93 cases (65.0%), the lesion was located in the lower third of the stomach. Initial pathologic diagnosis was as follows: adenoma (n = 110), carcinoma (n = 29), and atypical gland (n = 4). The causes of NRD were minute lesions removed by biopsy in 140 patients, pathologic misdiagnoses in two, and localization error in one. Local recurrence was detected in five patients (3.6%) with minute lesions during follow-up and treated with argon plasma coagulation (n = 4) or re-ER (n = 1). Synchronous (n = 5, 3.6%) and metachronous gastric lesions (n = 6, 4.3%) were also detected during follow-up.

CONCLUSIONS The main cause of NRD was minute lesions which might be completely removed by initial diagnostic biopsy. These cases showed a minimal rate of local recurrence and synchronous or metachronous gastric neoplasms. Careful follow-up is also mandatory for detection of residual disease.