Atypical endoscopic features can be associated with metastasis in rectal carcinoid tumors

Background  Endoscopically, rectal carcinoids have a variety of sizes and features which may assist in determining treatment plans. The present study was performed to assess the relationship between endoscopic features and metastasis in rectal carcinoids. Methods  A total of 115 rectal carcinoids of 112 patients with rectal carcinoids were enrolled, and the medical records were retrospectively reviewed. All tumors were classified according to size (longest diameter), and then according to endoscopic features such as shape, color, and surface changes including depressions, erosion, and ulceration. The relationship between endoscopic features and metastasis was evaluated. Results  11 cases (9.6%) of the 115 rectal carcinoids presented with metastatic disease. Tumor size was associated with metastasis (p < 0.001). Endoscopic features associated with metastasis were tumor shape, surface change, and color (p < 0.001). Atypical endoscopic features occurred more frequently as the size of the tumor increased (p < 0.001). For tumors 10–19 mm in diameter, atypical surface change was associated with metastasis (p = 0.007). Conclusions  Endoscopic features were found to be associated with metastasis in rectal carcinoids. In particular, atypical surface change may be useful in determining treatment plans for tumors 10–19 mm in diameter.