BACKGROUND: The malignant potential of superficial elevated type tumors is still controversial. Because biopsy specimens alone are sometimes not sufficient for diagnosis due to histologic heterogeneity within the tumor, other clinical parameters for evaluation of the degree of malignancy would be helpful. METHODS: A new morphometric parameter, the "F-circle," which represents the irregularity of the tumor margin, was studied in 115 endoscopically recognized superficial, flat, elevated type colorectal tumors without a central depressed area with respect to histologic evaluation of the degree of malignancy. RESULTS: The mean F-circle values of adenomatous lesions with mild or moderate atypia, severe atypia, and adenocarcinoma were 0.709+/-0.115, 0.619+/-0.149, and 0.536+/-0.133, respectively. CONCLUSION: The superficial elevated type of colorectal tumor having more marginal irregularity had a greater malignant potential, and the F-circle may be a useful clinical parameter for evaluation of the degree of malignancy.
BACKGROUND: The malignant potential of superficial elevated type tumors is still controversial. Because biopsy specimens alone are sometimes not sufficient for diagnosis due to histologic heterogeneity within the tumor, other clinical parameters for evaluation of the degree of malignancy would be helpful. METHODS: A new morphometric parameter, the "F-circle," which represents the irregularity of the tumor margin, was studied in 115 endoscopically recognized superficial, flat, elevated type colorectal tumors without a central depressed area with respect to histologic evaluation of the degree of malignancy. RESULTS: The mean F-circle values of adenomatous lesions with mild or moderate atypia, severe atypia, and adenocarcinoma were 0.709+/-0.115, 0.619+/-0.149, and 0.536+/-0.133, respectively. CONCLUSION: The superficial elevated type of colorectal tumor having more marginal irregularity had a greater malignant potential, and the F-circle may be a useful clinical parameter for evaluation of the degree of malignancy.