A visible mass of cancer cells in the lumen of the bronchial dissection is usually a surgical term and may indicate a positive margin of excision. The effect of resection and the margin of resection for malignant tumors can be differently calibrated as R0, R1, and R2 resections.R0 resection represents complete resection of the tumor with a negative microscopic margin, i.e., no tumor residue.R1 resection is a resection in which the tumor is not visible under the naked eye but is visible under the microscope. R1 resection means that the tumor is not visible under the naked eye, but the tumor residue can be seen under the microscope.R2 resection means that the tumor residue can be seen under the naked eye after the resection procedure.R2 resection means that the tumor residue can be seen under the naked eye after the resection procedure. The visible mass of cancer cells in the lumen of the bronchial segment may indicate a positive margin, with the possibility of R1 and R2 resection, which is an incomplete surgery. When cancer cell mass is visible in the lumen of bronchial severance, the patient needs to follow the doctor to check the situation, and the patient goes to the hospital for treatment in time.