Ms. Qi found a lesion in her brain by cranial MRI 5 months ago. At that time, she suspected a malignant brain tumor and underwent surgery to remove it under the recommendation of local doctors. However, strangely enough, the surgically removed specimen did not show clear tumor cells. This left the follow-up treatment in a dilemma. What kind of disease should be treated according to? If the treatment was according to the MRI suspected malignancy, but the pathological diagnosis of the surgically removed specimen did not support it. In other words, if a benign lesion is treated according to a malignant tumor, the patient has to endure unnecessary radiotherapy and chemotherapy, causing serious damage to the body. Moreover, even if one follows the malignant tumor, which malignant tumor treatment plan will be followed? On the other hand, if the patient does not need to treat the tumor according to the pathological diagnosis, what if the tumor is really a malignant tumor, it will delay the chance of treatment and will affect the patient’s treatment outcome. Could it be that there are tumor cells in the surgically removed specimen, but the pathologist missed them? So the patient came to our hospital with the pathology specimen of previous surgical resection for pathology consultation, but only the change of gliosis was seen, and again no tumor cells were seen, so the treatment was again in a dilemma. We analyzed the patient’s post-surgical MRI film and found that the lesion still showed more typical malignant tumor features. The reason why the pathological diagnosis could not be clarified was probably because the site of the extraction was not in the core area of the tumor, so it was difficult for the pathologist to diagnose. In order to solve this problem, we suggested the patient to operate again to remove more tumor tissues, so that on the one hand, there could be more core tumor tissue specimens for easy diagnosis, and on the other hand, the tumor volume could be reduced to improve the effect of subsequent treatment. After several months of tossing and turning, the patient understood the current treatment dilemma and chose to undergo surgery again, and was successfully discharged from the hospital after surgery. In this way, the patient can start regular radiotherapy to control the growth and recurrence of the tumor. Tumor diagnosis is based on pathological findings as the final criteria, not on imaging diagnosis such as MRI. Only based on the pathological diagnosis of tumor tissues can the best treatment plan for the cause of the disease be formulated. However, it is necessary to look at the pathological diagnosis results dialectically and exclude some disturbing and uncertain factors in the pathological diagnosis, so that the pathological diagnosis results can truly conform to the essence and truth of tumor.