Low-grade malignancy is a pathological concept that refers to tumors with less cellular heterogeneity and more differentiation. Low-grade malignant tumors have a lower risk of lymph node and multi-organ metastasis and a better prognosis. In pathological concepts, low-grade malignancy is defined in terms of the degree of differentiation of tumor cells; the higher the degree of differentiation, the lower the degree of malignancy; conversely, the lower the degree of differentiation, the higher the degree of malignancy. The degree of differentiation of tumor cells includes four types: undifferentiated, low differentiated, moderately differentiated and highly differentiated. Low-grade malignant tumors have a higher degree of cell differentiation. In general, low-grade malignant tumors are less likely to have abnormal lymph node and distant organ metastases, and the first-line antitumor treatment modalities are more sensitive and have a better overall prognosis. Although low-grade malignant tumors are less malignant tumors, they still need to be taken seriously, and once diagnosed, they need to be treated aggressively in accordance with the doctor’s instructions, maintain a good attitude towards treatment, and improve the quality of life.