Due to the relatively low incidence of malignant tumors in children, parents and even non-specialist doctors do not have enough knowledge about them, thinking that only when they feel the lumps are tumors, and ignoring many early symptoms of the disease, which delays the early detection and treatment of the disease. Unbeknownst to them, some cancers such as leukemia do not necessarily produce lumps at the early stage of the disease; some do not, such as kidney and adrenal tumor lumps hidden in the body, the Department of ultrasound, CT and other instruments through the examination can not be detected. Early detection of disease clues is very important, and parents (especially mothers) are often the first to notice these clues. Parents should be highly vigilant for the following symptoms in children: ● Prolonged unexplained fever, especially if antiviral or antimicrobial treatments are ineffective; ● Progressively worsening anemia, pallor, and lethargy that are not due to malnutrition or parasites; ● Bleeding for unknown reasons, including bleeding from the gums, skin bleeds, or petechiae; ● Longer-term, persistent, or intermittent pain (headache, abdominal pain, arthralgias, etc.); ● Certain neurological symptoms, including bleeding from gums, bleeding spots or petechiae; and ● Certain neurologic symptoms. ● Certain neurological symptoms, such as headache, vomiting, unsteady walking, facial nerve palsy, convulsions, etc.; ● Visual disturbances (strabismus, exophthalmos, etc.); ● Enlarged liver and spleen; ● High or low white blood cells or decreased red blood cells or platelets on routine blood tests, etc.