Is it cancer to grow a hard big bag on the back

Long hard back pack is not necessarily cancer, generally need further examination, such as B ultrasound, hematology examination, etc. to make a comprehensive judgment. Long back pack a lot of cases, such as lipoma, benign tumor, etc., including malignant tumor. If the back hard pack grows very rapidly in a short period of time, it may be malignant tumor, to cause attention, do further examination.