Minghao (a pseudonym) didn't feel much pain when he headed a soccer ball during a match with his friends. But waking up the next morning with a stiff, aching neck offered an early sign that something was not quite right. One month after the incident, Minghao's entire body went numb, leading spinal experts to perform a biopsy and ultimately diagnose him with a malignant tumor on the second vertebra in his neck.