Let’s look at the story of a grandpa Zhang: Zhang is over 60 years old, usually has a wide range of hobbies, life has a taste. However, but often back and leg pain, usually on a plaster, rest for a day and a half will be fine. However, the recent attack of lumbar leg pain is more and more frequent, but also heavier, after the introduction of people around Zhang decided to tie acupuncture, massage. But insist on treatment for nearly half a year, lumbago not only not good, but also more and more heavy, daytime pain, more pain at night. After visiting the hospital, an MRI examination revealed that it was a crestal medullary tumor. What is myelomeningocele? Why did he get this disease? This man was finally found to have a cremaster medullary tumor. Before we talk about crestal myeloma, let’s take a look at what crestal myeloma is. The skeleton model in the picture below is made in the same scale as a 1.7 meter tall person. From the back of the head (rear view), the section from the back of the head to the sacral vertebrae below is called the crest, and the section of protrusions that can be felt by touching the back is called the spinous process. If you look at the crest from the front (anterior view), you can see that the front of the crest is a block of vertebrae linked by a fibrous ring, and the joint between each two vertebrae is the intervertebral disc. Most of the lumbar spondylosis and cervical spondylosis are problems with the intervertebral discs. From the side of the crest (side view), you can also see that the entire crest is not straight, but has multiple bends, the cervical and lumbar vertebrae bend forward, the thoracic and sacral vertebrae bend backward. These four bends allow the body to move backwards and forwards. In addition to this, yellow nerves, called crural nerves, can be seen from the side, drilling out of the crura. The nerves that emerge from the different segments are distributed throughout the body and are responsible for the motor and sensory functions of the corresponding areas. As a whole, a segment of vertebrae makes up the entire crestal column, and the intervertebral foramen, a small hole in the middle of the vertebrae, is linked together to form a long canal, the spinal canal. The spinal canal is wrapped in the crestal medulla and is connected to the brain. The signals from the brain are transmitted to all parts of the body through the crural medulla, which also collects activity signals from all parts of the body and is equivalent to a relay station where nerve electrical signals are transmitted back and forth like a courier boy. Therefore, if the cremaster nerve or cremaster medulla is affected, it will manifest as impaired motor and sensory function in the corresponding organ. The underlying cause of crestal medullary tumors is not fully understood, and it is clear that it is related to the body’s genes. It is not as severely affected by lifestyle such as sitting and sleeping posture as cervical or lumbar spondylosis. Why was it initially mistaken for lumbar spondylosis? Why would a crestal medullary tumor also cause lumbar pain? In this case, Zhang felt lumbar and leg pain in the early stage, and he thought it was normal to have lumbar and leg pain when he was old, at most it was cervical and lumbar spondylosis, and it was hard to think that it might be a problem of the crestal medulla and spinal canal. This is mainly because the incidence of cervical and lumbar spondylosis is very high, coupled with the fact that many people are always sedentary and do not exercise at work and study, almost 20% of people have cervical spondylosis and 10%-20% of people have lumbar spondylosis; while the incidence of tumor is relatively very low, only a few out of 100,000 people may have the disease, therefore, lumbar and leg pain and numbness can easily be considered as cervical spondylosis or lumbar spondylosis. So why do crestal medullary tumors also cause low back and leg pain? A crestal medullary tumor is a tumor that grows from the crestal medulla or the nerve roots surrounding the crestal medulla. When the tumor invades the crestal medulla or nerve roots, it causes pain or numbness. And pain or numbness can also occur in cervical and lumbar spondylosis, etc. Therefore, it is difficult to determine what the disease is in the early stage just by these symptoms.