A must-read for parents: Is intracranial arachnoid cyst really an “invisible bomb”?

Author: Tian Yongji, Chief Physician, Beijing Tiantan Hospital, Capital Medical University

Reviewer: Li Jingjing, Chief Physician, Beijing Tiantan Hospital, Capital Medical University

The brain is undoubtedly one of the most mysterious and critical parts of the human body. However, sometimes seemingly minor lesions, such as intracranial arachnoid cysts, can cause concern among parents.

1. The truth about intracranial arachnoid cysts

Intracranial arachnoid cyst, as the name implies, is a cyst that occurs in the arachnoid membrane of the skull. In terms of biological characteristics, it is considered a benign intracranial lesion, which is fundamentally different from a malignant tumor. The cause of this cyst is still inconclusive. It is currently believed to be related to congenital factors or trauma. Some patients may already have cysts at birth, while some patients may not have obvious cysts at birth, but they gradually increase in size as they grow and develop.

Figure 1 Original copyright image, no permission to reprint

Scientists have proposed a variety of hypotheses about its cause. On the one hand, it may originate from abnormalities in the development of the nervous system, such as the presence of other neural structural defects (such as the absence of the corpus callosum); on the other hand, early mild brain damage leading to arachnoid damage is also considered a possible mechanism for the formation of cysts. However, despite the many opinions, intracranial arachnoid cysts are still widely recognized as a congenital benign lesion.

Among parents' concerns, whether intracranial arachnoid cysts will transform into malignant ones is an important issue. However, current research evidence shows that intracranial arachnoid cysts maintain their benign characteristics, and there are no reports in the literature that they can progress to malignant tumors or other malignant diseases. Therefore, we can clearly say that such cysts usually do not develop into malignant lesions over time.

2. Impact and diagnosis of intracranial arachnoid cysts

Congenital intracranial arachnoid cysts usually do not cause obvious clinical discomfort, and most patients are found by accident during trauma or physical examination. However, this does not mean that we can completely ignore its existence, because for some children, intracranial arachnoid cysts may increase in size.

Research in this area has been done abroad, in which children aged from birth to 5 years old were divided into 4 groups: 0-0.5 years old, 0.5-1 years old, 1-3 years old, and 3-5 years old. These children with arachnoid cysts were then followed up, and it was found that arachnoid cysts were more likely to grow larger in children in the younger age groups.

That is to say, if an arachnoid cyst is diagnosed in an infant younger than 1 year old, the cyst is more likely to grow as the brain grows rapidly. However, if an arachnoid cyst is found in a child aged 3-5 years old, the probability of it continuing to expand is relatively small.

Figure 2 Original copyright image, no permission to reprint

In terms of diagnosis, intracranial arachnoid cysts mainly rely on cranial magnetic resonance imaging (MRI). This examination can clearly show the location, size and relationship of the cyst with surrounding tissues, providing doctors with accurate diagnostic basis. In addition, MRI examination can also distinguish whether the contents of the cyst are cerebrospinal fluid, tumors or other congenital substances, improving the accuracy of diagnosis.

In terms of symptoms, intracranial arachnoid cysts have no obvious symptoms in most cases. However, some children may show symptoms such as local skull bulge and epileptic seizures. For the appearance of these symptoms, parents should take their children to see a doctor in time so that the doctor can develop an appropriate treatment plan based on the specific situation.

3. How should parents deal with intracranial arachnoid cysts

Parents often feel anxious and worried when their children are diagnosed with intracranial arachnoid cysts. However, we need to understand that intracranial arachnoid cysts are benign lesions and usually do not have a substantial impact on children's intelligence and height. Therefore, parents do not need to worry or be overly nervous.

In daily life, parents do not need to overly restrict their children's activities. A foreign study showed that children with intracranial arachnoid cysts do not increase the risk of intracranial hemorrhage when participating in sports. Therefore, children can participate in sports activities normally and enjoy a happy childhood.

Of course, regular follow-up is essential. Doctors usually recommend a cranial MRI every six months, one year, or two years, depending on the child's age, to dynamically monitor whether the cyst has changed. For cases where localized skull bulging can be observed, parents can learn to measure the head circumference and record it at a fixed time each month to observe whether there are significant changes in the bulging area. These records will provide important reference information for doctors.

Finally, parents need to maintain a rational attitude towards the disease of intracranial arachnoid cysts. Avoid passing unnecessary anxiety to children, so as not to affect their mental health and growth. At the same time, pay attention to the mental health of children, provide care and support for children, and help them face their "intracranial cysts" correctly.