After taking a short break, let’s continue to explain the surgical problems we frequently encounter in children.  The fact that the topics I explained in the Pediatric Surgeon’s Journal reach people, enlighten them, and the positive feedbacks make me very happy.
Today, I will tell you about a pathology that I encounter very often.  In fact, it is a painless, usually 1-3 cm in size, rubbery cystic structure under the skin, which is present since birth, but which may not be noticed until 3-4 months of age because of its small size, located just below or above the outer half of the eyebrow.  We, pediatric surgeons, can make the diagnosis as soon as we see it.  Dermoid cyst.  Sometimes it can also be called an angular cyst.
While we are still in the embryonic period, three layers are formed first;  ectoderm, mesoderm and endoderm.  Our structures such as our skin, nails, hair, and teeth develop from the ectoderm layer, where the outermost organs develop.  If some of the elements consisting of this layer remain in a sac under the skin, a benign skin develop anomaly, a dermoid cyst, is formed.  The skin elements in the sac continue to work, the trapped glands continue to secrete fluid, the cyst grows slowly.
Although they are congenital problems, only about 40% of them are seen at birth, more often they start to become noticeable in childhood after they start to grow slowly.  It can be seen in many parts of the body, the most common, up to 85%, is located in the head and neck region.  In the head and neck region, as you can see in the image in my youtube video, it is most noticeable on the outer third of the eyebrow.  However, dermoid cysts can develop anywhere in the body.
We don’t know exactly why and how they form.  We only know that the skin structures are trapped under the skin during fetal development.  In other words, there are structures such as fat, epithelial cells, hairs, tooth fragments in the vesicles.  There’s no gender, age, or race connection.  Although slightly more reported in white girls, it is not statistically significant.  After all, they account for almost 50% of childhood scalp tumors.
Especially in those that develop in the midline, for example, in the middle of both eyebrows, just above the nose, growth into the head can also be seen.  Since we know that they can grow into the head or into the spinal cord depending on the location, we definitely do the necessary imaging studies before starting any treatment process.  We stay away from interventions such as needle biopsy and needle aspiration because undesirable conditions such as infection, osteomyelitis, brain abscess, meningitis may occur.
Since dermoid cysts grow slowly, infection may develop, and they may cause problems such as bone deformity and mass formation in the brain, we prefer to completely remove the outer sac, as you can see in the photos on the youtube video.  Sometimes they can become abscessed and empty spontaneously, but if the capsule around them does not come out, they form again.  The younger we remove it, the easier the surgery will be, and the smaller the scar that will remain.  Likewise, if there is a dermoid cyst in the ovaries, we remove it by laparoscopy, if possible, while preserving the ovary.  I will explain ovarian and ovarian cysts in another course.  Dermoid cysts, which are connected to the spinal cord and have open channels such as fistulas, where the cerebrospinal fluid comes out, are evaluated and treated by neurosurgeons.
If there is no extension into the brain, if the cyst is completely removed with its sac, the treatment is completed.  The probability of malignant cells in the pathology specimen is very low.  Those in the ovaries or abdomen or sublingual are more likely to have malignant cells.  
As a result, we call the swellings on the outer third of the eyebrow “dermoid cyst”.  We recommend that these congenital structures be removed under general anesthesia in the operating room at a suitable time before they start to cause bleeding, inflammation, and local problems due to infection, trauma.
We have come to the end of our journey.
If you like the video, subscribe to my youtube channel and click like if you enjoyed, follow us on instagram.
And stay happy.
September 2022
Prof.  Dr.  Egemen Eroglu