David M. Frim, MD, PhD, University of Chicago, presents case studies of skin deformities in children that lead to neurological congenital anomalies such as myelodysplasia, encephalocele, and skin erosion of implants.
Today I'd like to give one of my favorite talks. It's an important area in neurosurgery. But one that certainly has some elements of the unknown to it. And it's entitled Neurosurgical Lumps, Bumps, Pocks, and Divots, which are really cutaneous manifestations of a neurosurgical disease. Just to introduce it-- though technically challenging to correct some of these problems on the inside, many of the congenital anomalies that we see as neurosurgeons that are eventually operated, are found on the outside by primary care physicians, or even dermatologists. And many of those primary care physicians are the pediatrician. These diagnoses and then the referrals oftentimes require prompt and recognition of what the cutaneous stigma is, and then what potential diagnostic problems can come from that. And these include things like myelodysplasia, or the spinal cord and the spine being abnormal. Encephalocele, where parts of the brain can be outside of the head. Various skin erosion of implants. Trauma. A variety of other problems. I'll give a few examples here, and showing a picture, and eventually a short description. Here's something on the back of a child. She's four years old. She has no symptoms. Just a red splotch. And that could represent a number of things. In this situation, we obtained an MRI scan that shows-- though not at the level of the lesion-- this subcutaneous track, that you can see going from the skin surface in the lumbar region, angled down to the spine. And in fact, when we operated on it, we can see that there was a small tail of tissue that went from the skin, which is on the right side of the operative picture, through the bones of the lamina of the spine, and all the way to the spinal cord itself. This is called-- in this situation-- a lumbar subcutaneous dermal sinus tract, leading to a tethered cord. As we know, tethered cord syndrome-- oftentimes called occult spinal dysraphism-- is believed to occur in about one in 1,000 to one in 10,000 live births. Over half of those children will have some sort of cutaneous stigma. This variability in the number and the severity of the accompanying symptoms-- outcome is quite good after surgical repair. And the incidence is probably decreasing, presumed secondary to the folic acid treatment, and the knowledge of these by antenatal ultrasound. Here's another lesion on the face in this young child. If you look below the black shield over the eyes at the nose, what you see is that small pit, which wasn't noticed when the child was born. It was noticed shortly thereafter. An MRI scan was obtained. And as you can see, the pit led to a small area under the nose that was a dermoid. Nasal pit with a sinus tract below, leading to a nasal dermoid cyst is not very common. A pit can occur anywhere from the midline underneath the nose to the glabella. Sometimes it's nothing but a pit, meaning there's nothing underneath. But it can be tracked into a dermoid cyst. That can be anywhere along the midline of the face, especially above the glabella. And it can be representative of nasal frontal encephalocele, or other complicated congenital anomalies. Here's a lesion on the upper back. It seems a little bit more than a pit, almost a little slit in the skin. An MRI was obtained that showed that it was in fact a cervical thoracic tether, where there was a track growing out of the back of the spinal cord, as you can see, in between the bones of the cervical spine, causing traction on the spinal cord and in fact tethering of the spinal cord in that area. And that also required a repair to release the tether. Here's a little bit closer view of it, and how it emanates from the spinal cord all the way to the skin, where that small pit was. Here's a lesion noted at birth on this child. Though this is a short time afterwards. At three months of age, he had this bump, covered by a little bit of hair, but surrounded by hair. And the bump on the back of the head had been slowly growing, as the child was growing. Here's a look with the hair shaved, with a small hemangiomatous changes around it, and then the hair growing out of the middle of it. And there are a number of things that this could be. Here's a CT scan. Shows the mass and a very small opening in the bone-- seemingly too small to contain an encephalocele, and not on the midline, like most encephaloceles. At the time of surgery, it turned out that this was a large hemangioma. And as you see, that area where there was a hole in the brain, on the left side, is where that small vein was going into the skull from the hemangioma. The right side shows the final closure after the skin was intersected with lesion. So occipital hemangioma, not rare, though usually small in size and reddish. Generally in the midline, but it can be in the lateral position. It's a vascular lesion that if disrupted can result in significant bleeding, especially in an infant or a newborn child. And most, perhaps up to 80%, will involute spontaneously by age five years. Here's an infant with a bump on the top back of the head, with a swirl of hair around it. A lot of things this could also be. So we obtained an MRI scan that showed a hole in the bone, and this tissue from the brain traversing from inside the skull to insert on the skin underneath the area that we see, from the scalp. We operated to remove the area of abnormal skin and the tissue underneath it, until we got all the way down to the skull, where there was that small defect. And where brain tissue, though nonfunctional, had pushed its way out of the skull and attached to the skin underneath, where in a sense it was dragged out further. We were able to truncate it at the skull and just leave that small defect there. And to close the skin over it. And the child was essentially normal after that. So this is an occipital encephalocele, though it's atretic, meaning that it seemed to be somewhat, in a sense, dehydrated and twisted upon itself. Some people would call it a dermal sinus tract of the skull. It's a form of what I call cranial dysraphism. It's nearly always in the midline. And it can occur from the tip of the nose to the upper cervical spine. It's generally surrounded by skin discoloration, with what is termed the hairy halo, where the hair is around it and grows abnormally quickly. And it always communicates to the meninges. It requires repair because of the risk of meningitis. Because there is a communication from the area under the skin all the way to the cerebral spinal fluid of the brain. Skin breakdown in that area that can be of some risk. Here's a small pit on the back that actually looked like this before being shaved. It's called the lumbar hairy patch in an 18-year-old male. Another view of it. In the end, it turns out to be a small dimple where the skin is abnormal. The plain X-ray shows the bifid spine in the sacrum, where you see the bones not coming together in the midline. The MRI scan shows the elongation of the spinal cord all the way down to lumbar level number four, and its communication to a fatty mass that communicates under the skin. So is this is a mild dysplastic cutaneous stigma. Some people would call a lumbosacral dimple with a track and a hairy patch. In this case, it's associated with a neural tube defect that, with the fatty changes in the spinal cord, is formally called lipomyelomeningocele. It likely is associated with tethered cord syndrome, as in this case. And after the workup with the MRI scan, this young man was taken to the operating room for a repair of his tethered cord. Here's another infant. And if you look above the black shade put over his eyes, you see this bump. And the bump is right over the anterior fontanelle, which can represent a number of things. An MRI scan was obtained, which showed this mass emanating right at the edge of the fontanelle, with some sort of high protein material inside of it. This turned out to be a dermoid cyst of the scalp, benign lesion of course. That was enlarging as the baby grew. These dermoids occur at bone sutures, though anywhere on the skull, at the anterior fontanelle, at the coronal suture off to the side, or posteriorly at the posterior fontanelle or the lambdoid sutures. They can grow or they can progress. The treatment is essentially a diagnostic biopsy which is excisional, mostly for cosmesis or discomfort, once the diagnosis is made. Every so often though, one of these lesions occurs at the level of the torcula, and then can go transcranially into the posterior fossa, which makes the removal much more complicated. This is another interesting lesion. A 16-year-old football player with a bump on the back of the head. The X-rays just showed a bony protuberance there. A CT scan also showed bony protuberance, with normal anatomy underneath. It was removed and found to be a benign skull osteoma, which essentially is a callus formation of the bony surface, to form a palpable mass. This had to do with this young man being a football player with a tight helmet. Because it's noted at sites of what I call massage, meaning the football helmet pressure at the level of the inion at the back of the head, causing the bone callus to form and begin to protrude, and essentially making the football helmet that much more uncomfortable. We removed this for comfort, as well as for the cosmesis. And he was able to return to football playing without much trouble. Here's something that can be quite dramatic when a child is born. This was a protuberance coming just off the midline in a child, noted at birth. It was attached to the skin. And was able to be lifted up to show that it enters into the skin quite near the midline, above the gluteal fold. An MRI scan showed that it went into the skin and seemed to connect no deeper than the bony structures below. This is what's termed the literature a human tail, in a sense a striking stigma of occult spinal dysraphism. The MRI scan, in addition to showing the lesion, showed a low-lying tethered cord. At surgery, the tail base emanated from the tethered spinal cord filum terminale through the subcutaneous fat. It went all the way to the tail. The filum was sectioned. The tail was cosmetically removed by the plastic surgery team. And in fact, the child has done very well, with no apparent problems from this or the tethered cord. Thank you very much I think that's the end of this review of these very interesting skin abnormalities that are neurosurgical in nature.
