About Spinal Dermoid and Epidermoid Cysts
Spinal dermoid and epidermoid cysts are benign masses lined by epithelium that contain skin structures like hair follicles or sebaceous glands. These masses can become trapped within the spinal cord as the nervous system develops before birth.
Spinal dermoid cysts are congenital, non-cancerous and, by themselves, rarely cause symptoms. It is possible that the cysts can compress the spinal cord or spinal nerves and will need to be surgically removed. Spinal dermoid cysts may be related to other spinal abnormalities.
Cysts are typically hollow, but in dermoid and epidermoid cysts a lining of skin cells sheds into the inside of the cyst causing it to gradually expand. The difference between the two types of cysts is the type of cells lining the cyst wall. Dermoid cysts contain skin cells, products of skin cells, and other components, while epidermoid cysts only contain simple skin cells.
These cysts are diagnosed in children more so than adults, but overall are rare. They can be present at birth or can develop later on in life.
Common Symptoms of Spinal Dermoid/Epidermoid Cysts
Dermoid and epidermoid cysts in the spine are known to cause symptoms as they grow larger and compress structures. Although it depends on the size of the cyst and location, some common symptoms include:
- Difficulty walking
- Loss of bladder control
- Pins and needles in the arms/legs
Diagnosis of Spinal Dermoid/Epidermoid Cysts
Spinal dermoid and epidermoid cysts are diagnosed through imaging studies.
- MRI scans – produce detailed images of structures inside the body, and sometimes use an intravenous dye to supply more information about cysts.
- CT scans – provide enhanced definition of bony structures and sometimes an intravenous dye is also used to provide more detail.
Treatment Options for Spinal Dermoid/Epidermoid Cysts
Surgical removal is the treatment option of choice for symptomatic spinal dermoid and epidermoid cysts with the goal of complete removal however this may not be possible, particularly if the cyst wall is adherent to normal nerve tissue. Under these circumstances the surgeon will remove as much of the cyst as possible.
- Laminectomy and microsurgical cyst resection – The bony roof of the spinal canal, known as the lamina, is removed to access the neural tube, known as the thecal sac. The thecal sac is opened and utilizing a microscope for enhanced visualization, specialized micro instruments, and microsurgical technique the cyst is removed.