Dermal sinus

The dermal (Engl. Dermal sinus) is a small congenital skin opening with a narrow passage and ends in contrast to the fistula in deeper tissue layers blind. Tufts of hair growing out of it are not infrequently observed. Like the meningocele , the dermal sinus is primarily located on the back on the midline in the lumbar vertebrae. In some cases the dermal sinus continues as a fibrous connective tissue cord into the spinal cord and in such cases is combined with a spina bifida occulta . In other cases, a lipoma or dermoid cyst is observed at the end of the passage .

In most cases, a dermal sinus is symptom-free . However, they represent a possible source of infection for the deeper tissue or even the spinal canal and in such cases are surgically rehabilitated. Under the light microscope they appear as small channels in collagenous connective tissue, which are lined with keratinizing squamous epithelium.