The median nasal sinus and dermoid cyst.

The median nasal sinus and the dermoid cyst of the nose are relatively rare congenital anomalies. The most likely hypothesis for their ontogeny seems to be the retention of ectodermal fragments during closure of the anterior foramen of the neural tube early in embryonal development. The results of the surgical management of fourteen patients with a median dermoid cyst of the nose are discussed. Presenting symptoms were recurrent abscess formation on the dorsum of the nose, a secreting fistula in the median line of the dorsum of the nose, or meningitis. The draining site of the sinus varied less than the location of the dermoid cyst. Treatment consisted in radical excision in a quite stage, using the binocular microscope followed by primary reconstruction of nasal skeletal defects. Anomalies are due not only to development disturbances in the surrounding structures owing to the presence of the sinus and the cyst, but also to growth of the cyst and to infection. Partly for that reason, early surgical management is indicated. It should be preceded by proper radiological examination, because this can provide important clues as to the site of the dermoid cyst. If an endocranial extension has been established preoperatively, a combined ORL and neurosurgical operation is necessary.