[Covered rupture of periocular dermoid cysts. Clinico-histologic study]

Dermoid cysts are common periocular tumours that occur in childhood and can, in case of rupture, result in persistent granulomatous inflammation. Histologically signs of chronical inflammation of the wall of the dermoid cyst are occasionally found in dermoid cysts that show no clinical symptoms. The aim of this study is to analyze frequency and etiology of this inflammation.

The charts of 21 patients that were operated on because of a dermoid cyst at Heidelberg University Eye Hospital between 1986 and 1993 have been examined concerning anamnesis, clinical symptoms, localisation of the cyst and incidents during operation. The dermoid cysts were assessed macroscopically, and histologically by means of serial sections (three cuts every 200 microns).

Histologically 8 patients (38%), of which only one had clinical symptoms, showed an inflammation of the wall of the cyst. The serial histological sections revealed a hidden rupture, that is a damage of the epithelium with a remaining pseudo-capsule of connective tissue, in these 8 patients. Hidden ruptures occurred proportionately most often at the age of 20 to 40. All cysts with a volume of more than 2197 mm3 showed a hidden rupture.

Hidden ruptures seem to be the reason for inflammations of the wall of a dermoid cyst. By way of the rupture, the content of the cyst gets into contact with the surrounding tissue, which results in a granulomatous reaction to the foreign body with remaining pseudo-capsule, to begin with. Etiologically a hidden rupture is promoted by the growth of the dermoid cyst and the pubertal enlargement of the sebaceous glands in the wall of the cyst. As a hidden rupture may result in a complete one with corresponding clinical symptoms, and as the risk to rupture a cyst during operation is higher in case of a cyst with hidden rupture, we recommend an early operative removal of dermoid cysts, if possible at the age of 3 or 4, but at least within the first 10 years.