HIDDEN RUPTURE OF PERIOCULAR DERMOID CYST S

Background Dermoid cysts are common periocular tumours that occur in c hildhood and can, in case of rupture, result in persistant granulomato us 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 freque ncy and etiology of this inflammation. Patients and methods The charts of 21 patients that were operated on because of a dermoid cyst at Hei delberg University Eye Hospital between 1986 and 1993 have been examin ed concerning anamnesis, clinical symptoms, localisation of the cyst a nd incidents during operation. The dermoid cysts were assessed macrosc opically, and histologically by means of serial sections (three cuts e very 200 mum). Results Histologically 8 patients (38%), of which only one had clinical symptoms, showed an inflammation of the wall of the c yst. The serial histological sections revealed a hidden rupture, that is a damage of the epithelium with a remaining pseudo-capsule of conne ctive tissue, in these 8 patients. Hidden ruptures occurred proportion ately most often at the age of 20 to 40. All cysts with a volume of mo re than 2197 mm3 showed a hidden rupture. Conclusions 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. Etiolog ically a hidden rupture is promoted by the growth of the dermoid cyst and the pubertal enlargement of the sebacous glands in the wall of the cyst. As a hidden rupture may result in a complete one with correspon ding clinical symptoms, and as the risk to rupture a cyst during opera tion 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.