Primary Posterior Fossa Hydatid Cyst in a Child

Abstract

Different surgical approaches were described to access the intra-orbital cysts based on the location of the cyst and the surgeon's experience. We usually use lateral orbitotomy with lateral orbital wall removal and replacement for excision of an intraconal orbital mass located lateral to the optic nerve. There is a concept that the cystic lesions should be excised intact to decrease the recurrence rate. In this case, although the cyst wall was very thin and opened at the final stages of the surgery, it was removed completely.Histopathology of an apocrine hidrocystoma was vastly described in the medical literature. 5,6,9,10 The apocrine hidrocystoma is a cyst with numerous small papillary projections that are lined by epithelial cells. The epithelium consists of a single or double layer of cuboidal to columnar cells lying on a layer of myoepithelial cells. The inner layer is composed of the eosinophilic cells with apical snouts or decapitation secretion. In our case, the cyst wall was composed of a double layer epithelium with an internal layer of cuboidal cells exhibiting apical snouts.In this case, there were some amblyogenic factors such as anisometropia and optic nerve compression. The patient underwent amblyopia therapy with glasses and contralateral occlusion therapy at the first visit and continued after the surgery. The glasses adjusted two weeks and three months after the surgery based on the new cycloplegic refraction. Anisometropia did not completely improve even 7 months after the cyst excision. Previous studies showed that in the significantly induced hypermetropia, excision of an intraconal lesion does not completely improve the hypermetropia because of the irreversible scleral changes. 13 In conclusion, an intraconal apocrine cyst may be a potentially sight-threatening lesion in infancy. In addition to ''as early as possible'' excision of the cyst, cycloplegic refraction and amblyopia therapy are important before and after surgery in this age group.