[Palpebral hidrocystoma]

Palpebral hidrocystomas are benign tumors also known as cystic apocrine adenoma, cyst of sweat gland, apocrine retention cyst or cyst of Moll. They originate from eccrine or apocrine sweat glands and often occur on the face and the eyelids. Other atypical locations such as the chest, the shoulders and the foreskin have been reported. Hidrocystoma is a small translucent, shiny cyst. It appears as single or multiple cystic lesion. Their histogenesis is uncertain. Indeed, apocrine hidrocystoma could arise from the residuals of the primitive apocrine glands or of the gland of Moll. The eccrine hidrocystoma could arise from the eccrine glands or the excretory duct of the glands of Moll. Their clinical differentiation is little obvious and diagnosis is based on histological examination. They are characterized by two clinical presentations: isolated hidrocystomas and the associated types. Isolated hidrocystoma is the most common type: hidrocystoma appears as single or multiple cystic lesions and it is not associated with extraocular signs. Apocrine hidrocystomas are solitary in 93% of cases while eccrine hidrocystomas appear most often as multiple lesions. The associated types are more rare and have been only described for the multiple hidrocystomas. If in the majority of cases a treatment based on argon laser is sufficient, more voluminous hidrocystomas require surgical resection. We here report the case of a young patient presenting with translucent nodule in the external canthus of the left eye. Hidrocystoma, molluscum pendulum and syringoma were the suspected diagnoses. Surgical resection was performed as well as histologic examination which confirmed the diagnosis of hidrocystoma.