ABSTRACT
A 29-year-old female patient presented with a painless mass on her upper eyelid medially. She noticed the mass 4 years earlier and it had increased in size over time. She had no diplopia, eyelid swelling, skin lesion overlying the mass, or visual disturbances. On ocular examination, eye movements and funduscopy were normal. The mass was movable and painless with palpation. Magnetic resonance imaging with contrast showed a 12x8x7 mm well-circumscribed cystic lesion with no contrast dye appearance. Surgical removal was performed delicately and no capsular rupture occured. Pathological examination revealed an eccrine hidrocystoma. Our aim is to underline that eccrine hidrocystoma should be included in differential diagnosis of orbital masses.
Introduction
Hidrocystoma is a rare benign cutaneous cystic lesion originating from sweat glands (eccrine or apocrine). Hidrocystoma occurs predominantly in the head and neck region. Solitary lesions occur with equal frequency in both genders, while multiple lesions are more common in women.
Eccrine hidrocystomas may manifest as single or multiple small (1-6 mm in diameter), thin-walled cysts.1Lesions in the head/neck region are most often located in the periorbital/malar area.2Apocrine hidrocystomas are usually solitary and 3-15 mm in size.1In this case report we aimed to highlight that orbital eccrine hidrocystoma, though rare, should be included in the differential diagnosis of orbital lesions.
Discussion
Hidrocystomas in the periorbital region are often located in the eyelid and inner canthus.3
Apocrine sweat glands are limited to specific regions like the axilla, nipple, external ear, external genitalia and eyelids, while eccrine sweat glands are widely distributed across the body.4
Eccrine hidrocystoma was first described by Robinson5 and was classified according to lesion number as Robinson (multiple) or Smith (solitary) type. Eccrine hidrocystomas generally expand in summer and spontaneously regress in cooler weather.1
Hidrocystomas do not recur if total excision is achieved. Because eccrine hidrocystomas are usually subcutaneous, they are obvious and can be diagnosed even at very small sizes (1-6 mm).1Our patient had a mass with a maximum diameter of 15 mm; it was likely able to reach this size because it developed over 4 years within the orbit.
Other cystic lesions included in the differential diagnosis of eccrine hidrocystomas are follicular cysts, epidermal inclusion cysts, hemangioma, lymphangioma, apocrine hidrocystoma and eccrine acrospiroma.
Cases of ‘orbital apocrine hidrocystoma’ have been reported in the literature by Valenzuela and Heathcote6, Ssi-Yan-Kai and Pearson7, Vignes et al.8and Mehta et al.9
Valenzuela and Heathcote6 described a 47-year-old male patient with a 3-month history of a painless mass in the superomedial aspect of his left upper eyelid which was impinging on his peripheral visual field. Orbital computed tomography (CT) imaging revealed a 13x8 mm extraconal cystic mass in close proximity to the globe. Mass excision by anterior orbitotomy was planned, but due to the attachments of the mass to the superomedial orbit, the brown contents of the cyst were first removed, then the excised cyst wall was sent for histopathologic examination. The inner walls of the cyst were lined with columnar epithelium and the cells contained PAS (Periodic Acid Schiff)-positive material in the apical cytoplasm. The mass was determined to be consistent with orbital apocrine hidrocystoma.
In a case reported by Ssi-Yan-Kai and Pearson7 a 46-year-old woman had soft mass growing on the medial aspect of her right lower eyelid for several months. The mass had displaced the globe superolaterally, but the patient’s eye movements appeared normal. Orbital CT revealed an 18 mm mass. However, the cyst ruptured during surgical excision and was determined insufficient for histopathological examination. Two years later, orbital MRI performed due to recurrence revealed another 17.5 mm cystic mass, also located in the inferomedial aspect of the orbit, which was surgically excised with cyst capsule intact. On histopathological examination, the mass was reported as ‘benign apocrine hidrocystoma’.
Vignes et al.8reported the case of a 33-year-old male with an 18-month history of progressive swelling of his right eyelid. There was no pathology apparent in the eyelid other than edema. Visual acuity and eye movements were normal. An intraorbital extraconal cystic lesion was detected on orbital MRI. The mass was surgically excised and diagnosed as ‘apocrine hidrocystoma’ based on histopathological examination.
Mehta et al.9described a 65-year-old woman who presented complaining of ptosis starting 10 days earlier and a mass in her left upper eyelid. The patient had undergone eyelid repair 7 years earlier due to traumatic ptosis, but no ptosis or mass had been reported in an ocular examination 2 months earlier. Eye movements were restricted on upward gaze and levator function was 14 mm on the right and 5 mm on the left. A soft mass 1.5 mm in diameter could be palpated at the medial aspect of the left supraorbital margin. Orbital CT and ultrasonography were performed and the cystic mass was completely excised after dissecting its adhesions to the levator aponeurosis. Histopathologic examination was consistent ‘apocrine hidrocystoma (sudoriferous cyst)’. The authors attributed cyst development in this patient to one of two mechanisms: either superficial sweat gland cells were implanted in deeper tissues at the time of the injury, or some epithelial cells were implanted into deeper tissues during the eyelid surgery following the trauma, where they gradually proliferated to form a cyst.
To our knowledge, there are no reports of orbital eccrine hidrocystoma in the literature other than the case of a 14-year-old patient with giant eccrine hidrocystoma reported by Eslami et al.10That case involved a 3-month history of a painless mass in the right upper eyelid. The patient presented with diplopia, proptosis and ptosis. Orbital CT revealed a 1.5x1 cm oval mass in the superomedial aspect displacing the right globe inferolaterally. Total excision was performed by cutaneous incision. The mass was a giant eccrine hidrocystoma, 1x1x2.5 cm in size, encapsulated in fibrous connective tissue.
Our aim in this study was to emphasize that eccrine hidrocystomas, although rare, should be considered during differential diagnosis of orbital masses.
