Apocrine hidrocystoma
Apocrine hidrocystomas are benign cystic proliferations of the apocrine secretory glands. Apocrine hidrocystomas most commonly appear as solitary, soft, dome-shaped, translucent papules or nodules and most frequently are located on the eyelids, especially the inner canthus. Apocrine hidrocystomas grow slowly and usually persist indefinitely.
Pathophysiology
The exact stimulus for the development of an apocrine hidrocystoma is unknown. Plausible causes of the closely related eccrine hidrocystoma include occlusion or blockage of the sweat duct apparatus, which results in the retention of sweat and a dilated cystic structure.
Physical
Apocrine hidrocystomas usually occur as solitary translucent papules or nodules. Consistency is fluctuant and cystic. Size varies from a few millimeters to approximately 1.5 cm. Tumors occasionally manifest as multiple lesions, especially when of the eccrine hidrocystoma type.1,2,3
Apocrine hidrocystomas often appear tense and shiny. The coloration varies from flesh-colored to blue or black
Tumors have a predilection for the eyelid, particularly the inner canthus. Tumors may arise on other areas of the head, neck, and trunk.4 Tumors also have been reported to occur on the penis, in the axillae, and in the anal region.
Lesion edges are not well delineated but blend gradually into adjacent skin. Walls, although translucent, are sufficiently thick that they seldom rupture spontaneously.
When incised, apocrine hidrocystomas collapse, and a thin, clear, brownish, or blackish fluid is released. The fluid color of an apocrine hidrocystoma does not result from the presence of melanin or hemosiderin but may result either from the Tyndall phenomenon or the presence of lipofuscin pigment.
Cysts are mobile with palpation and transilluminate.
Apocrine hidrocystomas are not affected by variation in temperature (unlike eccrine hidrocystomas).
Causes
Although the origin of apocrine hidrocystomas is not known entirely, they are believed to be adenomatous cystic proliferations of the apocrine glands.
Treatment
Surgical Care
Apocrine hidrocystomas can be incised and drained; however, electrosurgical destruction of the cyst wall often is recommended to prevent recurrence. Punch, scissors, or elliptical excision also can remove tumors. Multiple apocrine hidrocystomas can be treated with carbon dioxide laser vaporization.5 Trichloroacetic acid has also been used.6 One report suggests that multiple or recurrent hidrocystomas may be amendable to botulinum toxin A injection, with improvement.7
