Description

• Hidrocystomas, also known as cystadenomas or sudoriferous cysts, are rare, benign cystic growths of sweat glands (1).
• Typically present as solitary nodules, but multiple hidrocystomas do occur
• Most commonly found on the face, predominantly the eyelid (glands of Moll); may also occur on forehead or cheeks; occasionally found on scalp, ears, chest, shoulders, axillae, external genitalia, and feet
• Can be of apocrine or eccrine in origin. The term “ductal hidrocystoma” is a neutral diagnostic term in reference to both kinds (1).
• Eccrine hidrocystomas are further subdivided into “Robinson-type” (multiple eccrine hidrocystomas) or “Smith-type” (solitary eccrine hidrocystomas) (1).
• Can differentiate apocrine from eccrine hidrocystoma both clinically and histopathologically (2)

Epidemiology

• Eccrine and apocrine hidrocystomas affect adults between 30 and 70 years of age; apocrine hidrocystomas can occur in childhood and adolescence (1).
• Solitary eccrine hidrocystomas are equally prevalent among males and females.
• Multiple eccrine hidrocystomas affect females more than males (1).

Prevalence
Prevalence is unknown. However, hidrocystomas account for ~1/1,000 submitted cutaneous biopsies (2).

Etiology and Pathophysiology

Obstruction of the apocrine or eccrine sweat gland following an inflammatory process, trauma, or portal closure (3):

• Multiple eccrine hidrocystomas may be caused or worsened by hot and humid environments, worsening in summer months and improving in cooler weather.
• Etiology of single eccrine hidrocystomas, or single or multiple hidrocystomas, is unknown.

• Schöpf-Schulz-Passarge, an inherited autosomal recessive condition, is characterized by multiple apocrine eyelid hidrocystomas along with ectodermal dysplasia, causing palmar hyperkeratosis, hypodontia, and hypotrichosis (1).
• Goltz-Gorlin (Jessner-Cole syndrome), a sporadic or X-linked dominant syndrome most often occurring in females, is characterized by microcephaly; midfacial hypoplasia; malformed ears; microphthalmia; periocular multiple hidrocystomas; papillomas of the lip, tongue, anus, and axilla; skeletal abnormalities; and mental retardation (1).

Risk Factors

Multiple eccrine hidrocystomas may be caused or worsened by exposure to hot, humid environments.

Commonly Associated Conditions

• Associated with Schöpf-Schulz-Passarge syndrome and Goltz-Gorlin syndrome (rare)
• Multiple eccrine hidrocystomas have been associated with Graves disease (rare).
• Multiple eccrine hidrocystomas have been associated with Parkinson disease (rare).