A fluid-filled papule at the corner of the eye

Hidrocystomas (HCs) are benign, cystic, tumor-like lesions presenting as translucent nodules.1,2 HCs are classified into two major subtypes depending on their origin: eccrine or apocrine sweat gland ducts. These lesions occur predominantly in adults aged between 30 and 75 years,...

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Hidrocystomas (HCs) are benign, cystic, tumor-like lesions presenting as translucent nodules.^1,2 HCs are
classified into two major subtypes depending on their origin: eccrine or apocrine sweat gland ducts.

These lesions occur predominantly in adults aged between 30 and 75 years, and they affect both sexes equally.^1-4 They grow slowly, persist indefinitely, and do not exhibit familial inheritance patterns.⁴

Although the exact pathogenesis of adult-onset HC is unclear, it is hypothesized that occlusion of the sweat duct apparatus results in sweat retention and a dilated cystic structure.^1,2,4

Clinically, eccrine and apocrine HCs present similarly as solitary dome-shaped papules containing watery fluid.^4-6 These nodules may be translucent, transparent, or bluish-black, due to the Tyndall phenomenon.⁶ Lesions most commonly occur along the inner canthus of the eyelid margin, as well as other locations on the head and neck containing sweat glands.^1,4-6 In rare cases, HCs may also occur on the chest, shoulder, axillae, groin, and nipple.^4,6

Although HCs are usually solitary, they may also occur in groups and are occasionally associated with inherited syndromes.^4,6 Multiple apocrine HCs of the eyelids are associated with Schöpf-Schulz-Passarge syndrome, an autosomal recessive condition causing palmoplantar hyperkeratosis, hypodontia, and hypotrichosis.^4,6 Multiple periocular apocrine HCs are also associated with the X-linked dominant condition Goltz-Gorlin syndrome (also known as focal dermal hypoplasia), which causes microcephaly, midfacial hypoplasia, malformed ears, papillomas of the lips, tongue, axilla, and anus, skeletal abnormalities, and mental retardation.^4,6

Diagnosis of HC is clinical; however, biopsy results aid confirmation and are required to distinguish between the apocrine and eccrine subtypes.⁴ Decapitation secretion is the hallmark of apocrine HCs.^1,6 Histologically, apocrine HCs appear as large unilocular or multilocular cystic spaces in the dermis with a double lining of epithelium.^2,3,6 The lining consists of a double layer of epithelial cells.^2,3,6 The outer layer consists of flattened myoepithelial cells and the inner layer consists of tall columnar to cuboidal cells with eosinophilic cytoplasm and round or oval vesicular nuclei at the base.^2,3,6 Periodic acid-Schiff-positive granules may be seen in the cytoplasm of the inner lining.^3,6 Approximately 50% of apocrine HCs have small papillary projections growing into the central cavity.^3,6 In contrast, eccrine HCs appear as unilocular cysts composed of one to two layers of cuboidal cells and lack papillary projections.⁵

The differential diagnosis includes lesions that may appear similar clinically but lack the apocrine-like secretory epithelium.² These include cystic pleomorphic adenomas, Warthin tumors, cystadenomas and cystadenocarcinomas, mucoepidermoid carcinoma, and mucous retention cysts.² HCs may also be difficult to distinguish from basal cell carcinomas and melanomas and may require biopsy.^2,3 Sclerosing polycystic adenosis may appear histomorphologically similar to apocrine HCs, but lesions of sclerosing polycystic adenosis are differentiated by their classic histologic features of nodular sclerosis and xanthomatous infiltrate.²

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The most common approach to treatment of HCs consists of a simple needle puncture.^4,6 However, patients with multiple lesions do not respond well to this treatment and lesions often recur after several weeks.^3,6 In these cases, electrodessication is an effective treatment.⁶ Providers may also prescribe topical 1% atropine; however, the anticholinergic side effects may be unacceptable.^4,6 Other potentially successful therapies include carbon dioxide laser vaporization and trichloroacetic acid application.⁴

In our case, the patient had a single HC and desired quick resolution. She was successfully treated with a simple needle puncture.

Melinda Liu, BA, is a medical student and Maura Holcomb, MD, is a dermatology resident at Baylor College of Medicine in Houston.

References

1. Mukherjee B, Desai A, Krishnakumar S, Biswas J. A giant apocrine hidrocystoma presenting as lacrimal gland mass. Orbit. 2015;34:342-344.
2. Kikuchi K, Fukunaga S, Inoue H, Miyazaki Y, Ide F, Kusama K. Apocrine hidrocystoma of the lower lip: a case report and literature review. Head Neck Pathol. 2014;8:117-121.
3. Sarabi K, Khachemoune A. Hidrocystomas—a brief review. MedGenMed. 2006;8(3):57.
4. Ovhal AG, Deshkulakarani SV, Abhange RS, Birare SD. Rare benign cystic lesions on face: apocrine hidrocystoma. Indian J Dermatol. 2016;61:237.
5. Behshad S, Weil NC, Ho ST, Mayhall GK, Valenzuela AA. A cyst you can’t miss: a rare presentation of an orbital apocrine hidrocystoma. Orbit. 2015;34(4):229-231.
6. Verma SB. Multiple apocrine hidrocystomas: a confusing clinical diagnosis. An Bras Dermatol. 2010;85:260-263.