Hidrocystomas - A Brief Review

Abstract

Hidrocystomas, eccrine and apocrine, are rare cystic lesions that form benign tumors of the sweat glands. In this clinical review, we present a “classic” case of hidrocystoma and review the main epidemiologic, histologic, and clinical features. We also review the effectiveness of experimental treatment methods and present information about associated syndromes and differential diagnosis, focusing especially on hidrocystomas' resemblance to basal cell carcinoma.

Case Report

A 69-year-old man presented to our office with a small, clear, cystic papule filled with watery fluid, which had been present for several months. The lesion was observed to be on his left upper eyelid and measured approximately 4 mm × 3 mm (Figure). The patient denied any diplopia, vision loss, or any other lesions on his face or body. His review of systems, personal and family histories were all normal or noncontributory. After diagnosing solitary eccrine hidrocystoma on the basis of the clinical evidence, we discussed Treatment options with our patient, including puncture and drainage of the lesion and surgical excision. The patient opted to return for follow-up observation for the time being, but agreed to consider further intervention should the lesion become symptomatic or more noticeable.

Figure.

Eccrine hidrocystoma.

Introduction

Hidrocystomas – rare, benign, cystic lesions of the skin – can be either eccrine or apocrine, and are often found on the head and neck region.

Eccrine hidrocystomas are small and tense thin-walled cysts, ranging from 1 to 6 mm in diameter, and can occur as single or multiple lesions.[1] They are found predominantly in adult females and are located mostly on the periorbital and malar regions.

Apocrine hidrocystomas arise from the proliferation of apocrine glands and are usually solitary, with a diameter of 3 to 15 mm.[1] Apocrine lesions are also found mostly on the head and neck and along the eyelid margin near the inner canthus.[2] Apocrine lesions are less likely than eccrine lesions to occur at periorbital regions; nevertheless, the general distribution of lesions tends to occur in similar locations on the body for apocrine and eccrine hidrocystomas.[1]

Although rare and typically asymptomatic, eccrine and apocrine hidrocystomas are often of interest to physicians of different specialties. When encountered by practitioners, the approach to these lesions is facilitated by the clinical recognition of the subtypes and knowledge about their management. Furthermore, their close resemblance to certain, more serious skin disorders such as basal cell carcinomas necessitates an understanding of the histology of each type of hidrocystoma for the purposes of differential diagnosis. Hence, in this brief review we present a simplified approach to the diagnosis and management of both types of hidrocystomas.

Epidemiology

Eccrine hidrocystomas are prevalent in adults between 30 and 70 years of age.[1] Solitary eccrine hidrocystomas are equally prevalent among males and females; however, the multiple eccrine hidrocystomas are mainly seen in female patients.[3]

Apocrine hidrocystomas affect the same age groups as do eccrine hidrocystomas, and rarely occur during childhood or adolescence. They can appear as single or multiple cystic lesions. Although a significant number of cases of multiple apocrine hidrocystomas have been reported in the literature, the multiple type is rare in the general population.[4]

Clinical Presentation

Eccrine hidrocystomas are benign tumors of sweat gland origin and are classified into 2 major groups: the Smith type, which is the most prevalent solitary type, and the Robinson, or multiple, type. They are typically dome-shaped, have an amber, brown, or bluish tint, and range from 1 to 6 mm in diameter. During hot or humid weather, these lesions will grow in size and/or multiply in number. Eccrine hidrocystomas usually do not involve the eyelid margin but rather are distributed around the eyelid skin; this, along with a lighter color presentation, typically differentiates it from the apocrine type.[1]

The clinical presentation of apocrine hidrocystomas is very similar to that described above. They appear as dome-shaped, solitary, clear, cystic nodules with a smooth surface, and the color varies, ranging from flesh-colored to blue-black. Although the solitary hidrocystoma is the most common clinical presentation, multiple lesions on the face and neck have been reported.[5] The cysts tend to stay asymptomatic and will follow a gradual course until a certain size is reached. There is no evidence of seasonal variations associated with apocrine hidrocystoma, whereas patients tend to present with eccrine hidrocystomas mostly during hot, humid weather.[6] The Table delineates the distinctions between the 2 types of hidrocystomas, as well as the similarities.

Table.

Differentiation Between Eccrine and Apocrine Hidrocystomas

	Eccrine Hidrocystomas	Apocrine Hidrocystomas
No. of lesions	Solitary or multiple	Primarily solitary (but occasionally manifesting as multiple lesions)
Color	Ranges from flesh-colored to light-blue tint	Ranges from dark-blue tint to black
Size	1 to 6 mm in diameter	3 to 15 mm in diameter
Age group affected	30-75 years	30-75 years
Gender distribution	More prevalent among females than among males	Females and males are affected in equal numbers
Epithelium types	1-2 layers of cuboidal epithelium	Single/double cuboidal-columnar epithelium
Stains	S-100 positive (solitary type), PAS negative	S-100 negative, PAS positive
Special cellular features	No decapitation of cells, no secretory cells	Decapitation of secretory cells, papillary projections seen under microscope
Body location	Malar, periorbital, chest, axilla, neck	Face, ears, head, chest, shoulders
Possible treatments	Puncture and drainage, electrodessication, carbon dioxide laser, anticholinergic topical creams; placement in cold temperature	Puncture and drainage, electrodessication, carbon dioxide laser, anticholinergic topical creams
Special features	Worse in hot, humid weather	No change with temperature

PAS = periodic acid-Schiff

Histology and Pathogenesis

Eccrine hidrocystomas usually result from dilation of cystic excretory eccrine glands due to retention of sweat and dilation or blockage of the sweat duct. Under the microscope, eccrine hidrocystomas appear as unilocular cysts, which usually contain a single cystic cavity composed of 1 or 2 layers of cuboidal cells. They are located within the mid-dermal to superficial layers of the skin, especially around the eyes. Unlike their apocrine counterpart, there are no secretory cells seen and decapitation of cells is not viewed under the microscope.[1] Histochemically, they stain positive for S100 protein (solitary type), whereas apocrine hidrocystomas do not. The cyst and epidermis do not communicate, and the periodic acid-Schiff (PAS)-positive granules are not observed.[1]

Apocrine hidrocystomas appear as unilocular or multilocular under the microscope. The cyst wall is composed of an inner layer of secretory columnar epithelium. The epithelium is either a single or double layer of cuboidal-columnar epithelium, which lies above an outer myoepithelial cell layer. PAS- positive granules are observed in the presence of lipofuscin granules. Apocrine hidrocystomas also encompass papillary projections, which are not usually seen in the eccrine hidrocystomas. These projections are vascular connective tissue, covered by the secretory epithelium. Papillary projections then appear on the lumen of the cysts as an outgrowth extension from the wall of the cyst.[2]

Associated Syndromes

The inherited disorders that are most commonly associated with the presence of multiple eccrine/apocrine hidrocystomas are Goltz-Gorlin syndrome and Schopf-Schulz-Passarge syndrome.

Goltz-Gorlin (also known as Jessner-Cole syndrome, or focal dermal hypoplasia) tends to occur sporadically, with few familial cases having X-linked dominant transmission; it occurs mostly in females. Its cardinal features are microcephaly; midfacial hypoplasia; malformed ears; microphthalmia; periocular multiple hidrocystomas; papillomas of the lip, tongue, anus, and axilla; skeleton abnormalities; and mental retardation.[7]

Schopf-Schulz-Passarge is an autosomal recessive syndrome characterized by multiple eyelid apocrine hidrocystoma, palmoplantar hyperkeratosis, hypodontia, and hypotrichosis. It is further characterized by hypotrichosis, cysts of the eyelids, and multiple periocular apocrine hidrocystomas.[8]

Graves' disease has also been associated with multiple eccrine hidrocystomas,[9] possibly due to hyperhidrosis, which is seen in hyperthyroid patients. This is further supported by the disappearance of lesions after treatment of hyperthyroidism.[9]

Differential Diagnosis

Eccrine hidrocystomas and apocrine hidrocystomas have a very similar presentation, and their distinction from other head and neck cyst-like lesions must ultimately be verified on biopsy and by careful examination under the microscope. For both types, cystic lesions such as epidermal inclusion cysts, mucoid cysts, hemangioma, and lymphangioma are considered in the differential. Attention is given to cysts (mostly apocrine hidrocystomas) that resemble basal cell carcinoma of the eyelid or malignant melanoma because of their color (typically blue-black). A biopsy of the lesions is very important to exclude these diagnoses.

Management

The most common approach to the treatment of hidrocystomas (eccrine and apocrine) is simple needle puncture. However, in the Robinson type, a simple needle puncture will not produce lasting improvement. Multiple-type lesions have been successfully treated with topical 1% atropine or scopolamine creams, although anticholinergic side effects could cause patients to discontinue the treatment.[10] Excision of hidrocystomas can lead to scars, and treatment involving incisions and drainage can lead to recurrence after 6 weeks; this can be overcome by cauterization and electrodessication of the cyst wall.[1]

Gupta and colleagues[4] reported the use of electrodessication to be successful in the treatment of multiple apocrine tumors of less than 1 cm in diameter. Other methods that have shown success have been carbon dioxide laser vaporization and laser treatment.[4] Tanzi and colleagues[11] effectively treated a patient with pulsed-dye treatment with a 585-nm laser, and no recurrence was observed after 18 months of treatment. Finally, avoiding hot temperatures or humid conditions will help prevent worsening of symptoms in patients diagnosed with eccrine-type hidrocystomas.

Conclusion

Hidrocystomas are benign cystic lesions that typically occur in the facial region. Eccrine and apocrine hidrocystomas comprise the 2 main groups. Their clinical diagnosis requires knowledge of their differentiating characteristics in order to rule out other benign cystic lesions, and a biopsy must be obtained for histologic study. Management of hidrocystomas mainly involves simple needle puncture; however, other treatments such as electrodessication, anticholinergic creams, carbon dioxide vaporization, and laser treatment have all shown success in treating different types of hidrocystomas.