Syringomas
Christopher G. Bunick
Amanda Zubek
Macrene Alexiades
BACKGROUND
Syringomas are benign tumors of the sweat gland. Historically thought to be of eccrine origin, they may arise from either eccrine or apocrine elements. These lesions are more common in women and most commonly are found on the face in a periorbital distribution. Syringomas are often cosmetically distressing to the patient. Treatment of syringomas is based on destructive modalities and can be challenging because of frequent recurrence.
PRESENTATION
Patients present with solitary or multiple small asymptomatic or mildly itchy skin-colored bumps on the lower eyelids.
DIAGNOSIS
Clinical Diagnosis
Syringomas appear as small, ˜1 to 4 mm round, skin-colored to pink to yellow papules that can be distributed over a number of areas, including the face, axillae, umbilicus, upper chest, and vulva. They often occur in clusters and are predominantly found in women. Rarely, they present in an eruptive, or sudden, fashion. This presentation is most commonly associated with Down syndrome and less commonly with diabetes mellitus. When syringomas occur on the eyelid, they must be distinguished from benign xanthelasma or trichoepitheliomas, as well as from malignant basal cell carcinoma.1
Histopathology
Histologic examination of syringoma reveals multiple small tadpole-shaped nests and tubules in the superficial dermis within a sclerotic stroma. The nests are composed of cuboidal epithelial cells with ductal differentiation.2
Subtypes
Sporadic
Eruptive syringomas
Associated with diabetes mellitus
Associated with Down syndrome
Associated with Nicolau and Balus syndrome (along with milia and vermiculate atrophoderma)
Differential Diagnosis
Xanthelasma
Trichoadenoma
Desmoplastic trichoepithelioma
Sebaceous hyperplasia
Basal cell carcinoma
Microcystic adnexal carcinoma
PATHOGENESIS
Syringomas are a benign sweat duct tumor and histologically appear as “tadpole” or comma-shaped eccrine duct formations. The molecular pathways involved in their formation remain to be elucidated; however, it has been postulated that the mechanism for eruptive syringoma involves infiltration of CD4+ and CD8+ T cells leading to autoimmune destruction of the acrosyringium.3 This in turn leads to proliferation of dermal eccrine ducts and fibrous stroma.
TREATMENT
As is the case for any of the benign lesions in this chapter, a patient may opt for no treatment, making observation a perfectly acceptable choice. For those patients who desire cosmetic removal, the most promising and positively reviewed therapy for syringomas is CO2 laser1,4 (Algorithm 11.2.1). Several other lasers, such as erbium:YAG, have also been used with success. Any laser therapy near the eye requires the proper use of eye protection. Surgical techniques include dermabrasion, electrosurgery, and chemical peels, particularly trichloroacetic acid (TCA). TCA has been used in combination with laser therapy with good results.5,6 For alternatives to either laser or surgical approaches, topical and oral medications have had limited success in some patients. Oral tranilast has been used to successfully treat vulvar syringomas in Japan.7
Medical
Atropine
In one report, topical atropine 1% solution was used once daily (˜0.75 mL/d) to reduce pruritus and the size of syringomas in a 27-year-old woman. Atropine is known to reduce sweat secretion, but its mechanism of action on syringomas is not known.8
Retinoids
The data supporting the use of topical retinoids or oral retinoids in syringoma therapy are weak. One Spanish woman with eruptive syringomas over the trunk used tretinoin 0.05% to 0.1% cream once daily with some flattening and lightening of the syringomas after 4 months.9 There is a lack of other literature supporting topical retinoids as a truly effective therapy. Similarly, the use of oral isotretinoin has proven hit or miss, with a few patients benefiting and a few not, including the most recent failure of an Egyptian man on 5 months low-dose 10 mg/d oral isotretinoin.10