Multiple eccrine hidrocystomas (MEH) are benign cystic lesions with a chronic clinical course and seasonal fluctuation. Treatment of MEH is often difficult due to the multiplicity of lesions and the risk of scarring and various treatments have been suggested, but there is still no gold standard treatment.
A 57-year-old woman presented with a 10-year history of bilateral translucent papules involving the periorbital areas and cheeks (Fig. 1a). The lesions were more pronounced in summer. She had oily skin and her medical and family histories were unremarkable. There was no history of trauma. Laboratory findings were normal. Dermatological examination revealed numerous dome-shaped, skin-colored, translucent lesions of 2–5 mm diameter in the centrofacial area. Histopathologically, the papular lesions had unilocular cystic structures within the dermis (Fig. 2a). The cyst walls consisted of two layers of small, cuboidal epithelial cells with round-to-oval nuclei and eosinophilic cytoplasm. Decapitation secretion and myoepithelial cells were not observed. Based on these findings, the patient was diagnosed with MEH. We began to treat the patient with oral isotretinoin 20 mg once a day to decrease severe seborrhea. By 6 weeks, there was marked improvement without any side-effects except mild cheilitis and dryness (Fig. 1b). Interestingly, a second biopsy revealed marked shrinkage of the cystic masses (Fig. 2b). Because the effects of isotretinoin usually last only a few months, we used an ultrapulse CO2 laser to reduce the MEH lesions and obtain a longer cosmetic effect. Immediately after discontinuing isotretinoin treatment, we irradiated the shrunken MEH lesions with an ultrapulse CO2 laser at 800 Watts, 20-Hz frequency and 0.3-msec pulse duration. Eventually, a good cosmetic result was achieved, and the patient was very satisfied (Fig. 1c). When we examined her the following summer, the good cosmetic result had been maintained except that seborrhea had recurred (Fig. 1d).
Isotretinoin has been approved for the treatment of various dermatological conditions including acne and psoriasis. More recently, it has been shown that retinoids decreased tumor progression in non-melanoma skin cancer. The exact mechanism of the antitumor action is not clear, but it has various biologic activities, including modulation of epithelial proliferation and differentiation, anti-seborrheic, anti-inflammatory and antitumor effects, and induction of apoptosis. Given this background, it has been used to treat several neoplastic conditions such as sebaceous hyperplasia, basal cell carcinoma and keratoacanthoma. However, there is no report of MEH treated with isotretinoin. We thought that it may be effective because of its diverse biologic actions, especially modulation of proliferation and differentiation. We gave the patient isotretinoin orally for 6 weeks, because that can be used to control the seborrhea. In addition, to obtain a longer cosmetic effect we used an ultrapulse CO2 laser in the next step. In fact, if we had used the CO2 laser first, this would have led to post-laser side-effects, because when ablative CO2 lasers are applied to skin lesions over 3 mm in diameter, scarring, ectropion and postinflammatory hypo- and hyperpigmentation have been reported.[3, 4] On the other hand, small, reduced lesions can be readily treated by CO2 laser without significant side effects. Of course, a single case cannot fully address the question as to whether or not combined therapy was more suitable than CO2 laser therapy alone. However, because the cystic space had been reduced histopathologically after isotretinoin treatment, we supposed that the epithelial cells in the cyst walls would be morphologically changed and more vulnerable to the CO2 laser.
This case provides an example of the efficacy of sequential treatment with oral isotretinoin and CO2 laser in a patient with MEH. We suggest that oral isotretinoin treatment could yield a good temporary cosmetic effect and the additional ablative laser treatment cause semi-permanent removal of the MEH lesions. However, further work is needed to establish exactly how isotretinoin acts on the MEH lesions. We suggest that our treatment regimen provides an alternative treatment option in difficult-to-treat patients with numerous EH lesions.