Pigmented Papules on the Face, Neck, and Chest

The Diagnosis: Syringoma

Syringomas are benign adnexal tumors with distinct histopathologic features, including the characteristic comma- or tadpole-shaped tail comprised of dilated cystic eccrine ducts. Clinically, syringomas typically present predominantly in the periorbital region in adolescent girls. They may present as solitary or multiple lesions, and sites such as the genital area, palms, scalp, and chest rarely can be involved.¹ Eruptive syringoma is a clinical subtype of syringoma that is seen on the face, neck, chest, and axillae that predominantly occurs in females with skin of color in countries such as Asia and Africa before or during puberty.^2,3 Lesions appear as small, flesh-colored or slightly pigmented, flat-topped papules.³ The condition can be cosmetically disfiguring and difficult to treat, especially in patients with darker skin.

FIGURE 1. A, Dermoscopic evaluation revealed reticular light brown lines, structureless light brown areas, and reticular vessels on a faint background (original magnification ×10). B, Glittering yellow-whitish round structures over a fading pink-brown background also were seen at some sites (original magnification ×10).

In our patient, dermoscopic evaluation revealed reticular light brown lines, structureless light brown areas, clustered brown dots, globules, and reticular vessels on a faint background (Figure 1A). Glittering yellow-whitish round structures over a fading pink-brown background also were seen at some sites (Figure 1B). Histologic examination of a neck lesion revealed an epidermis with focal acanthosis; the upper dermis had tumor islands and ducts with cells with round to vesicular nuclei and eosinophilic cytoplasm. A well-circumscribed tumor in the dermis composed of tubules of varying sizes lined by cuboidal cells was seen, consistent with syringoma (Figure 2).

FIGURE 2. Biopsy of a neck lesion showed a well-circumscribed tumor in the dermis composed of varying size tubules, which were lined by cuboidal cells with round to vesicular nuclei and eosinophilic cytoplasm, characteristic of syringoma (H&E, original magnification ×100).

Dermoscopic features of syringomas have not been widely studied. Hayashi et al⁴ reported the dermoscopic features of unilateral linear syringomas as a delicate and faint reticular pigmentation network and multiple hypopigmented areas. Sakiyama et al⁵ also defined an incomplete pigment network with faint erythema in 2 eruptive syringoma cases.

Treatment of this condition is for cosmetic reasons only, and there are no reports of long-term morbidity associated with the disease.^6,7 Multiple therapeutic options are available but are associated with complications such as hyperpigmentation and sclerosis in patients with skin of color due to the dermal location of these syringomas. Management of syringomas includes topical and surgical methods, including topical retinoids such as tretinoin and atropine solution 1%; surgical methods include dermabrasion, excision, cryotherapy, electrocautery, electrofulguration, laser therapy, and chemical cautery. However, there is a substantial risk for recurrence with these treatment options. In a case series of 5 patients with periorbital syringomas, treatment using radiofrequency and a CO₂ laser was performed with favorable outcomes, highlighting the use of combination therapies for treatment.8 Seo et al⁹ reported a retrospective case series of 92 patients with periorbital syringomas in which they treated one group with CO₂ laser and the other with botulinum toxin A injection; CO₂ laser combined with botulinum toxin A showed a greater effect than laser treatment alone. The differential diagnosis includes pigmented plane warts, sebaceous hyperplasia, eruptive xanthomas, and hidrocystomas. Pigmented plane warts characteristically present as flat-topped papules with small hemorrhagic dots or tiny pinpoint vessels on dermoscopy. In sebaceous hyperplasia, yellowish umbilicated papular lesions are seen with crown vessels on dermoscopy. Eruptive xanthomas usually are erythematous to yellow, dome-shaped papules that appear mainly over the extensor aspects of the extremities. Hidrocystoma presents as a solitary translucent larger syringomalike lesion commonly seen in the periorbital region and/or on the cheeks.

We report a case of widespread syringomas with multiple close mimickers such as pigmented plane warts; however, dermoscopy of the lesions helped to arrive at the diagnosis. Dermatologists should be aware of this condition and its benign nature to ensure correct diagnosis and appropriate treatment.