Syringoma (benign neoplasm of skin)

Are You Confident of the Diagnosis?

What you should be alert for in the history

Syringomas are benign adnexal neoplasms derived from the intraepidermal ductal portion of the eccrine gland. They are more common in women than men, and typically arise during puberty or early adulthood, although they may develop in prepubescent children or later adulthood as well. The lesions are most commonly found on the periocular and upper maxillary area of the face, with less frequent occurrences on the extremities, chest, abdomen, axillae, genitalia, and buttocks. Rarely, lesions may be found on the scalp, and have been associated with hair loss and scarring alopecia in these cases.

Characteristic findings on physical examination

Syringomas are usually asymptomatic, although pruritus has been described in some cases. On physical examination, they are usually seen as small, grouped, skin-colored to yellowish papules. Each lesion is characteristically 1-4mm, and they are usually distributed symmetrically (Figure 1).

Figure 1.

Classic lower eyelid syringomas

Atypical presentations may include giant syringomas (lesions measuring more than 5mm) (Figure 2) as well asunilateral and solitary syringomas, which may present as annular, linear, or plaque-type lesions (Figure 3). The majority of syringomas are sporadic, but some familial cases have been reported in which an autosomal dominant inheritance pattern was proposed.

Figure 2.

Giant syringomas

Figure 3.

Unilateral annular syringomas

Eruptive syringomas may present as the sudden appearance of multiple lesions, occurring in successive crops. Most of these cases occur during adolescence and involve the anterior trunk and extremities. It has recently been postulated that these cases may be due to inflammation-induced eccrine gland hyperplasia (rather than a neoplastic process).

Expected results of diagnostic studies

Diagnosis can be confirmed with a skin biopsy, as syringomas have a distinct histology. They consist of multiple ductular structures embedded within a fibrous stroma in the superficial dermis. Each of these ducts is lined by two rows of epithelial cells, with some forming tails to give the characteristic ’tadpole’ shape. Solid islands and strands of epithelial cells are also seen. Rarely, these cells may appear clear secondary to glycogen accumulation.

Diagnosis confirmation

Important entities in the histologic differential diagnosis that need to be excluded include: morpheaform basal cell carcinoma, desmoplastic trichoepithelioma, and microcystic adnexal carcinoma.

Who is at Risk for Developing this Disease?

Syringomas are very common lesions. They are more common in women than men, and typically arise during puberty or early adulthood, although they may develop in prepubescent children or later adulthood as well. Patients with Down syndrome, Marfan syndrome, and Ehlers-Danlos syndrome have a tendency to develop classical syringomas.

What is the Cause of the Disease?

While immunohistochemical studies of enzymes have demonstrated that syringomas are most likely eccrine-derived, their exact pathophysiology remains unclear. Due to their usual onset around puberty and reports of increased size during pregnancy and menstruation, it has been postulated that syringomas may be under hormonal control. Studies of estrogen and progesterone receptors have been performed, but with conflicting results. As stated above, an underlying inflammatory process may be responsible for eruptive lesions. There may also be familial cases with dominant inheritance.

Systemic Implications and Complications

There is a clear increased incidence of syringomas in patients with Down syndrome. These cases are usually classic periocular presentations, but eruptive syringomas in these patients have also been described. There is also reported to be an increased incidence of syringomas in Marfan and Ehlers-Danlos syndrome.

Eruptive syringomas have recently been associated with hyperthyroidism, so checking thyroid function studies (TSH, free T4) in these patients may be of value. Eruptive syringomas can also be seen in the context of Nicolau-Balus syndrome with milia and vermiculate atrophoderma.

The clear cell histologic variant of syringoma has been associated with diabetes mellitus, so checking a fasting blood glucose in these cases is warranted.

Treatment Options

Treatment options are summarized in the Table I.

Table I.
Medical treatment Surgical procedures
Topical tretinoin Excision
Topical atropine Electrocautery
Electrodessication and curettage
CO2 laser
Trichloroacetic acid

Optimal Therapeutic Approach for this Disease

Syringomas are benign lesions, and treatment is only necessary from a cosmetic standpoint. As medical therapies are generally ineffective and described only in a few isolated case reports, surgical modalities are the mainstay of treatment.

Topical tretinoin 0.1% gel qhs may be helpful in cases of eruptive syringomas, where surgical modalities may not be practical.

Topical atropine 1% qhs has been reported to improve pruritus in symptomatic lesions.

Surgical excision of syringomas can be accomplished with shave or scissor removal, followed by second intention healing.

Electrocautery can be used safely in patients with cardiac pacemakers or defibrillators.

Electrodessication, with or without curettage, has been reported as effective treatment, although hyperpigmentation can occur in darker skin types.

Ablative lasers, such as the CO2 laser, can be used alone, or in combination with a prior 35-50% trichloroacetic acid (TCA) chemical peel. Risks include scarring and hyperpigmentation, especially in darker skin types.

Cryosurgery and dermabrasion have also been used to treat syringomas, but may not be as effective as other options.

Patient Management

No follow-up is necessary if the patient does not desire treatment. They can simply be reassured as to the benign nature of these lesions.

If a topical therapy is prescribed, the patient may be seen back in 2-4 months to see the response to treatment.

Patients who want surgical treatment should be adequately counseled as to the efficacy and potential side effects of each modality. They will then have to make an informed decision based on the risk/benefit ratio whether they wish to proceed. Appropriate follow-up should be scheduled within 1-2 months to assess the efficacy of the treatment, post operative healing, and any side effects.

Unusual Clinical Scenarios to Consider in Patient Management

In cases of eruptive syringomas or those with clear cell histology on biopsy, labwork should be ordered, notably a TSH in the case of eruptive syringomas and a fasting glucose for patients with clear cell syringomas.

When considering therapies, take into account the Fitzpatrick skin type of the patient. For patients with darker skin (types IV-VI), there may be a higher incidence of keloid formation after surgical excision. These patients are also at higher risk for dyspigmentation after other procedures such as electrosurgery, ablative laser therapy, chemical peels, or cryosurgery.

What is the Evidence?

Patrizi, A, Neri, I, Marzaduri, S, Varotti, E, Passarini, B. “Syringoma. a review of twenty-nine cases”. Acta Derm Venereol. vol. 78. 1998. pp. 460-2. (A good review of the classic presentation of syringomas as well as some atypical cases.)

Halpern, A, Heymann, WR. “Unilateral Volar Annular Syringomata”. Cutis. vol. 79. 2007. pp. 369-370. (A case report.)

Ong, G, Lim, K, Chian, L. “Eruptive syringoma in a patient with trisomy 21”. Singapore Med J. vol. 51. 2010. pp. 46-47. (Discussion of the usual presentation of eruptive syringomas and their associated conditions.)

Petersson, F, Mjonberg, P, Kazakov, D, Bisceglia, M. “Eruptive Syringoma of the Penis: A report of 2 cases and a review of the literature”. Am J Dermatopathol. vol. 31. 2009. pp. 436-8. (Another good review of eruptive syringomas.)

Polat, M, Pelitli, A, Oztas, P, Unal, T, Alli, N. “Eruptive syringoma associated with hyperthyroidism”. Skinmed. vol. 8. 2010. pp. 124-5. (A case report.)

Maloney, ME. “An easy method for removal of syringoma”. J Dermatol Surg Oncol. vol. 8. 1982. pp. 973-5. (Photographic demonstration of scissor removal of periorbital syringomas.)

Stevenson, TR, Swanson, SA. “Syringoma: removal by electrodessication and curettage”. Am Plast Surg. vol. 15. 1985. pp. 151-4. (Description and illustration of the technique of elecrodessication and currettage in the treatment of syringomas.)

Kang, H, Kim, NS, Kim, YB, Shim, WC. “A new treatment for syringoma. Combination of carbon dioxide laser and trichloroacetic acid”. Dermatologic Surgery. vol. 24. 1998. pp. 1370-4. (A study of the efficacy of CO2 laser plus 50% TCA for the treatment of periorbital syringomas.)

Sanchez, TS, Dauden, E, Casas, AP, Garcia-Diez, A. “Eruptive pruritic syringomas: treatment with topical atropine”. J Am Acad Dermatol. vol. 44. 2001. pp. 148-9. (A case report.)

Gomez, MI, Perez, B, Azana, JM, Nunez, M, Ledo, A. “Eruptive syringoma: treatment with topical tretinoin”. Dermatology. vol. 189. 1994. pp. 105-6. (A case report.)