Skin nonmelanocytic tumor
Adnexal tumors
Sweat gland derived (apocrine & eccrine glands)
Syringoma


Minor changes: 16 March 2021

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PubMed Search: Syringoma skin[title] pathology

Aadil Ahmed, M.D.
Sara C. Shalin, M.D., Ph.D.
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Cite this page: Ahmed A, Shalin SC. Syringoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumornonmelanocyticsyringoma.html. Accessed June 23rd, 2021.
Definition / general
  • Benign adnexal neoplasm of sweat gland (eccrine) origin
  • Most common clinical presentation on lower eyelids of women
  • Appears to derive from sweat duct ridge
  • Malignant counterpart can be termed syringomatous carcinoma / sweat gland carcinoma
Essential features
  • Often multiple 1 - 4 mm, firm papules
  • Well circumscribed dermal lesion with comma shaped ductules lined by basaloid cells and with sclerotic stroma
ICD coding
  • ICD-10: D23.9 - other benign neoplasm of skin, unspecified
Epidemiology
  • F > M for all syringomas (J Am Acad Dermatol 2016;74:1234)
  • Typically occurs after puberty; most common during reproductive years (may be due to hormonal influence)
  • More common in people of Asian decent
  • Increased incidence in Down, Nicolau-Balus and Brook-Spiegler syndromes
  • Possible familial association (up to 20%)
Sites
Pathophysiology
Etiology
Clinical features
  • Generally asymptomatic
  • Vulvar syringomas often present with pruritus and are often bilateral (J Am Acad Dermatol 2003;48:735)
  • Oral contraceptive pills or menstruation may worsen symptoms or increase lesion size
  • Symptoms may worsen in summer
  • Clinical variants
    • Localized
    • Generalized
      • Multifocal
      • Eruptive
    • Down syndrome
    • Familial
Diagnosis
  • On face, in particular, can be clinically suspected
  • Biopsy required for confirmation
Prognostic factors
  • Benign, nonprogressive lesions but can be cosmetically bothersome if multiple
  • Recurrence, scarring and dyspigmentation after treatment
Case reports
Treatment
Clinical images

Images hosted on other servers:

Disseminated brownish papules

Eruptive syringoma:
multiple flat papules
on thighs

Eyelid syringoma

Gross description
  • 1 - 4 mm, firm, skin colored papule with or without eruption
Gross images
Microscopic (histologic) description
  • Well circumscribed proliferation with 2 components:
    • Epithelial cells forming ductules, nests, cysts and cords
      • Cells are basaloid, cuboidal and double layered (in ductules) with an eosinophilic cuticle
      • Ducts: often round, comma or tadpole shaped (paisley pattern)
      • May have cytoplasmic clearing due to glycogen accumulation (clear cell syringoma), more common in diabetics
      • Some small cysts may have squamous lining
      • Variable luminal proteinaceous debris / keratin debris
    • Stromal fibrosis / sclerosis
  • Usually in superficial reticular dermis, rarely deep dermal extension
  • No cytologic atypia
  • Very rare mitoses
  • Reference: Calonje: McKee's Pathology of the Skin, 5th Edition, 2019
Microscopic (histologic) images

Contributed by Aadil Ahmed, M.D. and Sara C. Shalin, M.D., Ph.D.

Well circumscribed syringoma

Comma shaped ductules and nests

Basaloid proliferation

Paisley or tadpole shaped pattern


Clear cell change

Clear cell syringoma

Conventional and clear cell components

Incidental syringoma

Cytology description
Positive stains
Electron microscopy description
  • Eccrine origin
Molecular / cytogenetics description
Sample pathology report
  • Skin, eyelid, biopsy:
    • Syringoma
    • Microscopic description: Histologic sections show skin with an unremarkable epidermis. Within the superficial dermis, a circumscribed proliferation of multiple ductular structures lined by 2 layers of epithelial cells is present coursing within densely fibrotic stroma. There is minimal cytologic atypia and mitoses are not abundant.
Differential diagnosis
Board review style question #1

Which of these characteristics is typical of this well circumscribed, dermal lesion?

  1. Associated with Turner syndrome
  2. May recur after excision
  3. Often multiple 1 - 4 mm, firm, flesh colored papules
  4. Painful lesions
  5. Strongly SOX10 immunoreactive
Board review style answer #1
C. Often multiple 1 - 4 mm, firm, flesh colored papules. The image shows a syringoma. These lesions are often multiple 1 - 4 mm, firm, flesh colored papules. They are typically asymptomatic but may present with pruritus. Various cell components are immunoreactive for CEA, EMA and CK5 but not for SOX10. They have benign behavior and excision is adequate. They are associated with Ehlers-Danlos, Marfan and Down syndromes.

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Reference: Syringoma
Board review style question #2
Clear cell change seen in syringomas is due to

  1. Clearing artifact
  2. Globulin
  3. Glycogen
  4. Lipids
  5. Mucin
Board review style answer #2
C. Glycogen. The ductal cells in syringoma can infrequently exhibit clear cell change in focal areas that is due to accumulation of glycogen. Rarely, all cells are glycogen rich, termed clear cell variant and commonly associated with diabetes mellitus.

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Reference: Syringoma
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