Vulva & female urethra
Glandular tumors
Eccrine spiradenoma

Topic Completed: 1 February 2016

Revised: 8 November 2019

Copyright: 2002-2019,, Inc.

PubMed Search: Eccrine spiradenoma [title] vulva

Nicole Riddle, M.D.
Page views in 2018: 2,714
Page views in 2019 to date: 3,111
Cite this page: Riddle N. Eccrine spiradenoma. website. Accessed December 10th, 2019.
Definition / general
  • Benign adnexal tumor with eccrine differentiation, may be derived from the secretory coil
  • See also topic in Skin-nonmelanocytic tumor chapter
Essential features
  • Solitary, painful, slowly growing, pink-gray lesion, often > 1cm
  • Well circumscribed, round / oval cell nests ("blue balls") in dermis or subcutaneous tissue
  • Small basaloid cells on the outside and larger polygonal cells with vesicular nuclei and prominent nucleoli towards the center
  • Also known as spiradenoma
  • Rare in vulva
  • Commonly during reproductive age
  • Trunk > Scalp
  • Genital area rare (clitoris, labia majora)
  • May be associated with CTNNB1 or CYLD gene mutations (Brooke-Speigler syndrome)
Clinical features
  • Painful, slow growing mobile nodule. treated by excision
  • Rarely linear, zosteriform or Blaschko line type configuration
  • Malignant transformation: rapid growth, ulceration, discoloration
Prognostic factors
  • Excellent prognosis (benign lesion), unless malignant transformation
Case reports
Clinical images

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Breast skin

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Gross description
  • Pink–gray or tan nodule, usually solitary
Microscopic (histologic) description
  • Well circumscribed, round-oval cell nests ("blue balls") in dermis or subcutaneous
  • Closely packed basaloid cells in organoid arrangement – more polygonal in center
  • Delicate fibrovascular capsule
  • No epidermal connection
  • May see ductal structures or squamoid areas
  • Lymphocytes common throughout lesion
  • Dilated intervening vessels may occur, sometimes so marked as to mimic vascular tumor
  • Cystic degeneration may occur
  • Malignant transformation: highly atypical cells, infiltrating, with numerous mitoses; sarcomatous features may be seen; often residual benign spiradenoma present
Microscopic (histologic) images

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Basophillic cells

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Two tumor cell types

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Prominent, dilated vessels

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Interspersed lymphocytes

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Edematous change

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Thin, fibrous capsule

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Duct-like structures

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Cytology description
  • Small cells with scant cytoplasm, hyperchromatic nuclei, no or minimal atypia, very rare mitoses
Cytology images

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Contributed by Nicole Riddle, M.D.
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Various images

Positive stains
Differential diagnosis
  • Cylindroma: small islands of tumor cells with 'jigsaw puzzle' pattern; thick, eosinophilic, material around cell clusters
Additional references
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