Penis & scrotum
Mesenchymal tumors

Topic Completed: 1 May 2010

Minor changes: 20 August 2020

Copyright: 2002-2020,, Inc.

PubMed Search: Leiomyoma penis scrotum

Alcides Chaux, M.D.
Antonio L. Cubilla, M.D.
Page views in 2019: 539
Page views in 2020 to date: 512
Cite this page: Chaux A, Cubilla AL. Leiomyoma. website. Accessed September 28th, 2020.
Definition / general
  • Benign smooth muscle tumor resembling counterparts elsewhere but very rare in penis and scrotum
  • ICD-O: 8890 / 0
  • Classified as leiomyoma cutis (originates in skin) or dartoic leiomyoma (originates in tunica dartos)
  • Scrotal leiomyoma cutis can be further subclassified as pilar leiomyoma (originates in adnexal smooth muscle) or angioleiomyoma (originates in vascular smooth muscle)
Clinical features
  • May clinically resemble a cyst
  • Small, firm to hard, slow growing, rubbery painless mass in adults
  • Rarely polypoid or ulcerated
  • Epithelioid features, myxoid change and hyalinization are much less common than in vulvar lesions (Histopathology 1991;18:523)
Case reports
  • Conservative; local excision
Gross description
  • Tumor size 0.2 - 3.0 cm
Gross images

Images hosted on other servers:

Tan-gray cut surface

Microscopic (histologic) description
  • Circumscribed, nonencapsulated proliferation of spindle shaped cells with smooth muscle features arranged in fascicles
  • Smooth muscle fascicles separated by variably collagenized stroma
  • Bizarre, atypical and symplastic changes in some cases (see leiomyoma with bizarre nuclei)
  • Rarely myxoid changes and lymphoid aggregates
  • No necrosis, no / rare mitoses
  • Overlying skin is without epithelial alterations
Microscopic (histologic) images

AFIP images

Leiomyoma of dartos has smooth muscle bundles separated by collagenous stroma

Images hosted on other servers:

Bundles and fascicles of smooth muscle cells with eosinophilic fibrillar cytoplasm and elongated nuclei with blunted ends

Well circumscribed tumor

Interlacing bundles

Positive stains
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