Penis & scrotum
Mesenchymal tumors
Leiomyoma with bizarre nuclei

Topic Completed: 1 May 2010

Minor changes: 14 February 2019

Copyright: 2002-2019,, Inc.

PubMed Search: Leiomyoma with bizarre nuclei

Alcides Chaux, M.D.
Antonio L. Cubilla, M.D.
Page views in 2019: 493
Page views in 2020 to date: 444
Cite this page: Chaux A, Cubilla AL. Leiomyoma with bizarre nuclei. website. Accessed September 21st, 2020.
Definition / general
  • Very rare
  • Also called symplastic, atypical or pleomorphic leiomyoma
  • Nuclear atypia most likely is degenerative, as in ancient schwannomas
Clinical features
  • Benign with no local recurrence or distant metastases
Case reports
Clinical images

Images hosted on other servers:

Scrotal tumor

Gross description
  • Firm, well delineated mass, tan-yellow and solid
Microscopic (histologic) description
  • Well circumscribed, nonencapsulated multilobulated tumor
  • Fascicles of spindle cells with cigar shaped nuclei, abundant eosinophilic cytoplasm
  • Varying amounts of cells with hyperchromasia, pleomorphic nuclei and macronucleoli
  • No mitotic figures, no hypercellularity, no infiltrative margins and no necrosis
Microscopic (histologic) images

Images hosted on other servers:

Pleomorphic nuclei, nuclear inclusions

Smooth muscle cells with focal atypia

Various images

Negative stains
Differential diagnosis
  • Angioleiomyoma: arises from vessel musculature, encapsulated, highly vascular and painful
  • Leiomyosarcoma: > 10 mitosis/10 HPF (although any mitotic activity in a scrotal lesion is worrisome), pleomorphism and coagulation necrosis
  • Piloleiomyoma: arises from arrectores pilorum muscle of dermis, poorly delineated and painful
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