Penis and scrotum
Neoplastic lesions of scrotum
Calcifying fibrous pseudotumor

Topic Completed: 1 May 2010

Revised: 14 February 2019

Copyright: 2002-2019,, Inc.

PubMed Search: Calcifying fibrous pseudotumor

Alcides Chaux, M.D.
Antonio L. Cubilla, M.D.
Page views in 2018: 348
Page views in 2019 to date: 412
Cite this page: Chaux A, Cubilla AL. Calcifying fibrous pseudotumor. website. Accessed September 17th, 2019.
Definition / general
  • Uncommon; young patients (mean age 16 - 19 years)
  • Extremities, trunk, scrotum (very rare), groin, neck and axilla
Clinical features
  • Tumor mass in an otherwise healthy patient, located in subcutaneous or deep soft tissue
  • Very rarely multifocal
  • Local recurrences in 30%
Case reports
  • Local excision
Gross description
  • Well circumscribed, tan-gray and solid
  • Occasionally infiltrative borders or entrapped structures
  • Some cases have myxoid changes
  • Tumor size 0.5 - 26 cm (mean 5.5 cm)
Gross images

Images hosted on other servers:

Not from scrotum

Microscopic (histologic) description
  • Spindle cells arranged in an irregular fascicular pattern
  • Abundant hyalinized collagen
  • Psammomatous, ossifying or dystrophic calcification
  • Occasionally foreign body giant cell reaction
  • Lymphoplasmacytic infiltrate
  • High microvasculature density
  • Entrapment of muscle, adipose tissue and nerve bundles is a common finding
  • Variable eosinophils, neutrophils, mast cells and germinal centers
  • No necrosis, no atypia and no mitoses
Microscopic (histologic) images

AFIP images

Microcalcifications vary in size

Adrenal gland tumor
has paucicellular fibrous
proliferation with focal

Lymphoplasmacytic inflammation is characteristic

Positive stains
Electron microscopy description
  • Consistent with immature fibroblasts
  • Abundant collagen fibrils in extracellular space
Differential diagnosis
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