Penis and scrotum
Neoplastic lesions of scrotum
Calcifying fibrous pseudotumor

Authors: Antonio Cubilla, M.D., Alcides Chaux, M.D. (see Authors page)

Revised: 10 April 2018, last major update May 2010

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Calcifying fibrous pseudotumor

Cite this page: Cubilla, A., Chaux, A. Calcifying fibrous pseudotumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/penscrotumcalcifyingfibrous.html. Accessed July 17th, 2018.
Definition / general
Epidemiology
  • Uncommon; young patients (mean age 16 - 19 years)
Sites
  • 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
Treatment
  • 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

Images hosted on PathOut server:

Microcalcifications vary in size

Adrenal gland tumor
has paucicellular fibrous
proliferation with focal
microcalcifications

Lymphoplasmacytic inflammation is characteristic

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