Soft tissue
Fibroblastic / myofibroblastic tumors
Desmoplastic fibroblastoma

Author: Komal Arora, M.D. (see Authors page)

Revised: 15 August 2016, last major update July 2012

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Desmoplastic fibroblastoma

Definition / General
  • Fibroblastic lesion centered in subcutaneous tissue with reactive fibroblasts, low cellularity and abundant collagen (Hum Pathol 1998;29:676)
  • Also called collagenous fibroma
Epidemiology
  • Rare benign lesion of adult men (70% between ages 40 and 69 years)
Sites
  • Usually upper extremities, back, feet
Case Reports
Treatment
  • Conservative excision, does not recur or metastasize
Gross Description
  • Usually 1 - 4 cm, well circumscribed, may be lobulated, has firm and homogeneous gray cut surface resembling cartilage
Gross Images

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Well circumscribed tumor

Micro Description
  • Paucicellular, bland spindled (stellate) and reactive appearing fibroblasts and myofibroblasts separated by abundant collagen with variable myxoid stroma
  • Fibroblasts have amphophilic cytoplasm, vesicular nuclei and distinct nucleoli
  • 70% of cases involve subcutis, 25% extend into skeletal muscle
Micro Images

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Large, reactive appearing spindled fibroblasts in fibrous matrix

Focus of low cellularity and dense collagen

More cellular area with reactive type fibroblasts

Positive Stains
Negative Stains
Electron Microscopy Description
Molecular / Cytogenetics Description
Differential Diagnosis