Soft tissue
Fibroblastic / myofibroblastic tumors
Giant cell fibroblastoma

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

Revised: 19 August 2016, last major update July 2012

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

PubMed Search: Giant cell fibroblastoma [title]

Definition / General
Epidemiology
  • Usually children less than 10 years old, 2/3 male
  • Painless nodule of subcutis, usually in trunk, extremities, head and neck
  • 50% recur but recurrences are controllable, no metastases
Case Reports
Clinical Images

Images hosted on PathOut servers:

Mammogram, courtesy of Mark R. Wick, M.D.

Gross Description
  • Poorly circumscribed, gray to yellow mucoid mass that is difficult to completely excise, usually in subcutis
Micro Description
  • Dermis and subcutis contains hyperchromatic spindle or stellate shaped cells in a collagenous or myxoid matrix with scattered hyperchromatic, multinucleated, floret-like giant cells with prominent nucleoli, similar to those in pleomorphic lipomas
  • Ectatic pseudovascular spaces are lined by a discontinuous row of floret-like cells and tumor cells
  • Honeycomb or parallel pattern of infiltration
  • Also hyalinized area, perivascular lymphocytes in onionskin pattern, intralesional hemorrhage
  • Often foci of DFSP
  • No histiocyte-like cells, no mitotic figures
Micro Images

Images hosted on PathOut servers:

Breast skin, courtesy of Mark R. Wick, M.D.

Ectatic pseudovascular spaces are lined by giant cells

Stroma has giant cells and myxoid stroma



Stroma is fibrotic with
giant cells but sparse
angiectoid spaces

Multinucleated stromal giant
cells have vesicular nuclei and
prominent nucleoli, but smaller
spindle cells have indistinct nucleoli



Images hosted on other servers:

Trunk tumor

Cytology Description
  • Moderately cellular smears with mononuclear cells, usually single but occasionally in clusters
  • Most cells have no/scanty cytoplasm, bland nuclei with small nucleoli
  • Nuclear membranes often have notches, creases or folds
  • Rare multinucleated giant cells with bland oval nuclei
  • No necrosis, no mitotic figures (Diagn Cytopathol 2002;26:398, Arch Pathol Lab Med 2001;125:1091)
Cytology Images

Images hosted on other servers:

Various images

Positive Stains
Negative Stains
Electron Microscopy Description
  • Myofibroblasts or fibroblasts
Molecular / Cytogenetics Description
  • t(17,22)(q22;q13) - creates fusion of collagen type 1 alpha 1 gene and platelet derived growth factor B chain gene
  • Also supernumerary ring chromosomes derived from t(17;22)
Differential Diagnosis
Additional References