Table of Contents
Definition / general | Epidemiology | Case reports | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Electron microscopy description | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: Arora K. Giant cell fibroblastoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuegiantcellfibro.html. Accessed May 29th, 2023.
Definition / general
- Rare childhood fibroblastic tumor of intermediate malignancy with floret-like giant cells and ectatic pseudovascular spaces lined by stromal cells and giant cells
- Part of WHO classification for skin tumors, not soft tissue tumors
- Appears to evolve into DFSP by genomic gains of COL1A1-PDGFB (Genes Chromosomes Cancer 2008;47:260)
- Considered the juvenile form of DFSP, as both have the same translocation (Am J Surg Pathol 2003;27:27, Arch Pathol Lab Med 1996;120:1052, Ann Diagn Pathol 2007;11:81)
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
- 3 year old boy with giant cell fibroblastoma (Pathol Oncol Res 2003;9:249)
- 28 year old woman with giant cell fibroblastoma of the vulva at the site of a previous fibroepithelial stromal polyp (J Low Genit Tract Dis 2007;11:112)
Gross description
- Poorly circumscribed, gray to yellow mucoid mass that is difficult to completely excise, usually in subcutis
Microscopic (histologic) 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
Microscopic (histologic) images
AFIP images
Contributed by Mark R. Wick, M.D.
Images hosted on other servers:
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)
Positive stains
- Vimentin, CD34, CD99 (40%, J Cutan Pathol 2008;35:647)
- Variable actin
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
- Angiosarcoma: older adults in head and neck, vascular tumor, cells have enlarged atypical nuclei, mitotic figures present
- Hemangioma: vascular tumor, no giant cells, CD31+
- Neurofibroma with ancient change: no ectatic vascular spaces, S100+
- Pleomorphic liposarcoma: pleomorphic cells are similar, but remaining lesion has lipoblasts and lacks collagenous matrix
Additional references