Soft tissue
Fibroblastic / myofibroblastic
Desmoplastic fibroblastoma
Author: Komal Arora, M.D.
Last author update: 1 July 2012
Last staff update: 30 September 2021
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Desmoplastic fibroblastoma
Table of Contents
Definition / general | Epidemiology | Sites | Case reports | Treatment | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Electron microscopy description | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: Arora K. Desmoplastic fibroblastoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuecollagenousfibroma.html. Accessed April 26th, 2024.
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
- 41 year old woman with thigh mass (J Cutan Pathol 2008;35:70)
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
Microscopic (histologic) 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
Microscopic (histologic) images
AFIP images
Large, reactive
appearing spindled
fibroblasts in
fibrous matrix
Focus of low cellularity and dense collagen
More cellular area with reactive type fibroblasts
Positive stains
- Vimentin, variable alpha smooth muscle actin
Electron microscopy description
- May have fibronexus junctions-markers of myofibroblastic differentiation (Ultrastruct Pathol 2004;28:149)
Molecular / cytogenetics description
- t(2;11)(q31;q12) or 11q12 abnormalities observed rarely (Cancer Genet Cytogenet 2004;149:161, Cancer Genet 2011;204:569, Histopathology 2007;51:859, Cancer Genet Cytogenet 2009;192:73)
Differential diagnosis
- Fibromatosis: not circumscribed, more cellular, fascicular pattern, prominent vasculature (Adv Anat Pathol 1999;6:275)
Additional references
