Soft tissue
Fibroblastic / myofibroblastic
Elastofibroma
Author: Komal Arora, M.D.
Last author update: 1 July 2012
Last staff update: 11 September 2023 (update in progress)
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Elastofibroma
Table of Contents
Definition / general | Epidemiology | Sites | Case reports | Treatment | Clinical images | Gross description | Gross images | 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. Elastofibroma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissueelastofibroma.html. Accessed October 2nd, 2023.
Definition / general
- Benign, poorly circumscribed pseudotumor of subscapular region, composed of collagen and coarse enlarged elastic fibers
- Reactive hyperplasia involving abnormal elastogenesis
- Also called elastofibroma dorsi
- First described in 1961 by Jarvi and Saxen (Acta Pathol Microbiol Scand 1961;51:83)
Epidemiology
- Usually age 55+ years
- Associated with hard manual labor
- Related changes found at autopsy in 13 - 17% of elderly
- More common in women
Sites
- More common on apex of scapula, usually right sided
- Occasionally in deltoid muscle, infraolecranon area, hip, thigh, stomach
- May be multiple, bilateral or familial
- May be periosteal in origin
- Slightly different amino acids from elastin
- Has collagen types I - III (type II normally restricted to articular cartilage and ocular structures)
Case reports
- 55 year old woman with subscapular soft tissue mass (Case of the Week #46)
- 69 year old man with tumor of hand (J Bone Joint Surg Br 1987;69:468)
- 69 year old woman with bilateral subscapular tumors and tumor surrounding a stomach ulcer (Am J Surg Pathol 1985;9:233)
- 78 year old man with multiple subcutaneous nodules (J Am Acad Dermatol 2004;50:126)
Treatment
- Excise if symptomatic, does not recur
Clinical images
Contributed by Mark R. Wick, M.D.
MRI
Images hosted on other servers:
Shoulder based tumors
Typical location (arrow)
Gross description
- Ill defined, rubbery, gray-white fibrous tissue mixed with yellow streaks of elastin
- Up to 15 cm
Gross images
AFIP images
Fibrocollagenous areas blend with fat
Images hosted on other servers:
Poorly defined fibroelastic tumor entrapping fat
Gray-white fibrous tissue mixed with fat
Microscopic (histologic) description
- Collagen bundles alternate with large, thick eosinophilic elastic cylinders with a dense central core, elastic fibers may be fragmented into linear globules (beads on a string)
- Often has irregular interdigitation into adipose tissue
Microscopic (histologic) images
Contributed by David Cohen, M.D. and Victor Lee, M.D. (Case #46), Mark R. Wick, M.D. and AFIP
Paucicellular fibrous tissue mixed with fat
Densely eosinophilic elastin bands
Elastin bands have serrated edges
Dorsi
Verhoeff elastin stain
Elastic stain
Orcein (elastin) stain
Images hosted on other servers:
Mature adipose tissue
Branched and
unbranched
coarse elastin
fibers
H&E and elastic stain
Verhoeff elastin stain highlights elastin fibers and the bead-like arrangement of the elastin globules
Cytology description
- Hypocellular smear with diagnostic aggregates of globules within a collagenous matrix (Diagn Cytopathol 2012;40:E99, Acta Cytol 2007;51:497, Anticancer Res 2002;22:3561)
- Altered elastic fibers have green-yellow autofluorescence with ultraviolet light (Diagn Cytopathol 2002;26:310)
Positive stains
- Vimentin, elastic stains (fibers have dense core and irregular margins), CD34 in spindle cells (Virchows Arch 2006;448:195)
Negative stains
Electron microscopy description
- Cylinders composed of immature amorphous elastic tissue, central core contains mature fibers, removed by elastase digestion (J Electron Microsc (Tokyo) 2006;55:89, Med Mol Morphol 2008;41:179)
Molecular / cytogenetics description
- Xq12-q22 or #19 gains in 30% (Int J Mol Med 2002;10:277)
Differential diagnosis
- Desmoid fibromatosis:
- More cellular
- Infiltrates skeletal muscle
- No elastic fibers
- Fibrolipoma:
- No elastic fibers
- Nuchal fibroma:
- Younger than 55 years
- Between scapula and vertebrae
- Dense collagen but no elastic fibers
