Skin nonmelanocytic tumor
Fibrous, fibrohistiocytic and myofibroblastic neoplasms
Collagenous fibroma


Topic Completed: 1 April 2017

Revised: 18 April 2019

Copyright: 2003-2019, PathologyOutlines.com, Inc.

PubMed Search: Collagenous fibroma
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Cite this page: Elwood HR. Collagenous fibroma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/skintumornonmelanocyticcollagenousfibroma.html. Accessed April 24th, 2019.
Definition / general
  • Also called desmoplastic fibroblastoma
  • Benign soft tissue tumor that usually occurs in the subcutis or skeletal muscle, rarely dermal involvement
  • Typically arises in 5th or 6th decade of life, slowly growing mass, 4 cm or less in size
  • Arise more commonly in men
  • Most common location is upper extremity
Case reports
Microscopic (histologic) description
  • Well circumscribed hypocellular lesion
  • Bland stellate and spindled fibroblasts with prominent collagenous to myxoid matrix
  • No necrosis and minimal or absent mitoses
  • Can have scattered blood vessels, sometimes with perivascular hyalinization
Microscopic (histologic) images

Images hosted on PathOut server:
Missing Image

Contributed by Hillary Elwood, M.D.

Immunohistochemistry
Differential diagnosis
  • Neurofibroma: S100+; neural cells in myxoid stroma
  • Fibromatosis: much more cellular, often fascicular growth pattern
  • Elastofibroma: typically on shoulder, has prominent wavy elastic fibers
Board review question #1
Which of the following is TRUE of collagenous fibroma:

A. S100+
B. Usually arises in the subcutis
C. Hypercellular, infiltrative soft tissue tumor
D. Most commonly occurs in children
E. Metastasis common
Board review answer #1
B. Collagenous fibroma is a benign soft tissue tumor that usually arises in the subcutis, with dermal involvement less common. The lesion is hypocellular, well circumscribed, and most commonly occurs in adults. S100 immunostain is negative within lesional cells.
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