Sclerotic Fibroma
David Cassarino, MD, PhD
Key Facts
Terminology
Storiform collagenoma
Benign, dermal-based fibroblastic proliferation
Microscopic Pathology
Composed of thickened, hyalinized-appearing collagen bundles in storiform/whorled pattern
Occasional cases may show large, bizarre-appearing cells (“pleomorphic sclerotic fibroma”), similar to pleomorphic fibroma
Ancillary Tests
IHC generally not necessary, but cells should stain for FXIIIA, CD34 (focally), and vimentin
Top Differential Diagnoses
Dermatofibroma
Pleomorphic fibroma
Collagenous fibroma
Acral fibrokeratoma (subungual and periungual fibroma)
 Scanning magnification view shows a dermal-based nodular fibroblastic proliferation with storiforming of collagen. |
 Higher power magnification shows bland fibroblasts  and scattered inflammatory cells  in a dense fibrous stroma. |
TERMINOLOGY
Synonyms
Storiform collagenoma
Pleomorphic sclerotic fibroma
Definitions
Benign, dermal-based fibroblastic proliferation with storiforming bundles of collagen
ETIOLOGY/PATHOGENESIS
Unknown
May be related to trauma
Some cases may represent regressed dermatofibromas
Genetic Syndrome
Multiple lesions are associated with Cowden syndrome, consistent with genetic influence
