Storiform Collagenoma
David S. Cassarino, MD, PhD
Key Facts
Terminology
Sclerotic fibroma
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
Immunohistochemistry generally not necessary, but cells will stain for FXIIIA, CD34 (focally), and vimentin
Top Differential Diagnoses
Dermatofibroma
Pleomorphic fibroma
Collagenous 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
Sclerotic fibroma
Definitions
Benign, dermal-based fibroblastic proliferation with storiforming collagen
ETIOLOGY/PATHOGENESIS
Unknown
May be related to trauma
Some cases may represent regressed dermatofibromas
Some cases are genetic
Multiple lesions are associated with Cowden syndrome, consistent with a genetic influence
CLINICAL ISSUES
Epidemiology
