Home   Chapter Home   Jobs   Conferences   Fellowships   Books



Advertisement

Skin - Nonmelanocytic tumors

Other tumors of skin

Deep benign fibrous histiocytoma


Reviewers: Christopher Hale, M.D., Vijay Shankar, M.D. (see Reviewers page)
Revised: 23 October 2012, last major update August 2012
Copyright: (c) 2001-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Benign fibrous histiocytoma of subcutaneous tissue, deep soft tissue or parenchymal organs, with no dermal involvement (Am J Surg Pathol 1994;18:677, Am J Surg Pathol 1990;14:801, Stanford Medicine)
● Rare painless lesions, <1% of fibrohistiocytic tumors
● Usually adult males > 25 years (range 6-84 years)
● Usually extremities, head and neck, trunk; rarely in deep soft tissue of retroperitoneum, mediastinum or pelvis

Treatment
=========================================================================

● Excision
● May recur if incompletely excised, rare metastases (Am J Surg Pathol 2008;32:354)

Case reports
=========================================================================

● 25 year old woman with painful foot mass (Ann Dermatol 2011;23:S239)

Clinical images
=========================================================================



Nodule in arch of foot

Gross description
=========================================================================

● Well circumscribed with pseudocapsule, typically 4 cm (range 0.5 to 25 cm), variable hemorrhage

Micro description
=========================================================================

● Prominent storiform pattern of uniform spindle cells with ill defined eosinophilic cytoplasm and bland, elongated or plump vesicular nuclei with no atypia
● Often hemangiopericytoma-like vasculature
● Scattered lymphocytes, either multinucleated giant cells, osteoclastic giant cells or foam cells in 59%
● Usually less than 5 mitotic figures/10 HPF
● Stroma is myxoid or hyaline
● Borders are non-infiltrative, with no trapping of fat cells
● Necrosis or angiolymphatic invasion are rare

Micro images
=========================================================================



Circumscribed tumor with no trapped fat


Cellular tumor


Tumor with more fibrous stroma


Foam cells help distinguish from DFSP


Focal storiform pattern and cellular uniformity

   
Hemangiopericytoma-like vascular pattern

   
Various images

Positive stains
=========================================================================

● CD34 (40%), smooth muscle actin (38%)

Negative stains
=========================================================================

● Keratin, EMA, desmin, S100

Differential diagnosis
=========================================================================

Dermatofibrosarcoma protuberans: not circumscribed, usually infiltrative borders, “tight” storiform pattern, uniform cellularity, usually no foam cells, not sclerotic, strongly CD34+, Factor XIIIa weak/negative (Semin Cutan Med Surg 1999;18:91, Am J Surg Pathol 1994;18:677)
Nodular fasciitis: loose collagenous stroma, myxoid, mixed inflammatory cells, thin walled blood vessels
Solitary fibrous tumor: patternless (not storiform), alternating hypo- and hypercellular areas, prominent collagen fibers, no histiocytes, strongly CD34+

End of Skin - Nonmelanocytic tumors > Other tumors of skin > Deep benign fibrous histiocytoma


This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).