Fibrous histiocytoma-aneursymal

Skin nonmelanocytic tumor

Fibrous, fibrohistiocytic and myofibroblastic neoplasms

Author: Vijay Shankar, M.D.

Topic Completed: 1 August 2019

Minor changes: 21 July 2020

Copyright: 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Aneurysmal fibrous histiocytoma

Page views in 2019: 3,219

Page views in 2020 to date: 2,127

Table of Contents

Cite this page: Shankar V. Fibrous histiocytoma-aneursymal. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/softtissuefhaneurysmal.html. Accessed September 29th, 2020.

Definition / general

Rare variant with dermal spindle cells and lakes of blood, but no endothelium

Terminology

First described in 1981 (Cancer 1981;47:2053)
Early lesion also called hemosiderin variant of fibrous histiocytoma
Similar to sclerosing hemangioma variant of fibrous histiocytoma, which has more prominent capillaries, but differs from lung lesion called sclerosing hemangioma

Clinical features

Usually extremities or trunk; often pigmented, rapid growth and pain (J Clin Pathol 1996;49:313)
May have history of trauma (J Korean Med Sci 1989;4:159)

Case reports

10 year old girl with leukemia (Pediatr Dermatol 2006;23:591)
38 year old man with abdominal lesion called hemosiderotic variant (Dermatology 2007;214:82)
48 year old woman with recurrent tumor (J Clin Pathol 2004;57:312)

Treatment

Excision
Tends to recur if there is incomplete excision
Rarely metastasizes

Clinical images

Images hosted on other servers:

Exophytic lesion with
slight scaling; irregular
coloration mimics melanoma

Grayish brown atrophic shiny patch

Gross description

Blue, black or dark red cystic nodule
Size varies from 0.5 to 4 cm
Rarely presents as atrophic patch

Microscopic (histologic) description

Storiform pattern of fibrohistiocytic cells (as in classic fibrous histiocytoma), but many cells are filled with hemosiderin
Also large cystic spaces filled with blood, but without an endothelial lining
Bizarre cells often present
May have hemangiopericytoma-like pattern of cysts
Periphery may have hyalinized collagen bundles surrounded by tumor cells (Histopathology 1995;26:323)
Usually epidermal hyperplasia
May have up to 10 MF / 10 HPF
Dermoscopy description: Multicomponent pattern with central blue / red homogeneous area, white structures, peripheral delicate pigment network and vascular structures (Br J Dermatol 2006;154:244); this pattern also present in some melanomas

Microscopic (histologic) images

Images hosted on PathOut servers:

Non-endothelial lined clefts or lakes containing blood

Large amounts of hemosiderin

Hemosiderin with marked sclerosis

Images hosted on other servers:

Various images

Large irregularly shaped cysts resembling HPC

Hemangiopericytoma-like pattern of cysts

Positive stains

Vimentin, Factor XIIIa (in areas without hemosiderin, J Dermatol 2002;29:744)
Variable NKI-C3 (60%), smooth muscle actin (45%)

Negative stains

CD31, CD34 (confirms that cysts do not contain endothelium), Factor VIIIa, CD68
Actin, desmin, cytokeratin, Ki67

Electron microscopy description

Hemosiderin containing histiocyte-like cells, fibroblast-like cells and intermediate cells
No prominent proliferation of endothelial cells (Am J Dermatopathol 1995;17:179)

Molecular / cytogenetics description

Single case report of recurrent tumor with t(12;19) (Cancer Genet Cytogenet 2006;164:155)

Differential diagnosis

Angiomatoid fibrous histiocytoma: thick pseudocapsule, marked chronic inflammatory infiltrate and cystic areas of hemorrhage
Angiosarcoma: lined by endothelial cells, variable atypia (APMIS 2006;114:744)
Kaposi’s sarcoma: endothelial lined vessels are present (CD31+, CD34+), KSHV / HHV8+
Spindle cell hemangioendothelioma: thick walled muscular blood vessels, organizing thrombi