Skin nonmelanocytic tumor
Fibrous, fibrohistiocytic and myofibroblastic neoplasms
Fibrous histiocytoma-aneursymal

Topic Completed: 1 August 2019

Minor changes: 21 July 2020

Copyright: 2002-2018,, Inc.

PubMed Search: Aneurysmal fibrous histiocytoma

Vijay Shankar, M.D.
Page views in 2019: 3,219
Page views in 2020 to date: 2,127
Cite this page: Shankar V. Fibrous histiocytoma-aneursymal. website. Accessed September 29th, 2020.
Definition / general
  • Rare variant with dermal spindle cells and lakes of blood, but no endothelium
  • 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
Case reports
  • 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
Negative stains
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
Differential diagnosis
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