Skin nonmelanocytic tumor
Fibrous, fibrohistiocytic and myofibroblastic neoplasms
Fibrous histiocytoma-epithelioid
Author: Vijay Shankar, M.D.
Topic Completed: 1 August 2012
Minor changes: 1 October 2020
Copyright: 2002-2020, PathologyOutlines.com, Inc.
PubMed Search: Epithelioid fibrous histiocytoma
Table of Contents
Definition / general | Epidemiology | Pathophysiology | Clinical features | Case reports | Treatment | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Differential diagnosisCite this page: Shankar V. Fibrous histiocytoma-epithelioid. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuefhepithelioid.html. Accessed October 21st, 2020.
Definition / general
- Variant with 50% or more of tumor cells having epithelioid morphology
Epidemiology
- Mean / median age 40 - 42 years (Br J Dermatol 1989;120:185)
- No gender preference
Pathophysiology
- May arise from dermal microvascular unit (J Cutan Pathol 2003;30:415)
Clinical features
- Uncommon, usually presents as small (0.5 to 2 cm), solitary, very rarely multiple, skin colored elevated nodules
- Usually seen on trunk and extremities, rarely in head and neck regions
Case reports
- 20 year old man with multiple lesions (Am J Dermatopathol 2008;30:373)
- 60 year old man with scalp lesion (Case of the Week #116)
- Underlying a damaged artery (J Dermatol 2005;32:721)
Treatment
- Excision, only rarely recurs (Histopathology 1994;24:123)
Microscopic (histologic) description
- Often exophytic with epidermal collarette
- Circumscribed with uniform, medium to large angulated epithelioid cells (50%+ of tumor cells) that are often perivascular
- Many binucleated cells are often seen
- May be cellular (Am J Surg Pathol 1994;18:583)
- Periphery shows typical features of dermatofibroma
- Minimal inflammation, no prominent giant cells
Microscopic (histologic) images
AFIP images and Case #116
Histiocyte-like cells with abundant cytoplasm, no / rare spindle cells
Epithelioid cells in hyalinized stroma
60 year old man with scalp lesion
60 year old man with scalp lesion
Vimentin+
Factor XIIIa+
CD68-
Keratin-
Melan A-
Images hosted on other servers:
Epithelioid cells with vesicular nuclei
Positive stains
Differential diagnosis
- Epithelioid sarcoma: deep seated, granuloma-type clusters with necrosis, more atypia, keratin+, CD163-
- Granuloma: epithelioid histiocytes in well formed clusters, surrounded by lymphocytes
- Histiocytic sarcoma: marked atypia and mitotic activity
- Melanoma: tight clustering of atypical cells, S100+, HMB45+
- Rosai-Dorfman disease: multiple skin lesions and adenopathy, histiocytes are S100+ and pleomorphic with emperipolesis, also prominent B cells and plasma cells
- Solitary epithelioid histiocytoma: dense eosinophilic and glassy cytoplasm, often with spiked cytoplasmic extensions, variable nuclear grooves and multinucleated cells, frequent lymphocytes and neutrophils, CD68+, CD163+ (Am J Surg Pathol 2006;30:521)
- Spitz nevus: nevoid type clusters in periphery with spindle cell component, S100+
