Soft tissue
Fibrohistiocytic tumors
Plexiform fibrohistiocytic tumor

Author: Vijay Shankar, M.D. (see Authors page)

Revised: 15 September 2016, last major update August 2012

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: Plexiform fibrohistiocytic tumor [title] soft tissue

Cite this page: Plexiform fibrohistiocytic tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/softtissueplexiformfh.html. Accessed December 6th, 2016.
Definition / General
  • Dermal or subcutaneous, plexiform or multinodular proliferation of fibrohistiocytic cells and osteoclast-like giant cells with chronic inflammatory infiltrate
Terminology
Epidemiology
  • Usually children and young adults, 80% female
Clinical Features
Case Reports
Treatment
Gross Description
  • Multinodular, poorly circumscribed, firm, dermal or subcutaneous, 3 cm or less
Micro Description
  • Deep dermal or subcutaneous tumor with ray like extension into skeletal muscle or adipose tissue
  • Overlying epidermis and dermis are usually normal
  • Plexiform or multinodular proliferation of fibrohistiocytic cells with minimal atypia plus osteoclast-like giant cells and chronic inflammatory infiltrate
  • Nodules or clusters are interconnected in characteristic plexiform arrangement
  • Prominent dilated vessels; more sclerotic than MFH
  • Often hemorrhage and hemosiderin
  • Vascular invasion in 10 - 20%
  • Usually 0 - 2 MF / 10 HPF, no necrosis
  • Subtypes are fibrohistiocytic (histiocyte-like cells and giant cells), fibroblastic (fibroblast-like cells) and mixed
Micro Images

Images hosted on PathOut servers:

Subcutaneous proliferation of bland fibrous tissue which radiates outward from center of lesion

Tumors have nodules of histiocyte-like cells
and giant cells, fibrous tissue and hemorrhage



Histiocyte-like cells, pale staining cytoplasm; giant cells present

Nodules may be composed of cells w/ elongated nuclei

Tumor with nodules and fibrous tissue

Fibrous tissue may resemble desmoid fibromatosis



Courtesy of Mark R. Wick, M.D.





Case of Week #180



Images hosted on other servers:

Various images

12 year old girl with upper arm lesion



Cytology Description
  • Plump fibroblastic cells and histiocyte-like cells within a finely granular myxoid background
  • Also osteoclast-like giant cells (Acta Cytol 1999;43:867)
Positive Stains
Negative Stains
Electron Microscopy Description
  • Resembles myofibroblasts, fibroblasts and undifferentiated cells
Differential Diagnosis