Soft tissue
Fibrohistiocytic tumors
Malignant fibrous histiocytoma of soft tissue - giant cell type

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

Revised: 16 September 2016, last major update August 2012

Copyright: (c) 2002-2016,, Inc.

PubMed Search: Malignant fibrous histiocytoma of soft tissue - giant cell type

Cite this page: Malignant fibrous histiocytoma of soft tissue - giant cell type. website. Accessed October 21st, 2016.
Definition / General
  • Diagnosis of exclusion - an undifferentiated pleomorphic sarcoma with prominent osteoclast-like giant cells
  • Also called malignant giant cell tumor of soft parts, malignant osteoclastoma, giant cell sarcoma
  • 3 - 15% of malignant fibrous histiocytomas
  • Number of cases is declining as specific sarcoma types are identified
  • Rare in children
Clinical Features
  • Extremities and trunk
  • Osteoclast-like cells have functional features of osteoclasts (J Pathol 1989;159:53)
Case Reports
Gross Description
  • Hemorrhagic and necrotic
Micro Description
  • Resembles pleomorphic malignant fibrous histiocytoma, with addition of evenly dispersed osteoclast-like giant cells with 20 - 100 uniform nuclei that are small and round / oval, accompanied by smaller stromal cells with similar nuclei
  • 2 - 3 MF / 10 HPF
  • May have angiolymphatic invasion
  • Rarely small foci of neoplastic bone or cartilage (some designate these tumors as osteosarcoma or chondrosarcoma)
  • No xanthoma cells or siderophages, no necrosis
Micro Images

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Osteoclast-like giant cells with uniform nuclei in a pleomorphic MFH

Tumor cells may form neoplastic bone and osteoid

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Similar lesion in prostate

Cytology Description
  • Hypercellular smear with cohesive, branching clusters of spindle cells with ovoid, focally hyperchromatic nuclei and inconspicuous nucleoli
  • Also interspersed osteoclast-like giant cells, some associated with clusters of spindle cells
  • Hemorrhagic background with cellular debris and occasional spindle cells and lymphocytes (Acta Cytol 2003;47:673)
Cytology Images

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Multinucleated osteoclastic-type giant cells

Positive Stains
Differential Diagnosis