Soft tissue

So called fibrohistiocytic

Tenosynovial giant cell tumour, diffuse type

Last author update: 1 August 2012
Last staff update: 23 November 2021

Copyright: 2002-2022,, Inc.

PubMed Search: Giant cell tumor of tendon sheath

Vijay Shankar, M.D.
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Cite this page: Shankar V. Tenosynovial giant cell tumour, diffuse type. website. Accessed August 14th, 2022.
Definition / general
  • Extra-articular, destructive villonodular hyperplasia with synovial mononuclear cells mixed with multinucleated giant cells, foam cells, siderophages and inflammatory cells
  • Considered the soft tissue counterpart of pigmented villonodular synovitis - may represent extension of articular tumor since often occurs near a joint
  • Also called tenosynovial giant cell tumor-diffuse type
  • Called pigmented villonodular synovitis (PVNS) when occurs near a joint
  • Note: terminology of giant cell tumors is inconsistent in literature
  • Rare; less frequent than localized type
  • Usually < age 40 years, with female predominance
Clinical features
  • Develops in synovial lining of joints, tendon sheaths and bursae
  • Usually knee (80%); also ankle, hip, shoulder, elbow, foot
  • Almost always monoarticular, painful swelling
  • May actually be hyperplastic, not neoplastic (Hum Pathol 2003;34:65)
  • Occasionally invades underlying bone; may cause bone cyst formation, loss of bone and cartilage
  • Locally aggressive; often recurs, but only rarely has malignant behavior (see malignant)
Case reports
  • Excision; may recur if inadequate excision; radiation therapy for recurrences
  • See malignant for cases with malignant behavior
Gross description
  • Brown-yellow spongy tissue, firm and nodular, often 5 cm or larger
Microscopic (histologic) description
  • Diffuse expansive sheets of cells with infiltrative borders and variable cellularity; tumor margins are more cellular
  • Also hyperplastic synovium with papillary projections composed of foamy histiocytes and hemosiderin containing macrophages
  • Large clefts, pseudoglandular or alveolar spaces lined by synovial cells, osteoclast-like multinucleated (10 - 70 nuclei) giant cells, epithelioid cells
  • Abundant collagen may be present, but lymphocytes and plasma cells are sparse
  • Also giant hemosiderotic granules (2 - 3x diameter of RBC), giant siderophages (Pathologe 2005;26:96)
  • May have 5+ mitotic figures / 10 HPF, rarely chondroid metaplasia (Mod Pathol 2007;20:545)
  • Malignant if nodular and solid invasive growth plus large cells with large nuclei, prominent nucleoli, necrotic areas and atypical mitotic figures (see malignant)
Microscopic (histologic) images

Images hosted on other servers:

Shoulder tumor

Histiocytes and giant cells in dense connective tissue stroma

Iron deposits (Prussian blue stain)

Foam cells

Multiple synovial
lined clefts and
hemosiderin deposits
in the subsynovial layer

Cytology description
  • Round, spindled and multinucleated cells without atypia
  • Round cells have minimal cytoplasm and eccentric nuclei, occasional cytoplasmic hemosiderin, no mitotic figures
Positive stains
Negative stains
Electron microscopy description
Molecular / cytogenetics description
Differential diagnosis
  • Hemosiderotic synovitis: associated with hemophilia and intraarticular bleeding, no mononuclear or giant cell nodular proliferation, hemosiderin primarily in synovial lining cells
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