Soft tissue
Fibrohistiocytic tumors
Tenosynovial giant cell tumor (giant cell tumor of tendon sheath)-general

Topic Completed: 1 June 2013

Minor changes: 6 June 2020

Copyright: 2002-2020,, Inc.

PubMed Search: Giant cell tumor of tendon sheath

Vijay Shankar, M.D.
Page views in 2020 to date: 198
Cite this page: Shankar V. Tenosynovial giant cell tumor (giant cell tumor of tendon sheath) - general. website. Accessed July 7th, 2020.
Definition / general
  • Also called fibrous histiocytoma of tendon sheath, nodular tenosynovitis, xanthogranuloma, benign synovioma
  • Ages 20s - 40s, usually women
  • Develops in synovial lining of joints, tendon sheaths and bursae
  • Usually knee (80%); also ankle, hip, shoulder or elbow joint and foot
  • Almost always monoarticular, painful swelling
  • May actually be hyperplastic / reactive, 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 below)
  • 15% erode adjacent bone by pressure
  • May be related to Tendon sheath fibroma
Clinical features
  • Malignant variant:
    • Mean 61 years, no gender preference
    • Usually extra-articular, near large joints or extremities
    • Most common location is knee joint
    • High number of mitotic figures, marked nuclear hyperchromasia, few multinucleated giant cells
Case reports
  • Excision (benign) but may recur locally
Clinical images

Images hosted on other servers:


Palmar aspect of middle phalanx of index finger

Firm, nodular, nontender thumb mass

Dome shaped nodule (Fig. 1)

Well demarcated yellowish lobulated tumor (Fig. 3)

Gross description
  • Discrete encapsulated nodule, 1 - 3 cm on tendon sheath, may be attached to synovium by a pedicle
  • Red brown to orange yellow, localized, well circumscribed, resembles small walnut; diffuse form may be larger and infiltrative
Gross images

Images hosted on other servers:

Excised giant cell tumor

Microscopic (histologic) description
  • Polymorphic infiltrate of small histiocytes, multinucleated giant cells within dense fibrous tissue with hemosiderin and foamy macrophages
  • Mitotic figures and focal hyalinized areas; tumor margins are more cellular
Microscopic (histologic) images

Images hosted on other servers:

2A: H&E with multinucleated giant cells and
mononuclear cells; B: mononuclear cells are HAM56+;
C: giant cells and some mononuclear cells are TRAP+; 3:
differentiation sequence of giant cell tumor

Giant cell (Case presentation: Fig. 2)

Low power and high power

Circumscribed lobulated nodule (Fig. 4)

Histiocytes with
abundant eosinophilic
cytoplasm (Fig. 5)

Low power view of thumb tumor

High power view of cellular zone

High power view of hypocellular zone

CD68 immunostaining of cellular zone

Ki67 immunostaining of peripheral zone

CD45 immunostaining of peripheral zone

Electron microscopy description
  • Synovial cells, fibroblasts, histiocytes, lymphocytes
Differential diagnosis
  • Epithelioid sarcoma: granulomalike formations, necrosis, invasive, epithelioid features, keratin+
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