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diffuse type of giant cell tumor of tendon sheath

ICD-0 9251/0

Wednesday 18 February 2004

pigmented villonodular synovitis (PVNS); pigmented villonodular tenosynovitis; tenosynovial giant cell tumor, diffuse type; diffuse type of giant-cell tumor of the tendon sheath (GCTTS); tenosynovial giant cell tumor-diffuse type; formerly called pigmented villonodular synovitis (PVNS) when occurs near a joint; giant cell tumor of tendon sheath, diffuse type


Definition: Diffuse giant cell tumor of tendon sheath (or pigmented villonodular synovitis) is an extra-articular, destructive villonodular hyperplasia with synovial mononuclear cells mixed with multinucleated giant cells, foam cells, siderophages and inflammatory cells.

Digital slides

- JRC:6551 : Pigmented villonodular synovitis.




In these less common diffuse form of giant cell tumor of tendon sheath, the knee and ankle joints are commonly affected with a fond papillary synovitis and a histology similar to the nodular type.

The "diffuse form of giant cell tumor of tendon sheath" is not encapsulated but, instead, grows around the joint cavity with extension to soft tissue.

These lesions are much more locally aggressive, eroding joints and recurring in nearly half of the cases.

The diffuse form of giant cell tumor of tendon is considered the soft tissue counterpart of "pigmented villonodular synovitis".

It may represent extension of articular tumor since often occurs near a joint

Clinical synopsis

- Rare; less frequent than localized type
- Usually @<@ age 40 years
- Develops in synovial lining of joints, tendon sheaths and bursae
- Usually knee (80%); also ankle, hip, shoulder or elbow joint
- Almost always monoarticular
- Occasionally invades underlying bone; may cause bone cyst formation, loss of bone and cartilage

Pathological synopsis

- Brown-yellow spongy tissue, firm and nodular, often 5 cm or larger
- arise in the vicinity of large joints of the lower extremity
- proliferation of polygonal mononuclear cells
- osteoclastlike giant cells
- foam cells
- siderophages
- poorly delineated
- infiltrative pattern into the neighboring soft tissues


Its anatomic distribution parallels that of PVNS, with lesions most commonly found around the knee, followed by the ankle and foot; however, the diffuse form occasionally affects the hand.


Typically, these lesions, like those of PVNS, occur in young patients; 50% of cases are diagnosed in patients younger than 40 years.


The diffuse form is often locally aggressive, and multiple recurrences after excision are common.


Because of the similarities in age, tumor locations, clinical presentations, and symptoms for patients with PVNS and patients with the diffuse form of giant cell tumors of the tendon sheath, the diffuse form probably represents an extra-articular extension of a primary intra-articular PVNS process.

Findings from flow cytometric DNA analysis suggest that PVNS and giant cell tumors of the tendon sheath are histopathologically similar but clinically distinct lesions.

When the origin of these poorly confined soft-tissue masses is uncertain, Enzinger and Weiss classify these tumors as the diffuse type of giant cell tumors of the tendon sheath, whether or not they involve the adjacent joint.

Intra-articular forms

- Diffuse expansive sheets of cells with infiltrative borders and variable cellularity
- 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 Path 2007;20:545)
- Malignant if nodular and solid invasive growth plus large cells with large nuclei, prominent nucleoli, necrotic areas and atypical mitotic figures


- Round, spindled and multinucleated cells without atypia
- Round cells have minimal cytoplasm and eccentric nuclei
- occasional cytoplasmic hemosiderin
- no mitotic figures


- strong expression of :

  • vimentin,
  • neuron-specific enolase (NSE),
  • A1-antitrypsin (A1AT),
  • CD68 in both mono- and multinucleated tumor cells.


- mononuclear cells : diverse morphology, features of histiocytelike and fibroblastlike cells, with the former being more numerous.
- scarce neurosecretorylike granules, made up of electrondense membrane-bound material, in the cytoplasm of the mononuclear cells.


- t(2;3) (12028654)
- der(8) t(8;12) (12028654)

Differential diagnosis

- detritic synovitis
- alpha-mannosidase deficiency


- Locally aggressive;
- often recurs
- only rarely has malignant behavior

Treatment and prognosis

- Excision, may recur if inadequate excision;
- radiation therapy for recurrences


- eMedicine

See also

- giant cell tumor of the tendon sheath (GCTTS)
- malignant forms of diffuse type of GCTTS (HP.)


- Ferrer J, Namiq A, Carda C, López-Ginés C, Tawfik O, Llombart-Bosch A. Diffuse type of giant-cell tumor of tendon sheath: an ultrastructural study of two cases with cytogenetic support. Ultrastruct Pathol. 2002 Jan-Feb;26(1):15-21. PMID: 12028654

- Diffuse Type of Giant-Cell Tumor of Tendon Sheath: An Ultrastructural Study of Two Cases With Cytogenetic Support. Ferrer J; Namiq A; Carda C; López-Ginés C; Tawfik O; Llombart-Bosch A. Ultrastructural Pathology, Volume 26, Number 1, 1 January 2002 , pp. 15-21(7)