Bone & joints
Other chondrogenic tumors
Synovial & tenosynovial chondromatosis


Topic Completed: 1 June 2013

Minor changes: 31 July 2020

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PubMed Search: Synovial chondromatosis [title] joints "loattrfree full text"[sb]"

Vijay Shankar, M.D.
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Cite this page: Shankar V. Synovial & tenosynovial chondromatosis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/jointssynovialosteochondromatosis.html. Accessed September 30th, 2020.
Definition / general
    Synovial chondromatosis:
    • Also called synovial chondrometaplasia, synovial osteochondromatosis
    • Mean age 41 years, range 17 - 64 years, 2/3 male (Hum Pathol 1998;29:683)
    • Primary disease is uncommon, unknown etiology, aggressive (Hum Pathol 1979;10:439)
    • Usually monoarticular, can be bilateral rarely (JCDR 2012;6:475), affecting knee, hip, elbow and communicating bursae; may affect adjacent soft tissue
    • Aggravated by infection and trauma
    • May be extra-articular (tenosynovial chondromatosis)

    Tenosynovial chondromatosis:
  • Multinodular cartilaginous proliferation that arises from tenosynovial membranes due to synovial metaplasia
  • Also called tenosynovial or bursal chondromatosis
  • M > F; ages 20 - 86 years (mean and median age are 46 years)
  • Fingers (50%), feet (20%)
  • Also wrists, ankles, palm, knee, forearm
Secondary disease
  • Associated with degenerative joint disease - growth of fragments of articular cartilage
  • Initially intrasynovial disease without loose bodies; then intrasynovial proliferation and free loose bodies, then multiple free osteochondral bodies without intrasynovial disease
  • No atypia
Radiology description
  • Xray: usually calcific densities within joint; may be negative or show diffuse joint swelling
Case reports
Treatment
  • Excision but frequently recurs; 5% become malignant
Clinical images

Images hosted on other servers:

Smooth white nodule

Showing extent of disease

Dorsal first web space

Multiple rice bodies within synovial sheath

Gross description
  • Synovial: numerous round osteocartilaginous nodules cover a thickened synovial surface or float freely within joint space
  • Tenosynovial: bluish white subsynovial nodules, mm to cm in size, which conglomerate into lobulated mass attached to synovial membranes
Microscopic (histologic) description
  • Synovial: cartilage cells with variable atypia or binucleated forms within synovium; clusters of chondrocytes are often arranged in lobules; no underlying arthritis
  • Tenosynovial:
    • Multinodular cartilaginous proliferation involving tenosynovium or subsynovial connective tissue
    • Cartilaginous matrix more intensely basophilic than chondroma of soft parts
    • Often minute cartilaginous nodules
    • May have mild or moderate atypia
    • Occasionally prominent mineralization
    • Rarely crystalline deposits mimic tophi (APMIS 2004;112:624)
    • Rarely malignant transformation, which resembles synovial chondrosarcoma
Microscopic (histologic) images

Images hosted on other servers:

Metaplastic cartilage in synovium

Clusters of chondrocytes

Resembles Grade 1 chondrosarcoma

Nodule of cartilage


Loose bodies

Subsynovial cartilaginous nodule

Moderate atypia of chondrocytes

Osteochondral loose body

Cartilaginous tissue enclosed by synovial tissue

Nodule surrounded by tenosynovial membrane

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Differential diagnosis
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