TABLE I

TGCT Classification and Clinical Features*

Current ClassificationPrevious NomenclatureTissue OriginClinical FeaturesEtiology
Diffuse-tenosynovial giant-cell tumor (d-TGCT)Diffuse-PVNS2, diffuse-type giant-cell tumor (Dt-GCT)4Not always clear; involves extensive regions of synovium of tendon sheath, bursae, and/or jointsPain and swelling, locally aggressive, osteochondral destruction commonNeoplastic process with overexpression of colony stimulating factor-1 (CSF-1) caused by a chromosomal translocation, which is common to both variants
Localized-tenosynovial giant-cell tumor (l-TGCT) (i = intra-articular; ii = extra-articular)Localized PVNS2, giant-cell tumor of tendon sheath (GCTTS)4Synovium of tendon sheath, bursae, or joints; often anchored to synovium at 1 point by tissue stalkPainless lump common, cortical erosions less common than diffuse variant, impingement/decreased motion due to tumor massSame as above
  • * As described by Somerhausen and van den Rijn1.