Malignant pigmented villonodular synovitis in the knee - report of a case with rapid clinical progression

Open Orthop J. 2011 Jan 7;5:13-6. doi: 10.2174/1874325001105010013.


Malignant pigmented villonodular synovitis (PVNS) (or malignant giant cell tumor of tendon sheath (GCTTS) is an extremely rare condition defined as a malignant lesion occurring with concomitant or previously documented PVNS at the same site. To date, only less than 20 cases have been reported in English literatures. We report a case of malignant PVNS in the knee in a 56-year-old woman with unpredictable rapid progression. This case raised a caution that when atypical components in specimens of recurrent benign PVNS are detected, even if low-grade or tiny, both pathologists and surgeons should consider the risk of malignant PVNS, which could display aggressive clinical progression.

Keywords: Soft tissue tumor; malignant giant cell tumor of tendon sheath.; malignant pigmented villonodular synovitis.