An evidence-based aetiology study of synovial cyst of cruciate knee ligament: a real or pseudo-cyst

Primary tabs

An evidence-based aetiology study of synovial cyst of cruciate knee ligament: a real or pseudo-cyst
Key Take-Away: 

The cystic lesions of the knee can frequently be detected using magnetic resonance trials. However, pathogenesis as per histo- and cytopathological examination is not familiar and attempted to assess using the following analysis.

Synovial cyst of knee cruciate ligament (SCKCL) is an exceptional condition but when occur causes severe knee pain. The aetiology of SCKCL is also not well-known. The study intended to evaluate the SCKCL pathogenesis by cyto- and histopathological analysis.


A total of ten patients went through arthroscopy including five patients with a past knee injury. For cyst wall tissue sections, Hematoxylin & eosin staining and for cyst fluid smear, Papanicolaou staining was used. Prussian blue staining was applied to both the fluid smear and wall section. The probable involvement of several cell types in the SCKCL development was assessed using immunohistochemical staining for vascular endothelial cells (CD31), monocytes (CD68), hematogenous stem cells (CD117), mesothelial cells (MC), and epithelial cells (CK).


There is no erythrocyte present in the fluid. Although, all patients cyst wall and fluid present with Prussian blue stained hemosiderin particles, proposing past haemorrhage. Plasmocytes and lymphocytes were present in abundance in both cyst wall and fluid. Moreover, the Abundant CD68(+) monocytes infiltrated the cyst lining; whereas the MC(+) mesothelial cells among the four samples were present in inadequate amount. The cyst submucosa was also abundant with CD68(+) monocytes. The proliferated capillaries are known to be stained with CD31. Eight specimens observed with CD117-positive hematogenous stem cells sporadically.


As per the findings, SCKCL is not a mature synovial cyst but is an inflammatory pseudo-cyst, originated from past minor intra-ligament chronic inflammation and haemorrhage.


International Orthopaedics

Link to the source:

Original title of article:

An evidence-based etiology study of synovial cyst of knee cruciate ligament: a real or pseudo-cyst.


Jun Xiao et al.

Exploratory, Knee Pain, Knee Ligament
Log in or register to post comments