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Synovitis Pathology

Synovial Lining Hyperplasia

Feature:

Number of cells that comprise the height of the synovial lining layer seen in over half the identifiable synovial surfaces  (Exclude sectioning artifact that results in “thickening” of the lining due to tangential cutting.)

Magnification: 4-5x

Grading:

  • 0: (6%) 1 cell thick
  • 1: (43%)  2-3 cells thick
  • 2: (31%) 3-4 cells thick
  • 3: (20%) > 4 cells thick

Grade 1 | Grade 2 | Grade 3

Grade 1: The condensation of cells at the 2 surfaces visible in this field ranges from 1 up to 3 cells thick, providing the lowest level of ‘hyperplasia’ discernible in a tissue section.
Grade 2: The synovial lining in this image is thicker than grade 1 but is consistently between 3 and 4 cells thick. Overlapping and bunching up can be appreciated as well.
Grade 3 Example 1: The 2 surfaces in this field show more than 4 cells, with less defined lower borders and larger cells at the surface, indicating a highly reactive lining layer.
Grade 3 Example 2: The lining layer in this field is remarkably thick due to tangential sectioning which results in the appearance of sheets of synovial lining cells instead of a discernible layer. Due to angle of sectioning, it is possible to make a layer look thicker than it is, but not thinner.

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