Grading of bone marrow fibrosis
Grading . | Description* . |
|---|---|
| MF-0 | Scattered linear reticulin with no intersections (crossovers) corresponding to normal bone marrow |
| MF-1 | Loose network of reticulin with many intersections, especially in perivascular areas |
| MF-2 | Diffuse and dense increase in reticulin with extensive intersections, occasionally with focal bundles of collagen and/or focal osteosclerosis |
| MF-3 | Diffuse and dense increase in reticulin with extensive intersections and coarse bundles of collagen, often associated with osteosclerosis |
Grading . | Description* . |
|---|---|
| MF-0 | Scattered linear reticulin with no intersections (crossovers) corresponding to normal bone marrow |
| MF-1 | Loose network of reticulin with many intersections, especially in perivascular areas |
| MF-2 | Diffuse and dense increase in reticulin with extensive intersections, occasionally with focal bundles of collagen and/or focal osteosclerosis |
| MF-3 | Diffuse and dense increase in reticulin with extensive intersections and coarse bundles of collagen, often associated with osteosclerosis |
The quality of the reticulin stain should be assessed by detection of normal staining in vessel walls as internal control. The degree of myelofibrosis should be assessed by disregarding lymphoid nodules and vessels and disregarding fibers framing adipocytes. Areas of prominent scleredema and/or scarring should be included in the overall grading of myelofibrosis. Fiber density should be assessed in hematopoietic areas.18