Myositis Ossificans - Morphology
Image Description
Microscopic Features: Higher magnification of the previous image showing the characteristic zonal pattern of myositis ossificans.
The innermost zone (right) consists of highly cellular, immature-appearing, loosely textured, fibroblastic/myofibroblastic proliferation in a vascular, collagenous background.
The intermediate zone (center of the image) shows transition from spindle cell stroma to irregularly-shaped, poorly-defined osteoid trabeculae line by plump osteoblasts.
The outermost zone (left) shows osteoid trabeculae undergoing mineralization to mature into arrays of lamellar bone.
The innermost zone (right) consists of highly cellular, immature-appearing, loosely textured, fibroblastic/myofibroblastic proliferation in a vascular, collagenous background.
The intermediate zone (center of the image) shows transition from spindle cell stroma to irregularly-shaped, poorly-defined osteoid trabeculae line by plump osteoblasts.
The outermost zone (left) shows osteoid trabeculae undergoing mineralization to mature into arrays of lamellar bone.