Proliferative myositis

Occurrence of proliferative myositis after COVID-19 vaccination: A case report

“…In pathology examination, PM is generally characterized with 1) infiltration of muscle with large eosinophilic giant cells and 2) proliferative fibroblasts mainly targeting the interfascicular connective tissue. In contrast to other similar disorders like myositis ossificans or nodular fasciitis, the actual muscle is not involved and largely preserved in PM [7] . After the establishment of the diagnosis, the recommended treatment strategy is no specific treatment, because PM might disappear spontaneously.…”

“…The exact etiology of PM is unknown. Nonetheless, history of recent trauma, ischemia, vasculitis, and chromosomal abnormalities have been introduced as potential etiologies [7] . None of these etiologies were the cause of PM in our case.…”

“…US is the first modality for initial investigation [7] , which might show a “scaffolding” pattern on longitudinal views and “checkerboard” pattern on transverse views [8] . Previous studies have also characterized the appearance of PM as a well-defined, lobulated, expansive intramuscular lesion [8] .…”