The differential considerations of proliferative myositis are broad and contain common entities such as trauma and myositis ossificans, but also more rare diagnoses including inflammatory myopathies and malignancy.
In one of the earliest and largest case series, proliferative myositis on gross pathology was described as a poorly marginated white to grey "induration" most prominent between the muscle bundles, leading to a trabeculated pattern.
The imaging features of proliferative myositis on various modalities are typically that of a nonspecific intramuscular inflammatory process.
1, 5) The differential diagnosis includes benign muscle hypertrophy, idiopathic inflammatory myopathy, proliferative myositis
, muscular dystrophy, lipomatosis, liposarcoma, rhabdomyosarcoma, and infiltrative leukemias and lymphomas.