Fig. 2.

A. MRI STIR reveals featherlike oedema-type T2-hyperintensity enhancement of both tensor fascie latae muscles and distal psoas (mainly on the right side). B. Muscle biopsy revealed necrotic and regenerating muscle fibers. The numerous necrotic fibers appeared both scattered and in clusters. Lymphocyte infiltrates (CD3 and CD8 positive confirmed by immunohistochemistry staining) were mainly observed in relation to necrotic muscle fibers. There was upregulation of human leukocyte antigen class 1 in many fibers. The upregulation was patchy, not generalized.