Crohn’s disease-related ‘gastrocnemius myalgia syndrome’ successfully treated with infliximab: A case report

Figure 1 Magnetic resonance imaging of the calves in axial and frontal views. A and C: Demonstration of high signal on T2-weighted images in muscles from posterior and lateral compartments of the legs as well as in their surrounding fascia; B: This finding was accentuated on gadolinium-enhanced fat-suppressed T1-weighted images, suggestive of myositis and fasciitis.

Figure 2 Biopsy specimen from the right gastrocnemius muscle showing the intense immune-inflammatory reaction. A: This hematoxylin and eosin-stained section shows the granulomatous nature (arrowhead) of this Crohn’s disease-associated skeletal myositis, predominating in the perimysial compartment; B: Discrete and focal immune infiltrates are found in the endomysium and around vascular structures (arrows); C and D: Immunohistochemical staining characterize immune cell-types involved therein: Co-staining for CD3 (brown staining) and CD20 lymphocytes (red staining) shown in C reveals predominance of CD3⁺ lymphocytes over CD20⁺ cells. CD4 and CD8 T cells subtyping shown in D (brown and red staining respectively) further reveals a slight predominance of CD8⁺ over CD4⁺ cells.