潰瘍性大腸炎に合併しgastrocnemius myalgia syndrome様の症状を呈した非肉芽腫性筋炎の1例

The patient was a 36-year-old man. His initial symptom was bilateral thigh and calf pain. When he developed ulcerative colitis in the following year, he also noticed wasting of the calf muscles. The clinical feature is similar to gastrocnemius myalgia syndrome, although the left upper limb was also involved. A high-intensity lesion in the left calf and soleus muscles was observed on MRI, which was lead to the diagnosis of non-granulomatous myositis with infiltration of CD68-positive cells based on muscle biopsy. After steroids were administered, his pain subsided. Evaluation with needle EMG, MRI, and muscle biopsy is important when muscle pain accompanies inflammatory bowel disease.