Tiger man sign in sarcoid myopathy

Excerpt

A 53-year-old man presented to the emergency room with new-onset gait ataxia and muscle weakness of the proximal thighs. On physical examination, bilateral weakness of the proximal muscles of the thigh was noted. Laboratory tests returned a known mild leukopenia with 4,000 per cubic millimeter (reference range, 5,000–10,000) and slightly elevated angiotensin-converting enzyme levels with 120 U/liter (reference range, 20–70). All other results including complete blood counts, serum chemistry including muscle enzymes (creatine kinase and aldolase) and C-reactive protein (CRP) were unremarkable. For further whole-body work-up, positron emission tomography/computed tomography (PET/CT) with ¹⁸F-FDG was performed. Beyond highly hypermetabolic cervical, hilar, mediastinal and intraabdominal lymphadenopathy, numerous fascial and intramuscular lesions, particularly in the extremities were recorded (arrow) — a finding highly consistent with granulomatous myositis. Subsequent magnetic resonance imaging confirmed the PET/CT findings with diffuse contrast-enhancing granulomatous lesions (dotted arrow) that were mildly hyperintense on native T₁-weighted images and hyperintense on T₂-weighted images. Histopathology of respective muscle biopsy specimens revealed the presence of non-caseating granulomas. …