Bilateral swelling of the forearms revealing muscular sarcoidosis: a case-based review

Muscular sarcoidosis is rarely symptomatic and mainly affects proximal muscles of the lower extremities. However, the distal localization in the upper extremities is rare. We used systematic approach to analyze all relevant literature review and we identified only three cases of muscular sarcoidosis of the upper extremities. We report the case of a 56-year-old woman who presented distal and bilateral swelling of the extensor surface of the forearms revealing muscular sarcoidosis. The laboratory exams associated elevated acute phase reactants with elevated serum angiotensin-converting enzyme levels and normal serum muscle enzymes. Ultrasound and MRI showed a bilateral and symmetrical muscle hypertrophy of the extensors of the fingers. Histological examination of muscle specimen and minor salivary gland biopsy revealed noncaseating epithelioid-cell granulomas. Therefore, the diagnosis of muscular sarcoidosis of the finger extensor muscles was made. Swelling of the forearms disappeared gradually under prednisolone 1 mg/kg/day. We used methotrexate as a steroid-sparing agent. Muscular MRI in sarcoidosis is not specific, but is to make a diagnosis of the lesion to optimize the biopsy which the cornerstone of the diagnosis ofsarcoidosis.