Abstract
Proliferative myositis is a rare, self-limiting, benign disease. Its diagnosis can be difficult and in many cases is not confirmed until after surgical resection. Herein, we report a case of proliferative myositis of the right brachioradialis in a 64-year-old man. The patient presented with a rapidly growing, painless mass in his right forearm. Magnetic resonance imaging and fine-needle aspiration biopsy led to a diagnosis of proliferative myositis. Complete surgical resection of the mass was performed. Postoperative pathological examination confirmed the diagnosis. To the best of our knowledge, this is the first report of proliferative myositis in the right brachioradialis. Fine-needle biopsy is helpful in the diagnosis of proliferative myositis, thus avoiding unnecessary surgical trauma and costs.