A Case Report of Proliferative Myositis in Pectoralis Major Muscle

ABSTRACT

Proliferative myositis is very rare and was first described as a specific entity in 1960 by Kern. Proliferative myositis is a benign reactive condition that appears as a rapidly growing mass in the proximal muscles of the extremities of adults. Proliferative myositis can be confused with sarcoma clinically as well as microscopically. Proliferative myositis is a bizarre, self-limiting fibroblastic proliferation, the presence of very large basophilic cells with vesicular nucleoli and very prominent nucleoli which resemble ganglion cells or rhabdomyoblast, the cause of which is unclear. The symptoms are non-specific and the diagnosis always rests on a histological examination of the tissue. Local excision is curative and recurrence or metastasis has not been reported even when the abnormal tissue has not been completely excised. The authors report a case of Proliferative myositis in a 59-year-old male.