Intramuscular myxoma is a rare, benign, mesenchymal tumour. It contains fibroblast-like, histiocyt-like and myofibroblast-like cells in a myxoid material. These tumours occur in adults between 40 and 60 years with a predilection for women (70%). The incidence varies between 0.10 and 0.13/100.000. They may occur as an independent lesion or in conjunction with fibrous dysplasia or Albright syndrome. Although only circumstantial features have linked fibrous dysplasia and myxoma, the concept of a basic metabolic error of both tissues during initial growth period has been proposed. There are no specific clinical manifestations of this tumour. Although MRI offers the best imaging approach in terms of determination of the local extension of the tumour and its fatty texture, the differential diagnosis between intramuscular myxoma and myxoid degenerescence of a liposarcoma must be considered. The diagnosis is always made after microscopic examination. Local excision with histological margins free of tumour provides excellent local control without recurrence. The case of a patient presenting this rare tumour is presented. A thorough survey of the literature was done.