Macrodistrophia Lipomatosa is a congenital malformation of rare finding and unknown pathogenic mechanism. The pathology is mainly characterized by the interest of lower extremities and peculiar macroscopic feature is the presence of hyperthrophic fibro-adipose tissue. In our experience the localization to the upper extremities and the presence of uncommon clinical signs show the importance of instrumental investigation: MRI and CT for an accurate examination and to exclude other types of localized gygantism.