Atypical lipomatous tumors have been described under a variety of names, such as "myxoma lipomatodes," "lipoma myxomatodes," "myxofibrolipoma" and "myxosarcolipoma," according to the structure of the tumor and the pathologist's point of view. The literature shows that most of these atypical lipomatous growths occur in the intramuscular tissue of the lower part of the body, especially in the groin and upper thigh. The term "lipoma pseudomyxomatodes" has been applied to certain of these atypical tumors, the fat cells of which they are principally composed being immature and atypical, capable of proliferating and forming a syncytium-like structure and producing a mucoid intercellular substance.
The case reported here of a tumor of this type is of interest because of the unusual location of the growth and because, possibly, the histologic observations may be a contribution to the interpretation of the myxomatous changes taking place in the structure of the tumor mass.
THOREK M, THOREK P. LIPOMA PSEUDOMYXOMATODES OF THE UPPER EXTREMITY. Arch Surg. 1934;28(6):1130-1135. doi:10.1001/archsurg.1934.01170180132008