THE PRACTICING physician still faces many clinical problems in assaying the harmful potential of the ubiquitous fatty tumor. Because of the long-established belief that "all lipomas are benign," many lipomatous tumors are considered too casually and are accorded adequate study by neither the clinician nor the pathologist.
Whether a lipoma is malignant to begin with, or undergoes transformation into a malignant liposarcoma is not too significant. The great frequency of fatty tumors and the rarity of identified liposarcomas would suggest that the percentage of lipomas which undergo malignant transformation must be low. The fact remains, however, that a significant number of undifferentiated malignant liposarcomas do appear with both multiple and solitary lipomas. The two biopsy-confirmed liposarcomas appearing in multiple lipomas in our small series of case reports should indicate that this issue is far from settled.
These factors, plus our observation of the protean course of liposarcomas, the chronicity of
Sawyer KC, Sawyer RB, Lubchenco AE, Bramley HF, Fenton WC. The Unpredictable Fatty Tumor. Arch Surg. 1968;96(5):773-785. doi:10.1001/archsurg.1968.01330230081010