MR-IMAGING OF BENIGN FATTY TUMORS IN CHILDREN - REPORT OF 4 CASES ANDREVIEW OF THE LITERATURE

This study correlates the magnetic resonance imaging characteristics w ith the pathologic findings in rare benign fatty soft tissue tumors in four children. A review of the literature is presented. Two cases of infiltrating lipoma displayed bright signal on both T1- and T2-weighte d images, similar to that observed in subcutaneous fat. Histological s tudy revealed extensive muscle infiltration by mature fat, with some a reas of total fatty replacement. The case of facial lipomatosis reveal ed an extensive process of fatty invasion of adjacent soft tissue and osseous deformity by mass effect of the tumor. This lesion was bright on T1- and T2-weighted images. His topathologic examination showed wid espread invasion of squamous mucosa and skeletal muscle. The single ca se of lipoblastoma involved the presacral region and right buttock. Th is lesion, although bright on both T1 and T2 weighting, was relatively hypointense to subcutaneous fat on T1. Microscopic examination reveal ed a well-encapsulated fatty mass made up of cells ranging from lipobl asts to mature lipocytes. In childhood, when fatty lesions are almost always benign, a morphologic characterization by magnetic resonance ma y be sufficient basis on which to make critical therapeutic judgements .