Sacral chordoma, evaluate response to therapy There are surgical changes of a partial sacrectomy extending from the level of S2 down with displacement of the rectum posteriorly, appearing similar to the prior study. There is increased fluid signal surrounding the rectum, likely representing a small amount of physiologic free fluid which is not significant in a patient of this age.Edema-type signal within the bodies of the pubic bones adjacent to the symphysis is likely degenerative in etiology.Innumerable nodular masses are again noted within the gluteus maximus musculature bilaterally as well as within the adjacent subcutaneous fat of the buttocks bilaterally. Additional nodular masses are situated along the posterior column of the acetabula adjacent to the obturator internus muscles, more so on the left than on the right. These masses are hypointense to skeletal muscle on T1 sequences and heterogeneously hyperintense to skeletal muscle on T2 sequences. Following contrast administration, they demonstrate heterogeneously, predominantly peripheral enhancement. One of the larger masses within the left gluteus maximus muscle again measures approximately 6 cm obliquely on series 9, images 13 through 15. A second mass within the subcutaneous fat between the intergluteal cleft and the medial margin of the left gluteus maximus (series 6 image 34) measures approximately 2.6 x 2.1 cm, similar to the prior exam. A smaller mass within the medial fibers of the right gluteus medius muscle (series 8 image 24) measures approximately 1.5 x 1.0 cm also similar to the prior exam. Multiple additional lesions are seen which appear similar in size and extent to the prior exam.
Innumerable masses within the posterior soft tissues as described above, presumably representing multifocal chordoma. When compared to the prior exam, overall these lesions appear similar in size and extent.