Since 1959, at least six cases of a peculiar high fixation of the bladder and sigmoid colon have been described, having in common a bizarre deformity and displacement of the pelvic viscera (1, 2). The appearance tended to simulate pelvic neoplasm, and all but one of the six underwent laparotomy, only to have it found that large amounts of normal or chronically inflamed fat filled the pelvis. The bladder was high in position and gourd-shaped, while the rectosigmoid colon was straightened and rose vertically from the lesser pelvis. We have recently collected and reviewed five additional cases which appear to represent the same abnormality first described by Engels in 1959, and we have elected to apply to them the term “pelvic lipomatosis.” This may be defined as an overgrowth of normal fatty tissue, limited to the perirectal and perivesical spaces in the pelvis. The name was chosen because of our belief that overabundant adipose tissue is the principal feature and perhaps the primary abnormality in all of t...