·         Uncommon tumors, but second in prevalence to adenomas for colonic tumors

·         Tend to occur more frequently in older females

·         Usually asymptomatic

·         When symptomatic, can produce:

o       Pain

o       Diarrhea

o       Rectal bleeding-if surface ulcerates

o       Constipation

·         Almost all are submucosal

·         Most are located on the right side (40%), but about 20% are in the sigmoid

o       In the small bowel, lipomas are more common proximally (duodenum)

·         Imaging findings

o       Usually less than 4 cm in size

o       Smooth, sharply defined hemispheric mass

o       Typically produces either right-angle or slightly obtuse angle as the lesion meets lumen of bowel

o       Rarely pedunculated

o       Squeeze-sign = deformity due to softness and compressibility of these lesions

§         Contour may be altered by peristalsis

o       Ulceration is rare

o       CT may demonstrate fatty nature of lesion, especially if they are large enough for accurate density measurements

 

Axial CT image of right lower quadrant shows a large, lobulated filling defect in the cecum
with well-circumscribed margins. The lower image demonstrates a negative Hounsfield values (-85HU)
consistent with fat. The lesion represents a lipoma of the cecum.

 

·         May intussuscept

·         Do not undergo malignant transformation