Colon Lipoma with intussusception
Colon is the most common gastrointestinal site for lipomas: about 60–70% of all lipomas of the gastrointestinal tract originate in the colon. Other than adenomas, lipomas represent the commonest benign neoplasm of the colon. Ninety percent of colonic lipomas arise in the submucosa and 10% in the subserosa (appendices epiploicae).
The majority of noncomplicated colonic lipomas will not cause clinical complaints. However, recurrent intussusception of the tumour may cause intermittent abdominal pain whereas ulceration of the mucosa overlying the tumour may lead to intestinal blood loss.
On barium study, the filling defect produced by lipoma is circular, ovoid or pear-shaped, abruptly marginated and with intact mucosal surface. The lesion mostly has a broad base but sometimes a pedunculated mass is depicted. A specific radiographic feature of colonic lipoma is that, due to its deformable and pliable nature, the lesion changes in shape on varying degrees of distension of the colon during filling.
On CT, a uniform attenuation
of fat (-60 to -120 HU) is revealed. CT plays also a very important role
in the visualization of the more rare subserosal forms, which because
of their exocolic location are usually not visualized on barium study.
Dr Ashok Raghavan, Manipal Hospital, Bangalore