An Emergency Operation for Rectal Invagination due to the Lipoma of the Sigmoid Colon

Abstract

A 55-year-old woman presented with a prolapsed mass in the anus and severe pain. The tumor was not manually returned, and CT scan revealed a rectal invagination and a mass with fatty components. An emergency surgery to resect the sigmoid colon was performed. The mass measured 75 mm×55 mm and had smooth margins. The cut surface showed a xanthochromia. Histopathology showed growth of mature adipocytes located in the submucosal and subserosal layers. No lipoblasts and malignancies were observed. Lipoma of the sigmoid colon with prolapse through the anus occurs rarely.