A Case of Multicentric Liposarcoma of the Right Perirenal Retroperitoneum, Ileum, and Mesentery of Small Intestine

Abstract

A 71-year-old female patient visited our hospital with a chief complaint of epigastralgia. Close examination revealed a right renal tumor and submucosal small bowel tumor. Right nephrectomy was performed in the urology department and the tumor was diagnosed as well-differentiated and partially dedifferentiated liposarcoma. Then, she was referred to our department for resection of a small intestinal tumor. Intraoperatively, we found a smooth, yellowish-white tumor which was 50 cm proximal to the terminal ileum, and multiple white nodules throughout the small bowel mesentery. We partially resected the small intestine with a part of white nodules. Histopathologically, the submucosal tumor was histologically similar to that of the right renal tumor, and immunostaining showed P16+, MDM2-, and CDK4+, to which we diagnosed a liposarcoma. Regarding the white mesentery nodule, the nodular adipose tissue that appeared to be contiguous from the fat of the mesentery grew irregularly, and immunostaining showed similar results, suggesting liposarcoma. We reported a rare case of multiple liposarcomas in the right perirenal retroperitoneum, ileum, and small bowel mesentery of the small intestine, along with a literature review.