Benign mesenchymoma of the retroperitoneum: A case report and literature review

Benign mesenchymoma is an uncommon tumor containing at least two or more differentiated mesenchymal elements in addition to fibrous tissue. Furthermore, benign mesenchymoma of the retroperitoneum in adults is a very rare disease entity. A 67-year-old man presented with abdominal distension which had progressed over more than 20 years. A huge abdominal mass had been noted 6 years previously. The patient was admitted to our hospital and received surgical intervention on account of changing bowel habits for 1 month. A huge retroperitoneal tumor weighing 10 kg was excised. Histopathology proved it to be a benign mesenchymoma (lipoma with osseous metaplasia). The postoperative course was uneventful. Herein, we report this case to discuss the clinical picture and review the literature.