Rare tumors of retroperitoneum-A diagnostic challenge

Abstract

Introduction: Retroperitoneum can show a wide spectrum of diseases, including a variety of rare benign and malignant neoplasms that can be either primary or metastatic. Most retroperitoneal tumors are malignant, and soft tissue sarcomas account for one third of the cases. The most common sarcomas occurring in the retroperitoneum are Liposarcomas, Malignant Fibrous Histiocytomas, and Leiomyosarcomas. Subtyping of these tumors is important for the different targeted therapeutic options available. Aims and Objectives: To study the distribution of benign and malignant retroperitoneal tumors. Materials and Methods: Study design – Prospective study done in the department of Pathology from January 2013 to December 2017. Immunohistochemistry (IHC) was done wherever necessary. Results: A total of 62 retroperitoneal tumours were studied of which 19 were benign & 43 were malignant. Rare benign tumors encountered were Adrenal Myelolipoma, Benign Fibrous Histiocytoma, Fibrolipomatous Hamartoma and multiple Paragangliomas. Rare malignant tumors were adult onset Wilms’ tumor, De-differentiated Liposarcoma, Epithelioid GIST, malignant GIST of the mesentery and Carcinosarcoma of Kidney. Conclusion: Amongst the retroperitoneal tumors received, malignant tumors were higher in distribution than benign tumors. The commonest epithelial tumor being Renal Cell Carcinoma and mesenchymal tumor being Liposarcoma. The study of rare malignant tumors was done with the help of IHC markers. Keywords: Retroperitoneum, Sarcoma, Immunohistochemistry, Epithelial, Mesenchymal, Rare tumors.