RETROPERITONEAL FIBROSARCOMA, A RARE ENTITY

The extreme rarity of retroperitoneal fibrosarcoma warrants reporting of all cases. The incidence of soft tissue tumors in retroperitoneum is 15 percent and the incidence of adult retroperitoneal fibrosarcoma is 1 percent. It is malignant or intermediate (rarely metastasizing) tumor usually involving deep tissues of the extremities, trunk, head and neck of middle-aged and older adults. Most patients of the retroperitoneal fibrosarcoma present with an asymptomatic abdominal mass. Contrast enhanced Computed Tomography remains the primary imaging modality for evaluation in a soft tissue sarcoma of retroperitoneum. Primary surgical resection with adequate margin is the dominant therapeutic modality. Adjuvant radiotherapy may be given to achieve local control in case of recurrence. Chemotherapy can be given to patients with liver metastasis using cyclophosphamide, vincristine, farmorubicin, and dacarbazine. A forty five years post menopausal female presented with a mass in abdomen associated with pain for past three months. The mass along with the left kidney was resected in toto. Histopathological examination was suggestive of spindle cell sarcoma morphologically malignant peripheral nerve sheath tumor but immunohistochemistry revealed it to be fibrosarcoma (report attached as image). This case is presented for its rarity and diagnostic confirmation by immunohistochemistry.