A Rare Case of Progressive and Invasive Adult Fibrosarcoma: Retroperitoneal Tumour Involving the Duodenum.

Retroperitoneal soft tissue sarcomas are rare tumors encountered in clinical practice. Their presentation often involves enormous size, and they are located in close proximity to vital anatomical structures, which, along with preoperative diagnostic uncertainty, pose significant challenges for treating physicians. Cross-sectional imaging is essential for defining the characteristics of these lesions and for planning an appropriate management strategy. Preoperative imaging-guided histopathology is recommended for pathologically classifying these tumors before embarking on any treatment plan. Management of these cases varies with different histological subtypes. Surgical resection forms the mainstay of therapy. Neoadjuvant/adjuvant chemotherapy and radiotherapy may play a role in selected cases. Here, we present a progressive and invasive case of adult fibrosarcoma in a young male who underwent surgical resection for this tumor.