INCIDENTAL FINDING OF RETROPERITONEAL NEOPLASIA: A CASE REPORT

Abstract

Case Presentation: A 40-year-old female patient sought care due to a coccyx fracture and an incidental finding of a tumor in the retroperitoneum. For histological investigation of the lesion, a computed tomography (CT)-guided biopsy was indicated, but this was not possible due to interposition of bowel loops. Surgical intervention was indicated, which resulted in retroperitoneal lymphadenectomy, removal of the retroperitoneal tumor, and omentectomy. The procedure was uneventful, and the patient was discharged on the 5th day and referred for outpatient follow-up. A return visit to the clinic revealed a pathological diagnosis of a benign, non-neoplastic cyst. Discussion: Retroperitoneal tumors are silent and are often detected incidentally during the investigation of other clinical conditions, as in the case presented. CT is the examination of choice in the initial evaluation of retroperitoneal masses because it allows detailed analysis of the lesion's extent, its relationship with adjacent structures, and morphological characteristics suggestive of benignity or malignancy. In the present case, CT was essential for precise localization of the lesion and guidance of subsequent diagnostic procedures. Histological confirmation is essential for diagnostic elucidation and therapeutic direction, with CT-guided percutaneous biopsy being the preferred option, especially in asymptomatic patients with accessible lesions. However, the literature highlights that the presence of interposed structures can represent a significant limitation, also increasing the risk of complications. In these cases, conversion to a surgical approach is indicated, and this approach was adopted in this case, with conversion to open biopsy after intraoperative identification of an interposed loop, a procedure that culminated in the performance of other procedures. Surgical treatment is considered the mainstay of treatment for retroperitoneal masses, especially when neoplasia is suspected or the diagnosis remains unclear. Although the anatomopathological diagnosis revealed a benign, non-neoplastic cyst, the adopted approach was justified given the technical limitations of percutaneous biopsy, the location of the lesion, and the need to exclude malignant pathologies. Final Comments: We conclude that retroperitoneal tumors (RPTs) represent a clinical and diagnostic challenge due to their deep anatomical location and nonspecific clinical presentation. The importance of an individualized approach is emphasized, especially in rare cases and those with atypical clinical presentations.