A Retroperitoneal Peritoneal Cyst, a Rare Cystic Lesion, Case Report

Background: Retroperitoneal cystic masses are benign fluid filled lesions arising within the retroperitoneal space surrounding the organs of the compartment. Peritoneal cysts are defined as tumors of the abdomen and pelvic peritoneum. Both are rare conditions that commonly assume an asymptomatic presentation, posing a challenge in diagnosis. Case presentation: A 42-year-old male was admitted to the surgical ward for right lower abdominal pain which had been present for one year. Ultrasound revealed that the mass was cystic in consistency and localized to the right side of the urinary bladder having debris and multiple calcifications. Intraoperatively, a retroperitoneal mass (cyst) about (9×9cm) in size was found adherent to the surrounding tissue, and when opened, fluid and mucus gelatinous material with debris and two staghorn stones (3×3cm) were found inside it. The mass extended downward through the right femoral canal to the thigh. An incision below the right inguinal ligament was done, and another stag horn of (3×3cm) size was found inside it. Total excision of the whole cyst was performed. Fluid was sent for cytopathology for microscopic examination, and the result was negative for malignancy. Conclusion: A rare incidence of retroperitoneal peritoneal cyst grows to massive measures and thus leads to nonspecific abdominal symptoms. Total excision is the treatment of choice for this case.