A retroperitoneal pseudomyxoma of the appendix: A case report

Retroperitoneal pseudomyxoma (RP) is a rare condition characterized by mucinous tumor growth within the retroperitoneal space, commonly originating from the appendix or other abdominal organs. RP presents with non-specific symptoms such as abdominal pain, bloating, and weight loss, making accurate diagnosis challenging. Due to its rarity and symptom overlap with other conditions, RP requires careful management by a multidisciplinary healthcare team.

An 82-year-old female with a three-month history of abdominal pain and an abdominal mass underwent diagnostic imaging, revealing a retroperitoneal cystic mass. Exploratory laparotomy identified gelatinous masses originating from the retrocaecal appendix, which were resected. Histopathological examination confirmed a diagnosis of retroperitoneal pseudomyxoma with mucinous appendicular low-grade cystadenoma as the primary source. The patient had an uneventful postoperative course and remained disease-free at a 12-month follow-up.

RP's exact cause is unknown but often originates from the appendix, leading to mucinous fluid accumulation in the retroperitoneal cavity. This condition presents with varied symptoms, including abdominal pain and distension, mimicking other abdominal diseases. Diagnosis involves clinical, radiological, and pathological assessments, with imaging showing characteristic features. Treatment comprises surgical resection, potentially combined with HIPEC, aiming for complete cytoreduction. Prognosis depends on factors like tumor grade, extent, and cytoreduction completeness.

Retroperitoneal pseudomyxoma is a rare condition with challenging diagnosis due to its non-specific symptoms. Early recognition, surgical resection, and appropriate adjuvant therapies like HIPEC or chemotherapy can improve outcomes in patients with this uncommon disease.