Primary retroperitoneal mucinous cystic tumors are extremely rare. These tumors can be classified as a primary retroperitoneal mucinous cystadenoma with or without borderline malignancy or primary retroperitoneal mucinous cystadenocarcinoma. The most common of these is primary retroperitoneal mucinous cystadenoma, which almost always occurs in female patients; only ten cases have been reported in males. The most common clinical findings for this tumor type include nonspecific abdominal pain and a palpable abdominal mass. A definitive diagnosis is usually obtained from histopathology after surgical excision. Here, we report the case of a 60-year-old female patient who complained of abdominal pain that had been present for 3 mo and presented with a palpable abdominal mass. Multidetector computed tomography scanning revealed a large, unilocular cystic mass in the left retroperitoneal space. Surgical intervention was performed and the tumor was completely removed. Histopathologic examination confirmed that the tumor was a primary retroperitoneal mucinous cystadenoma. Two years after surgery, the patient remains disease free.
Keywords: Cystic tumor; Differential diagnosis; Histopathology; Mucinous cystadenoma; Retroperitoneum.