Large primary retroperitoneal mucinous cystadenoma: laparoscopic management and comprehensive literature review.

Primary retroperitoneal mucinous cystadenoma (PRMC) is a rare cystic tumor with unclear etiology and nonspecific clinical and radiological features, making preoperative diagnosis difficult. Due to its rarity, the optimal surgical management remains uncertain. We report a 60-year-old woman presenting with diffuse, colicky abdominal pain. Computed tomography and magnetic resonance imaging revealed a large, well-defined cystic mass in the right retroperitoneum measuring 12 × 9 × 10 cm, without evidence of local invasion. The patient underwent successful laparoscopic excision. Histopathological examination demonstrated a unilocular cyst lined by non-atypical mucinous epithelium without stromal invasion, confirming PRMC. The postoperative course was uneventful, and no recurrence was observed during follow-up. PRMC should be included in the differential diagnosis of retroperitoneal cystic masses. Histopathological evaluation is essential for definitive diagnosis. Complete surgical excision remains the treatment of choice, while laparoscopy may represent a safe and effective approach in selected patients when careful operative technique is applied.