Retroperitoneal Masson's haemangioma (intravascular papillary endothelial hyperplasia).

We present a case of an elderly female in her 70s admitted with right iliac fossa abdominal pain. MRI revealed a multiloculated retroperitoneal cystic lesion, initially suspected to be malignant but later identified as Masson's haemangioma following laparoscopic excision. This report highlights the rarity of Masson's haemangioma in the retroperitoneum and emphasises its distinction from other differential diagnoses.