Mucinous cystic neoplasm of the spleen with ovarian like stroma: a rare entity

Mucinous cystic neoplasms (MCNs) of the spleen are very rare, with a few reported cases in the literature. They are often confused with more common benign or parasitic splenic cysts due to very similar imaging features. We report a case of a 52-year-old woman with a giant multicystic lesion in the spleen, initially thought to be a hydatid cyst. Contrast-enhanced CT revealed a giant, cystic lesion. Surgical splenectomy was performed, and histopathology confirmed a mucinous cystadenoma with an ovarian-like stroma. Immunohistochemistry revealed estrogen and progesterone receptor positivity, confirming MCN. This case demonstrates the importance of considering MCN in the differential diagnosis of large, complex splenic cysts, even without pancreatic involvement. The presence of septations, wall calcifications, mass effect and absence of daughter cysts on imaging should raise suspicion for MCN. Histopathological evaluation remains gold standard, since preoperative imaging cannot reliably distinguish these rare neoplasms. Complete surgical resection is curative and essential due to the potential risk of malignant change. Awareness of splenic MCN is important for accurate pre-operative planning and definitive surgical management.