[Mucinous cystic neoplasm of the liver].

Mucinous cystic neoplasms are rare benign tumours of the liver, accounting for less than 5% of all liver cysts. The exact etiology of mucinous cystic neoplasms is unclear, but female dominance and estrogen receptor positivity of ovarian type stromal cells suggest a role of hormonal factors in their development. The diagnosis is challenging as there are no specific laboratory or imaging characteristics, and the final diagnosis is often based on histological examination. A 27-year-old female patient was admitted to hospital with jaundice and abdominal pain. Laboratory results showed elevated levels of bilirubin and obstructive liver enzymes, while abdominal ultrasound revealed a septate cystic lesion in the liver. Further investigations - including ERCP, cholangioscopy assisted and percutaneous biopsy - did not provide clear diagnosis. Histological examination after surgical resection ultimately revealed a mucinous cystic neoplasm with low-grade dysplasia. Mucinous cystic neoplasms are rare liver tumours, and due to diagnostic difficulties, surgical intervention is often required. This case emphasizes that various non-surgical diagnostic methods might not be sufficient for establishing a final diagnosis. Orv Hetil. 2026; 167(26): 1041-1045.