Invasive biliary mucinous cystic neoplasm: a review

Biliary mucinous cystic neoplasms (BMCNs) are recently redefined rare liver tumours in which insufficient recognition frequently leads to an incorrect initial or delayed diagnosis. A concise review of the subtle, sometimes non-specific, clinical, serologic and radiographic features will allow for a heightened awareness and more comprehensive understanding of these entities.

Literature relating to the presentation, diagnosis, treatment, pathology and outcomes of BMCNs and published prior to March 2012 was reviewed.

Biliary mucinous cystic neoplasms most commonly occur in females (≥60%) in the fifth decade of life. Clinical symptoms, serologic markers and imaging modalities are unreliable for diagnosis of BMCNs, which leads to misdiagnosis in 55-100% of patients. Perioperative cyst aspiration is not recommended as invasive BMCNs can only be differentiated from non-invasive BMCNs by microscopic evaluation for the presence of ovarian-type stroma. Intraoperative biopsy and frozen section(s) are essential to differentiate BMCNs from other cystic liver lesions. The treatment of choice is complete excision and can result in excellent survival with initial correct diagnosis.

A low threshold for considering BMCN in the differential diagnosis of cystic liver lesions and increased attentiveness to its subtle diagnostic characteristics are imperative. The complete surgical resection of BMCNs and the use of appropriate nomenclature are necessary to improve outcomes and accurately define prognosis.