Mucinous cystic neoplasm of the liver with biliary communication: a great imitator, diagnostic dilemma and surgical challenge

TL;DR

A rare liver tumor called mucinous cystic neoplasm was mistaken for a hydatid cyst, highlighting diagnostic challenges and the need for accurate criteria.

Contribution

The paper reports a case of mucinous cystic neoplasm with direct biliary communication, a feature not previously included in diagnostic criteria.

Findings

MCN-L can mimic other cystic liver lesions, requiring histopathology for diagnosis.

Biliary communication in MCN-L can lead to complications like calculi and inflammation.

Current diagnostic criteria may need revision to include biliary communication.

Abstract

Mucinous cystic neoplasms of the liver (MCN-L) are rare tumours. We report a challenging case initially characterized as hydatid cyst. The patient underwent initial pericystectomy converted to completion left hepatectomy for definitive management. Histopathology confirmed MCN-L with focal high-grade dysplasia. Crucially, the resection specimen revealed a previously unrecognized finding: direct cyst rupture into the biliary tree, associated with bile encrustation, calculi formation, and inflammation. This case highlights that MCN-L can clinically and radiologically mimics other cystic liver lesions, necessitating histopathology for definitive diagnosis. The phenomenon of biliary communication and its sequelae are not readily accounted for in the current World Health Organization essential diagnostic criteria for MCN-L. Such cases may warrant the allowance of biliary communication within diagnostic criteria, to better reflect the spectrum of this lesion and avoid diagnostic pitfalls. Complete surgical excision is the mainstay of therapy, with long-term surveillance being essential, particularly in neoplasms with high-grade dysplasia.

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