Ciliated hepatic foregut cyst: an increasingly diagnosed condition.

BACKGROUND: Ciliated foregut cysts of the liver are rare, with only 96 cases diagnosed since the first description in 1857. They are being increasingly diagnosed recently; the majority of the cases have been reported in the last 15 years. Although they bear a close resemblance to the simple cyst of the liver which has essentially a benign course, ciliated hepatic foregut cysts (CHFCs) can progress to malignancy with devastating consequences. It is imperative that this group of conditions be diagnosed and treated adequately.

DATA SOURCES: This review includes discussion of the data from all the 96 reported cases from English and non-English literature. Analysis of the incidence rates, embryogenesis, growth, clinical features, risk of malignancy and the prognosis are highlighted systematically. The roles of various diagnostic modalities including ultrasound, CT, MRI, fine needle aspiration cytology (FNAC), immunohistochemistry and surgery are further discussed.

RESULTS: The mean age of patients with CHFC was 48+/-12 years. The male/female ratio was 1.1:1. The majority of patients with CHFC (62%) were asymptomatic, and the common mode of presentation was right upper abdominal pain. The cysts occurred in the left lobe in 51 patients, with sole location in segment IV in 44, and in the right lobe in 26. The average size of the cysts was 3.6+/-2.12 cm. The majority of the cysts were unilocular, and only 7 cases were multilocular. Cyst contents were described as viscous or mucinous in 73 patients, whereas bilious fluid was noted in 3. Large cysts having squamous carcinoma were cited in 3 patients, and 2 had extensive squamous metaplasia without malignancy. Others had benign histopathology.

CONCLUSIONS: Clinicians have become increasingly aware of CHFC. Imaging alone is not diagnostic per se, but when considered in the context of the global picture does provide important clues to the diagnosis. FNAC is diagnostic by the presence of the ciliated columnar aspirate but lacks sensitivity. Infantile presentation is usually accompanied by biliary communication and mandates a different surgical approach. The demonstration of malignant transformation in 3 cases and its fatal course emphasizes the need for surgical resection in all cases once the diagnosis is made.