A biliary cystadenoma was initially suspected and a laparoscopic approach was employed for tumor resection. The macroscopic cut section showed a brownish round unilocular cyst measuring 9.0 × 8.0 × 8.0 cm with a dense fibrous wall having small multifocal calcifications (Fig. 2A). The microscopic view of the cystic wall and small papillary remnants in that showed a dense fibrous wall without lining epithelium. The majority of the solid portion was almost completely necrotized and the remaining lesion had mono-layered endothelial cells and fibrous stroma mixed with blood cells, which indicated hepatic hemangioma (Fig. 2B and 2C). Immunohistochemical staining revealed strong positivity for cluster of differentiation 34 (CD34) and CD31 and negative for cytokeratin 19 (CK19), suggesting an endothelial origin (Fig. 2D). The cystic degeneration following the near-complete necrosis may have altered the presentation of this exophytic hemangioma into that of a cystic tumor.

Hepatic hemangiomas are the most common benign solid tumors in the liver. With ultrasound and CT scans becoming more accessible than ever, the detection of atypical hemangiomas mimicking malignant tumors has increased as well. As this case showed that a hepatic hemangioma can be misdiagnosed as a biliary cystic neoplasm. Thus, hepatic hemangiomas should be included in differential diagnoses of cystic tumors.

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