Lollipop sign (hepatic epithelioid hemangioendothelioma)
The lollipop sign is seen in hepatic epithelioid hemangioendothelioma (HEHE). It represents hepatic/portal vein and/or their tributaries/branches tapering and terminating at or just within the edge of a well defined peripherally enhancing (or non-enhancing) lesion with an avascular core on CT or MRI images. This sign is a combination of two structures: the hypodense/hypointense well-defined tumor mass on enhanced CT/MRI images (the candy in the lollipop or target appearance) and the histologically occluded vein (the stick). This sign may improve the recognition of HEHE on cross-sectional imaging 1,2.
The target-like MR imaging appearance of HEHE tumors may be due to a central zone of fibrosis and a rim of cellular proliferation, with central signal hypointensity corresponding to hemorrhage, necrosis, or both, and peripheral hyperintensity corresponding to tumor cellularity and adjacent edema 2.
- 1. Alomari AI. The lollipop sign: a new cross-sectional sign of hepatic epithelioid hemangioendothelioma. (2006) European journal of radiology. 59 (3): 460-4. doi:10.1016/j.ejrad.2006.03.022 - Pubmed
- 2. Azzam RI, Alshak NS, Pham HP. AIRP best cases in radiologic-pathologic correlation: Hepatic epithelioid hemangioendothelioma. (2012) Radiographics : a review publication of the Radiological Society of North America, Inc. 32 (3): 789-94. doi:10.1148/rg.323115010 - Pubmed