Clinical and Imaging Features of Kaposiform Hemangioendothelioma in Infants.

Objective: Kaposiform hemangioendothelioma (KHE) is a locally aggressive tumor of vascular origin. This study investigated the clinical and imaging features of KHE to provide a reference for its early diagnosis. Methods: The clinical and imaging findings of 27 clinically confirmed KHE cases (including 21 with focal lesions and 6 with diffuse lesions) between January 2016 and December 2021 were retrospectively analyzed. Results: The mean age of the 27 patients was 105 & PLUSMN; 80.27 days. Twenty-two (81.5%) of these patients had Kasabach-Merritt phenomenon. Most KHEs were located in the trunk and/or ex-tremities (22/27). Ultrasonography showed heterogeneous echogenicity and/or striated hypo-echoic bands with abundant or patchy blood flow within the tumor. On plain computed tomography (CT), they appeared as heterogeneous lesions isodense with the muscles, with a CT value of 29.58 & PLUSMN; 11.53 HU. In the arterial phase, the KHEs showed striated or lamellar hetero-geneous enhancement, with a CT value of 153.91 & PLUSMN; 52.11 HU after enhancement. All KHEs showed uneven and high signal intensity on T2-weighted imaging, mixed high and low signal intensity on fat-saturated images, and no significant diffusion restriction on diffusion-weighted imaging. Conclusion: KHEs can occur in various locations and present as highly infiltrative and heteroge-neous masses that can invade the skin, adjacent muscles, and bones. A vascularized mass with purpuric skin changes, with uneven and high T2WI signal is highly suggestive of the diagnosis of KHE.