Comments and illustrations of the WFUMB CEUS liver guidelines: rare benign hematological focal liver lesions (hepatic extramedullary hematopoiesis, Hemophagocytic lymphohistiocytosis, reactive lymphoid hyperplasia).

The manifestation of benign hematological infiltration in the liver is a challenge due to their rare occurrence and therefore, limited awareness and the general need for biopsy and histological confirmation. Owing to the rarity of these lesions, there are limited data concerning their appearance on ultrasound and, specifically, contrast-enhanced ultrasound. In a series of papers, we have compiled the US and CEUS characteristics of rare FLL, where there are few reports and images available, in order to build up a library of these cases. This paper describes the US and CEUS features of benign hematological FLL which include hepatic extramedullary hematopoiesis (EMH), hemophagocytic lymphohistiocytosis (HLH) and reactive lymphoid hyperplasia (RLH). Although these lesions occur rarely in the liver, their correct identification is imperative for appropriate patient`s management.