Malignant primary hepatic tumors in children include lesions unique to the pediatric age group and others that are more common in adults. Important considerations when evaluating a child with a liver tumor are the age of the patient, laboratory findings, and specific imaging features. The most common primary malignant hepatic tumor in the pediatric population, hepatoblastoma occurs almost exclusively in patients younger than 5 years with no history of liver disease. Hepatoblastoma is associated with elevated serum α-fetoprotein (AFP) level and appears predominantly solid. Hepatocellular carcinoma (HCC) is the most common malignant liver tumor in older children, often with a history of liver disease. HCC is associated with elevated serum AFP level and also appears as a solid mass. Fibrolamellar carcinoma occurs in adolescents without elevated AFP level and contains a T2-hypointense fibrous scar that usually does not enhance. Undifferentiated (embryonal) sarcoma occurs in young children, contains cystic and mucoid components, and mimics a cyst at magnetic resonance imaging and computed tomography but appears solid at ultrasonography. Epithelioid hemangioendothelioma is a multifocal vascular tumor in older children with a distinctive imaging appearance of confluent peripheral nodules with adjacent capsular retraction. Angiosarcoma rarely occurs in young children and frequently shows evidence of hemorrhage. Embryonal rhabdomyosarcoma of the biliary tree is unique to children, usually under 5 years of age, and frequently demonstrates an intraductal growth pattern. Knowledge of the pathologic features of these tumors and their imaging appearances can help radiologists offer an appropriate differential diagnosis and management plan.

Ligands of intermediate steric bulk were designed to mimic metalloenzymes with histidine and carboxlyate binding sites. The reaction between tris(3-isopropylpyrazolyl)methane and butyllithium followed by SO3NMe3 in THF yielded the new ligand lithium tris(3-isopropylpyrazolyl)methane sulfonate (LiTpmsiPr). Various metal salts reacted with LiTpmsiPr to give the octahedral complexes M(TpmsiPr)2 (M = Zn, Cu, Ni, Co, Fe) in which each ligand has N,N,O binding to the metal. In the reaction between LiTpmsiPr and ZnCl2, in addition to the major product Zn(TpmsiPr)2, [LiTpmsiPrZnCl2].2THF was also formed as a minor product with a tetrahedral zinc atom coordinated to either N,N,Cl,Cl in the solid phase or N,N,N,Cl in acetonitrile solution. Although TpmsiPr is coordinatively flexible and can act as a bipodal or tripodal ligand, it appears to favor the formation of octahedral L2M complexes.

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