Synchronous wilms tumor and fibrolamellar hepatocellular carcinoma: report of a case. 
Fibrolamellar hepatocellular carcinoma (FHCC) is a unique histologic variant of HCC that occurs in a younger subset of patients than classical HCC, and is associated with a better prognosis.  Wilms tumor (WT) is a malignant embryonal neoplasm of the kidney and is one of the most common solid tumors of childhood, occurring at an estimated frequency of 1 in 8000 to 10,000 births.  Although second malignant neoplasms (SMNs) following therapy for WTs have been reported in the liver, the coexistence of HCC and WT is extremely rare.  We present the first report of a synchronous anaplastic WT and FHCC in a previously healthy 4-year-old girl.  Despite the presence of focal immunohistochemical positivity for p53 in the WT, molecular analysis failed to reveal a germline or somatic p53 mutation, and was inconclusive in establishing a clonal relation between the two tumors.