Imaging spectrum of cholangiocarcinoma: role in diagnosis, staging, and posttreatment evaluation.

Cholangiocarcinoma, a tumor of biliary epithelium, is increasing in incidence. The imaging appearance, behavior, and treatment of cholangiocarcinoma differ according to its location and morphology. Cholangiocarcinoma is usually classified as intrahepatic, perihilar, or distal. The three morphologies are mass-forming, periductal sclerosing, and intraductal growing. As surgical resection is the only cure, prompt diagnosis and accurate staging is crucial. In staging, vascular involvement, longitudinal spread, and lymphadenopathy are important to assess. The role of liver transplantation for unresectable peripheral cholangiocarcinoma will be discussed. Locoregional therapy can extend survival for those with unresectable intrahepatic tumors. The main risk factors predisposing to cholangiocarcinoma are parasitic infections, primary sclerosing cholangitis, choledochal cysts, and viral hepatitis. Several inflammatory conditions can mimic cholangiocarcinoma, including IgG4 disease, sclerosing cholangitis, Mirizzi's syndrome, and recurrent pyogenic cholangitis. The role of PET in diagnosis and staging will also be discussed. Radiologists play a crucial role in diagnosis, staging, and treatment of this disease.

Microwave lung ablation complicated by bronchocutaneous fistula: case report and literature review.

Microwave ablation is a developing treatment option for unresectable lung cancer. Early experience suggests that it may have advantages over radiofrequency (RF) ablation with larger ablation zones, shorter heating times, less susceptibility to heat sink, effectiveness in charred lung, synergism with multiple applicators, no need for grounding pads, and similar survival benefit. Newer microwave ablation devices are being developed and as their use becomes more prevalent, a greater understanding of device limitations and complications are important. Herein we describe a microwave lung ablation complicated by bronchocutaneous fistula (BCF) and its treatment. BCF treatment options include close monitoring, surgical closure, percutaneous sealant injection, and endoscopic plug or sealant in those who are not surgical candidates.

Evidence of balancing selection at the HLA-G promoter region.

HLA-G is a class Ib HLA gene with unique tissue expression pattern and immunomodulatory properties. Polymorphisms in the HLA-G promoter region have been associated with miscarriage and asthma, whereas expression levels have been associated with a wide range of pathologic conditions as well as survival of embryos after in vitro fertilization and of organs after transplantation. Here, we characterize the sequence variation and haplotype structure of the HLA-G promoter and flanking sequences in 44 African Americans, 47 European Americans and 43 Han Chinese by haplotype-specific PCR and sequencing. In all three populations, we observed high levels of nucleotide variation, an excess of intermediate-frequency alleles, and a genealogy with two common haplotypes separated by deep branches, features that are suggestive of balancing selection acting in this region. Comparisons to HLA-A and a pseudogene, HLA-J, suggested that the observed pattern of sequence variation in the HLA-G promoter region is not likely due to other selected HLA genes. We suggest that the mechanism for this selection is related to the highly regulated expression pattern of HLA-G and that high- and low-expressing promoters may be favored under temporally and/or spatially varying selective pressures.