Faculty Bibliography

OBJECTIVE:The purpose of this study was to clarify the frequency of and risk factors for liver abscess formation after transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma or metastatic hepatic tumors after undergoing bilioenteric anastomosis. MATERIALS AND METHODS/METHODS:From January 1996 to June 2012, 25 patients (21 men, four women; age range, 34-74 years) with hepatocellular carcinoma (n = 12) or metastatic hepatic tumors (n = 13) with an underlying bilioenteric anastomosis underwent 65 TACE procedures. The incidence of liver abscess, predisposing factors (diabetes, Child-Pugh class, leukopenia, tumor number, tumor size, tumor burden, tumor type, portal vein thrombus, lipiodol dose, particulate embolization, embolization selectivity, oily portogram, antibiotic prophylaxis, and occurrence of liver abscess at initial TACE), and clinical outcome were evaluated. Statistical analysis for relations between liver abscess and predisposing factors was performed by Fisher exact test and linear-by-linear association. RESULTS:Liver abscess developed after 17 of 65 (26.2%) TACE procedures performed on 12 of 25 (48%) patients. Two patients died of progression of liver abscess into sepsis. Univariate and multivariate analyses showed that leukopenia (p = 0.029), occurrence of liver abscess at initial TACE (p = 0.082), and particulate embolization or oily portogram (grade 2) (p = 0.001) were associated with a higher incidence of liver abscess. CONCLUSION/CONCLUSIONS:The incidence of liver abscess was high among patients with bilioenteric anastomoses who underwent TACE. Leukopenia, occurrence of liver abscess at initial session of TACE, and particulate embolization or oily portogram (grade 2) were associated with the development of liver abscess.

OBJECTIVE:The purpose of this study was to retrospectively assess the prevalence of segmental enhancement inversion of small renal oncocytomas according to tumor size. MATERIALS AND METHODS/METHODS:Thirty-three patients (19 men, 14 women; mean age, 61 years; range, 40-74 years) with 33 oncocytomas diagnosed at surgical resection who had undergone contrast-enhanced biphasic CT between January 2000 and December 2011 were included. CT scans were analyzed by two radiologists blinded to the specifics of the pathology report for size, presence of segmental enhancement inversion, enhancement pattern, and homogeneity. Segmental enhancement inversion was present when a renal mass was divided into two differently enhanced segments in the corticomedullary phase (30-40 seconds after contrast injection) with the degree of enhancement reversed in the nephrographic phase (120-180 seconds after contrast injection). The masses were further assessed for fibrous septa, cystic change, hemorrhage, and necrosis. For statistical analysis, the Pearson chi-square test and linear regression were used to evaluate the relation between the prevalence of segmental enhancement inversion and tumor size or pathologic changes. RESULTS:The mean diameter of 33 renal oncocytomas was 2.65 cm (range, 0.8-4.8 cm). There was no significant linear trend according to size (p = 0.762), although segmental enhancement inversion was significantly (p = 0.006) more common (10/12) in tumors measuring 1.5-2.9 cm. Pathologic change was present in 14 oncocytomas. There was no significant linear trend according to size (p = 0.068), but 2.5-cm and larger tumors had a significantly higher prevalence (57.9%) (p = 0.036). Segmental enhancement inversion was more common (13/19) in tumors without pathologic change (p = 0.024). CONCLUSION/CONCLUSIONS:Segmental enhancement inversion was a characteristic finding in our series of small renal oncocytomas and was more common in tumors measuring 1.5-2.9 cm. Pathologic changes such as central scar were more common in oncocytomas larger than 2.5 cm and may be related to the low occurrence of segmental enhancement inversion.

OBJECTIVE:We aimed to investigate the biological significance of signal transducers and activators of transcription 3 (STAT3) in gastric carcinoma. METHODS:Immunohistochemistry was performed on tissue array slides containing 285 gastric carcinoma specimens. The relationship between the nuclear expression of phospho-Tyr705-STAT3 (pSTAT3), an active form of STAT3, and prognosis, clinicopathological factors, proliferation, cell cycle regulators, apoptosis regulators, or angiogenesis-related proteins was evaluated. RESULTS:In nonneoplastic gastric mucosa, pSTAT3 was observed primarily in the nuclei of cells in the proliferative zone and intestinal metaplasia. In gastric carcinomas, nuclear STAT3 activation was observed in 36% of cases and was positively correlated with the Ki-67 labeling index and earlier tumor stage, whereas it was inversely correlated with lymphatic metastasis and distant metastasis (p< 0.05). Moreover, survival analyses showed that pSTAT3 expression was an independent prognostic factor of good survival. In addition, the expression of nuclear pSTAT3 positively correlated with that of cyclin D1, p21, p27, hypoxia-inducible factor-1α, or vascular endothelial growth factor (p< 0.05). CONCLUSIONS:STAT3 activation is an early event in gastric tumorigenesis and significantly correlates with better prognosis, proliferation and angiogenesis. Thus, STAT3 activation may be a valuable prognostic variable and therapeutic target in gastric carcinoma.