Andrea Casaril

Mucinous cystic neoplasms of the liver: a clinicopathological study and comparison with intraductal papillary neoplasms of the bile duct

Mucinous cystic neoplasm of the liver has been a controversial entity, in particular, regarding differentiation from intraductal papillary neoplasm of the bile duct. In this study, we compared the characteristics of hepatic mucinous cystic neoplasms with ovarian-like stroma (n=29) to those of cyst-forming intraductal papillary neoplasms of the bile duct (n=12). Radiological or macroscopic appearance, histological grade of malignancy, and postoperative clinical course were recorded. Immunohistochemistry for biliary or gastrointestinal markers was performed to characterize cell phenotypes. The patients with hepatic mucinous cystic neoplasm were all female and ranged in age from 21 to 67 years, which was significantly younger than that in the patients with biliary intraductal papillary neoplasm. Eighteen mucinous cystic neoplasms (76%) were located in the left lobe, with 13 (54%) in segment IV. Mucinous cystic neoplasms were significantly larger than intraductal papillary neoplasms (median diameter: 110 vs 50 mm, P=0.008). In contrast to intraductal papillary neoplasms that were all histologically malignant, 26 mucinous cystic neoplasms (90%) were adenomas, 2 (7%) were borderline malignant, and 1 (3%) was a carcinoma in situ. Benign mucinous cystadenomas had the pure biliary immunophenotype, whereas gastrointestinal markers including cytokeratin 20 and mucin core proteins 2, 5AC, and 6 were more frequently expressed in borderline or malignant mucinous cystic neoplasms and biliary intraductal papillary neoplasms. There was no mortality in the patients with mucinous cystic neoplasm, whereas one patient with intraductal papillary neoplasm died of cancer. In conclusion, hepatic mucinous cystic neoplasms and biliary intraductal papillary neoplasms have different clinicopathological characteristics as evidenced by differences in the age and gender of patients, macroscopic appearance, immunophenotypes, and grades of malignancy.

Lactobacillus plantarum Reduces Infection of Pancreatic Necrosis in Experimental Acute Pancreatitis

Background: Infection is the commonest cause of death in acute pancreatitis. Early reduction of commensal flora (particularly Lactobacillus species) and, at the same time, overgrowth of Enterobacteriaceae, especially Escherichia coli, have recently been described during acute pancreatitis. Lactobacillus plantarum has been shown to be effective in reducing the egress of endotoxin and microbial translocation in several experimental models such as chemically induced hepatitis and ulcerative colitis. Aim: The aim of the study was to determine whether L. plantarum 299v (Lp 299v) is capable of effectively reducing microbial translocation in experimental pancreatitis. Methods: Acute pancreatitis was induced by isolation and ligation of the biliopancreatic duct in Lewis rats weighing 250–350 g. The animals were divided into 3 groups: group A, sham operation; group B, induction of pancreatitis and no further treatment, and group C, induction of pancreatitis + daily administration by gavage of a 5-ml/day suspension of Lp 299v at 0.5–1.0 × 109 bacteria/ml for 8 days, 4 days before and 4 days after induction of pancreatitis. All animals were sacrificed after 96 h. Histological studies and microbiological analyses were performed. Results: At sacrifice, 40/55 animals showed signs of severe pancreatitis. Since acute pancreatitis was the specific disease investigated, only these animals were subjected to further study. In group B, we found pathogenic micro-organisms in the mesenteric lymph nodes in 14/20 animals and in the pancreatic tissue in 10/20. The bacterial flora consisted predominantly of E. coli, Enterococcus faecalis, Pseudomonas and Proteus species. In contrast, when the animals were kept under an ’umbrella’ of Lp 299v, growth of E. faecalis or E. coli were detected only in 4/20 mesenteric lymph node cultures and in 3/20 pancreatic tissue cultures. Conclusions:Lp 299v is effective in reducing microbial translocation in experimental pancreatitis. Treatment with probiotic bacteria seems to be a promising alternative to antibiotic therapy.