Objective To improve the diagnosis and treatment of benign renal tumor so as to avoid overtreatment.Methods The clinical data of 9 cases with benign renal tumor misdiagnosed as renal cell carcinoma treated from May 1999 to May 2011 were retrospectively analyzed.All cases were misdiagnosed as renal cell carcinoma with ultrasound or computed tomographic imaging before operation.Results All cases underwent surgical operation.For 1 case,frozen pathological test suggested a benign outcome.The tumor was enucleate accordingly.For another 7 cases,radical nephrectomy were performed.For the last 1 case,simple nephrectomy was performed.All cases were confirmed as benign by postoperative pathologic test,including 6 cases of renal angiomyolipoma,2 cases of renal oncocytoma,1 case of metanephric adeoma.Follow-up assessment lasted for (1-5) years without recurrence or metastasis.Conclusions It must be paid special attention to unique features which benign renal tumor shows in medical imaging.When the diagnosis is inconclusive,nephrectomy can be avoided by further intraoperative frozen pathological test to avoid overtreatment.

Objective To investigate the multi-drug resistance of Klebsiella strains and its mechanism.Methods Twenty strains of Klebsiella were isolated from the Affiliated Hospital of Medical College,Ningbo University from October 2009 to March 2011,in which 18 isolates were Klebsiella pneumonia and 2 were Klebsiella planticola. Drug sensitivity was determined by K-B tests. Drug resistant genes gyrA,parC (chromosome mediated) and aac( 6′)-I b-Cr,qnrA,qnrB,qnrS,qepA (plasmid mediated) were amplified by PCR and verified by direct automated fluorogenic sequencing. Results Resistance to β-1actams,aminoglycosides and quinolones was observed in 20 strains,and resistant rates were all above 80％.Klebsiella planticola strains were sensitive to imipenem and meropenem.Mutations of gyrA and parC genes existed in 18 strains (90％),and the positive rates of aac (6') -I b-C r,qnrB and qnrS were 60％ (12/20),20％ (4/20) and 20％ (4/20),respectively.Conclusion The mutations ofgyrA and parC genes may be the main cause of the resistance to quinolones in these strains.