Pancreatic insulinomas: diagnosis and surgical treatment of 74 patients

Objective: To summarize retrospectively the experi- ence in diagnosis and surgical treatment of pancreatic insulinoma. Method: 74 patients who had been operated on and confirmed pathologically from July 1967 to July 2001 were enrolled. They were 37 men and 37 women, aged 41.91 years on average. Results: In all patients with typical Whipple's triad, the ratio of insulin to glucose was measured over 0.3 for at least one time. 52.70 % of the patients were once misdiagnosed, and only 20.27 % of them were correctly diagnosed in a year after onset of symp- toms. Their average course of the disease was 3.36 years. B-ultrasonography and endoscopic ultrasonog- raphy (EUS) showed a low positive rate for localiza- tion of insulinoma. CT and magnetic resonance ima- ging (MRI) could correctly detected 63.41% and 63.64 % of tumors respectively, in sharp contrast to a localization rate of 90 % for arterial stimulation and venous sampling (ASVS). Single insulinoma was ob- served in 66 patients (89.19 %), multiple insulinoma in 2 (2.70 %), hyperplasia in 4 (5.41%), and malig- nant insulinoma in 2 (2. 70%). Most (85. 29%) of the benign insnlinomas were less than 2 cm in diame- ter. Simple enucleation was the major operative pro- cedure for benign tumors. In 88. 52% of the pa- tients, glycemia increased to normal in 30 minutes after tumor excision, and in the remaining patients within 2 hours. 97. 26% of the patients experienced temporary hyperglycemia but recovered in a week. The major complications of insnlinoma included pan- creatic fistulae (27.27 %) and pancreatitis (5. 19 %). Conclusions: Better recognization of insulinoma and its rational examination are essential to early diagno- sis. CT can be first used for localization, otherwise ASVS is used. Surgery is the major choice for the treatment of insulinoma, but cautions should be taken to pancreatic fistulae after operation.

Primary adenosquamous carcinoma of the esophagus

AIM:To investigate the clinical characteristics,diagnosis,treatment,and prognosis of primary adenosquamous carcinoma(ASC)of the esophagus.METHODS:A total of 4015 patients with esophageal carcinoma underwent surgical resection between January 1995 and June 2012 at the Cancer Hospital of Shantou University Medical College.In 37 cases,the histological diagnosis was primary ASC.Clinical data were retrospectively analyzed from these 37 patients,who underwent transthoracic esophagectomy with lymphadenectomy.Theχ2or Fisher’s exact test was used to compare the clinicopathological features between patients with ASC and those with squamous cell carcinoma(SCC).The Kaplan-Meier and Log-Rank methods were used to estimate and compare survival rates.A Cox proportional hazard regression model was used to identify independent prognostic factors.RESULTS:Primary esophageal ASC accounted for0.92%of all primary esophageal carcinoma cases(37/4015).The clinical manifestations were identical to those of other types of esophageal cancer.All of the 24patients who underwent preoperative endoscopic biopsy were misdiagnosed with SCC.The median survival time(MST)was 21.0 mo(95%CI:12.6-29.4),and the1-,3-,and 5-year overall survival rates were 67.5%,29.4%,and 22.9%,respectively.In multivariate analysis,only adjuvant radiotherapy(HR=0.317,95%CI:0.114-0.885,P=0.028)was found to be an independent prognostic factor.The MST for ASC patients was significantly lower than that for SCC patients[21.0 mo(95%CI:12.6-29.4)vs 46.0 mo(95%CI:40.8-51.2),P=0.001].In subgroup analyses,the MST for ASC patients was similar to that for poorly differentiated SCC patients.CONCLUSION:Primary esophageal ASC is a rare disease that is prone to be misdiagnosed by endoscopic biopsy.The prognosis is poorer than esophageal SCC but similar to that for poorly differentiated SCC patients.

A Case of Primary Seminal Vesicle Cystadenoma

To the Editor:The primary seminal vesicle tumors are rare in clinical practice,[1] and the benign primary tumors are rarer.According to previous studies,the cystadenoma of seminal vesicle may possess various symptoms caused by different sizes and locations.Imaging and microscopic examinations could provide useful information in location and qualitative diagnosis.Here,we report a patient with benign cystadenoma on the right seminal vesicle.

Influence of carbon addition on mechanical properties of Fe-Mn-C twinning-induced plasticity steels

Mechanical properties and microstructural evolution of Fe-22Mn-0.6C and Fe-22Mn-1.0C(wt.%)twinning-induced plasticity(TwIP)steels were investigated by monotonic,stress-relaxation and unloading-reloading tensile tests.The dynamic strain aging(DSA)effect,resulting from pinning of dislocations,effectively improved the dislocation activation volume of the two TWIP steels.In the meanwhile,DSA-facilitated twinning nucleation mechanism kept similar twinning capabilities of the two TWIP steels.With strain increasing,the formation of high-density deformation twins restricted the dislocation motion and reduced the activation volume with increasing strain.Furthermore,C addition simultaneously improved the ultimate tensile strength and uniform elongation,and significantly enhanced the friction stress,rather than back stress.The stronger short-range order effect,brought by friction stress,promotes the planar dislocation slipping,thus improving the work-hardening capability.As a result,the additional work-hardening capacity can be achieved in Fe-Mn-C with higher C addition.