Efficacy of high resolution magnetic resonance imaging in preoperative local staging of rectal cancer

OBJECTIVE

To assess the efficacy of high-resolution magnetic resonance imaging (HRMRI) for preoperative local staging in patients with rectal cancer who did not receive preoperative radiochemotherapy.

METHODS

In this retrospective study, 30 patients with biopsy proved primary rectal cancer were evaluated by HRMRI. Two observers independently scored the tumour and lymph node stages, and circumferential resection margin (CRM) involvement. The sensitivity, specificity, the negative predictive value and the positive predictive value of HRMRI findings were calculated within the 95% confidence interval. The area under the curve was measured for each result. Agreement between two observers was assessed by means of the Kappa test.

RESULTS

In T staging the accuracy rate of HRMRI was 47-67%, overstaging was 10-21%, and understaging was 13-43%. In the prediction of extramural invasion with HRMRI, the sensitivity was 79-89%, the specificity was 72-100%, the PPV was 85-100%, the NPV was 73-86%, and the area under the curve was 0.81-0.89. In the prediction of lymph node metastasis, the sensitivity was 58-58%, the specificity was 50-55%, the PPV was 43-46%, and the NPV was 64-66%. The area under the curve was 0.54-0.57. When the cut off value was selected as 1 mm, the sensitivity of HRMRI was 38-42%, the specificity was 73-82%, the PPV was 33-42%, and NPV was 79-81% in the prediction of the CRM involvement. The correlation between the two observers was moderate for tumour staging, substantial for lymph node staging and predicting of CRM involvement.

CONCLUSION

Preoperative HRMRI provides good predictive data for extramural invasion but poor prediction of lymph node status and CRM involvement.

CONFLICT OF INTEREST

None declared.

Cooperative interaction of MUC1 with the HGF/c-Met pathway during hepatocarcinogenesis

Background

Hepatocyte growth factor (HGF) induced c-Met activation is known as the main stimulus for hepatocyte proliferation and is essential for liver development and regeneration. Activation of HGF/c-Met signaling has been correlated with aggressive phenotype and poor prognosis in hepatocellular carcinoma (HCC). MUC1 is a transmembrane mucin, whose over-expression is reported in most cancers. Many of the oncogenic effects of MUC1 are believed to occur through the interaction of MUC1 with signaling molecules. To clarify the role of MUC1 in HGF/c-Met signaling, we determined whether MUC1 and c-Met interact cooperatively and what their role(s) is in hepatocarcinogenesis.

Results

MUC1 and c-Met over-expression levels were determined in highly motile and invasive, mesenchymal-like HCC cell lines, and in serial sections of cirrhotic and HCC tissues, and these levels were compared to those in normal liver tissues. Co-expression of both c-Met and MUC1 was found to be associated with the differentiation status of HCC. We further demonstrated an interaction between c-Met and MUC1 in HCC cells. HGF-induced c-Met phosphorylation decreased this interaction, and down-regulated MUC1 expression. Inhibition of c-Met activation restored HGF-mediated MUC1 down-regulation, and decreased the migratory and invasive abilities of HCC cells via inhibition of β-catenin activation and c-Myc expression. In contrast, siRNA silencing of MUC1 increased HGF-induced c-Met activation and HGF-induced cell motility and invasion.

Conclusions

These findings indicate that the crosstalk between MUC1 and c-Met in HCC could provide an advantage for invasion to HCC cells through the β-catenin/c-Myc pathway. Thus, MUC1 and c-Met could serve as potential therapeutic targets in HCC.

Ectopic pancreas presenting with intractable diarrhea: case report

Ectopic pancreas is an uncommon congenital anomaly, which is usually found incidentally in clinical practice. It presents with nonspecific gastrointestinal symptoms like epigastric pain and dyspepsia and rarely with the clinical findings of obstructive jaundice or intestinal obstruction, or it may mimic gastrointestinal system cancer. Herein, we describe a case of ectopic pancreas in the duodenum, which was the cause of the intractable diarrhea. In our patient, upper gastrointestinal endoscopy and endoscopic ultrasonography revealed a 1.5 cm submucosal lesion, which was umbilicated centrally with a normal in appearance overlying mucosa. Endoscopic biopsy of the lesion was normal. Pathological examination of the lesion after surgical excision was compatible with ectopic pancreas. After total excision of the lesion, the clinical findings of the patient normalized. Ectopic pancreas presenting with diarrhea has not been reported previously in the literature.

Does glucagon like peptide-2 receptor expression have any effect on the development of human colorectal cancer?

BACKGROUND/AIMS

Glucagon like peptide-2 may play an important role in human colon cancer and polyp development because of its proliferative and antiapopitotic effects especially in colon. In this study, we investigated the role of human glucagon like peptide and it's receptor in development of human colorectal carcinogenesis.

MATERIAL AND METHODS

The study includes 30 patients in colon cancer group and 20 patients in colonic polyp group who have been diagnosed by endoscopic and pathologic examination in Dokuz Eylül University, Department of Gastroenterology within 2 year-period. For comparison biopsies were taken from normal appearing colonic mucosa of the same patient. The cancer, polyp and normal colon mucosa samples were stained with glucagon like peptide receptor antibody by immunohistochemical method.

RESULTS

Glucagon like peptide 2 receptor positivity of colon cancer patients was 20 % (6/30) in focal cytoplasmic coloration while it was 0 % in colonic adenomas and 100 % in enteroendocrine cells of normal colonic mucosa. Statistically significant differences were found by the comparison of colonic polyp and normal colonic tissue (p=0.000), colonic cancer and normal colonic tissue (p=0.000) and colonic polyp and cancer tissues (p= 0.023).

CONCLUSION

Glucagon like peptide-2 receptor expression in colonic adenomas was not detected in human in contrary to the study on mice. Our study suggested that Glucagon like peptide-2 receptor expression is not a factor in adenoma-cancer pathogenesis. More studies are needed on this subject with more facts and different methods.

A patient with nonfunctional pancreatic neuroendocrine tumor and incidental metachronous colon carcinoma detected by positron emission tomography: case report

Pancreatic neuroendocrine tumors constitute about 2% of all gastrointestinal neoplasms. Approximately half of the pancreatic euroendocrine tumors are nonfunctional. Due to lack of specific symptoms, most patients with nonfunctional pancreatic neuroendocrine tumors present with locally advanced or metastatic disease. Second primary malignancies are seen very rarely in these patients. Colon carcinoma ranks third in frequency among primary sites of cancer in both men and women in western countries. Presence of a metachronous colon adenocarcinoma in a patient with nonfunctional pancreatic neuroendocrine tumor has not been reported before. We present a patient who had an asymptomatic mass in the head of the pancreas, detected by ultrasonography in 1996. The patient did not consent to operation. In 2002, after the diagnosis of an unresectable, nonfunctional pancreatic neuroendocrine tumor, interferon alpha- 2b and octreotide were started. A year after biological treatment, he refused further treatment. In 2004, during the evaluation of dissemination of the asymptomatic disease, positron emission tomography revealed a high uptake by the descending colon despite the failure of other imaging methods. After surgery for operable colon carcinoma, the patient received chemotherapy and biological therapy for both tumors. Since 2005, he has been doing well without any further treatment thus far. In conclusion, computerized tomography/magnetic resonance imaging and octreotide scintigraphy may be insufficient to show disseminated disease and asymptomatic second primary malignancies. Therefore, positron emission tomography is a valuable promising option for the evaluation of gastroenteropancreatic neuroendocrine tumors and concomitant or metachronous malignancies. Lifelong follow-up by a multidisciplinary oncology team is needed so that a long-term survival can be achieved with integrated multimodal systemic treatment approaches.

The role of dynamic subtraction MRI in detection of hepatocellular carcinoma

PURPOSE

The aim of this study was to investigate the role of dynamic subtraction magnetic resonance imaging (MRI) in detection of hepatocellular carcinoma (HCC) in patients with cirrhosis.

MATERIALS AND METHODS

MR images of 32 patients with cirrhosis were retrospectively investigated. The standard sequence images of the patients were evaluated for detection of HCC, and then the subtracted images of dynamic contrast-enhanced series were evaluated. The sensitivity, specificity, and accuracy of standard technique and additional use of subtracted images were investigated.

RESULTS

In detection of at least one HCC, standard protocol was useful in 14 of 17 (82.3%) patients; by additional use of subtraction imaging all 17 (100%) patients with HCC were detected. For detection of the correct number of HCC tumors, standard protocol was found to have 61.5% sensitivity, 78.9% specificity, and 71.8% accuracy. The use of subtracted images increased the sensitivity to 85.7%, specificity to 83.3%, and accuracy to 84.3%.

CONCLUSION

Subtraction is a simple automatic procedure that is commonly available in most MRI systems. The use of subtraction of dynamic contrast-enhanced series facilitates the detection of HCC in disorganized architecture of cirrhotic livers.

Contribution of diffusion-weighted MRI to the differential diagnosis of hepatic masses

PURPOSE

To evaluate the diagnostic contribution of diffusion-weighted magnetic resonance imaging (MRI) using apparent diffusion coefficient (ADC) values to the characterization of hepatic masses and differentiation of benign and malignant lesions.

MATERIALS AND METHODS

The study included 30 patients that underwent upper abdominal MRI examinations because of hepatic masses that were found to be > or =1 cm in size with conventional sequences, and were additionally evaluated with diffusion-weighted MRI. Diffusion-weighted images and ADC maps in the axial plane were obtained using a 1.5 Tesla MRI device, single shot echo-planar spin echo sequences on 3 axes (x, y, z), and diffusion sensitive gradients with 2 different b values (b = 0 and b = 1000 s/mm (2)). Mean ADC measurements were calculated among the 30 cases involving 41 hepatic masses.

RESULTS

Of the 41 hepatic masses, 24 were benign and 17 were malignant. Benign lesions included 6 cysts, 14 hemangiomas, 2 abscesses, and 2 hydatid cysts. Malignant masses included 8 metastases, 4 hepatocellular carcinomas, 4 cholangiocellular carcinomas, and 1 gall bladder adenocarcinoma. The highest ADC values were for cysts and hemangiomas. The mean ADC value of benign lesions was 2.57 +/- 0.26 x 10(-3)mm(2)/s, whereas malignant lesions had a mean ADC value of 0.86 +/- 0.11 x 10(-3)mm(2)/s. The mean ADC value of benign lesions was significantly higher than that of malignant lesions (P < 0.01).

CONCLUSION

Diffusion-weighted MRI with quantitative ADC measurements can be useful in the differentiation of benign and malignant liver lesions.

A rare clinical entity misdiagnosed as a tumor: peliosis hepatis

Peliosis hepatis (PH) is a rare condition characterized by the presence of cystic, blood filled cavities within the hepatic parenchyma. Regardless of the reason, surgery should be performed under meticulous control of hemorrhage, if it is thought to be unavoidable. In this case report, ominous results of clinically misdiagnosed PH have been presented. PH should be kept on mind in all patients with hepatic mass, especially presented by sudden onset distention of the abdomen. Every effort should be done for the differential diagnosis with other cystic conditions like hydatid cyst in endemic areas.

Is rectal washout necessary in anterior resection for rectal cancer? A prospective clinical study

BACKGROUND

Implantation of exfoliated malignant cells has been suggested as a possible mechanism of tumor recurrence in colorectal anastomoses that might be prevented by cytocidal washout. The aim of our study was to assess whether malignant cells are likely to be collected by a circular stapler introduced transanally to perform an anastomosis and to observe local recurrences during follow-up, with special attention to the washout status of patients.

METHODS

Between May 1999 and March 2004, 96 patients with carcinoma of the rectum and distal sigmoid colon undergoing anterior resection under the care of three surgeons (only one of whom routinely performed rectal washout) were prospectively studied. While 38 patients had rectal washout with 5% povidone-iodine before anastomosis, 58 patients did not. A circular stapler was used for anastomosis, and the stapler was immediately rinsed in 100 ml of saline. The fluid was then classified as "acellular," "malignant cells identified," or "benign cells identified" by pathologists.

RESULTS

Malignant cells were collected from the circular stapler after use in 3 patients (8%) on whom rectal washout was performed and in 2 (3%) patients who did not have rectal washout performed (P=0.631). Three patients (8%) in the washout group developed local recurrence, and 2 patients (3.4%) in the no-washout group had local recurrence (one was anastomotic recurrence) (P=0.338). The median follow-up time was 23 (range: 9-70) months.

CONCLUSIONS

There were no differences in terms of the number of patients who had malignant cells collected from the circular stapler and local recurrence rates between the two groups. Although this is not a randomized study and size and mean follow-up time of the study were not sufficient, our results did not offer rational arguments in support of intraoperative rectal washout when a circular stapler is used after low anterior resection for carcinoma. Because of the limitations of our study, however, we are unable to arrive at a definite conclusion regarding rectal washout. There is a need for a randomized, controlled, large-scale, multicenter trial to establish the clinical relevance of intraoperative rectal washout.

Plexiform neurofibroma of the tongue: a case report of a child

A three-year-old girl with a lingual plexiform neurofibroma treated by total excision is presented. Despite their occurrence in the head and neck region, neural sheath tumors are rarely encountered in the oral cavity. It is reported that 4-7% of patients affected by neurofibromatosis display oral manifestations. Neurofibromatosis is characterized by café-au-lait spots and cutaneous neurofibromas. Plexiform neurofibroma is said to be indicative of von Recklinghausen's disease (VRD) even though it may be the only manifestation of the disease. Generally, surgical resection represents the treatment of choice and the diagnosis can only be confirmed after histological examination. Affected patients need regular follow-up to detect malignant degeneration, an early recurrence or appearance of other manifestations of VRD.

Efficiency of MR imaging in the detection of malignant liver lesions

PURPOSE

To evaluate the efficacy of preoperative magnetic resonance (MR) imaging in the detection of malignant liver neoplasms.

MATERIALS AND METHODS

MR images of 23 patients who had undergone hepatic resection or liver transplantation in the last two years were evaluated retrospectively. All MR imaging studies were performed with a 1.5 T magnet using a phased-array multi-coil. The MR imaging protocol was comprised of fat-suppressed T2-weighted TSE imaging, GRE with and without fat-suppressed T1-weighted imaging, and gadolinium-enhanced multiphasic dynamic GRE imaging. Images were reviewed on a PACS workstation by two independent abdominal radiologists. The image review was conducted on a lesion-by-lesion as well as segment-by-segment basis. MR imaging findings were compared with the results of pathology studies and intraoperative ultrasound examinations. Sensitivity, specificity, and positive predictive value (PPV) of MR imaging and interobserver variation were evaluated.

RESULTS

A total of 59 malignant liver lesions in 23 patients were identified by pathology studies and intraoperative sonographic examinations. Sensitivity and PPV of MR imaging on a lesion-by-lesion analysis were 68-86% and 85-89%, respectively; kappa=0.175 and agreement was 65.8% in these analyses. Sensitivity of MR images for small ( < 1cm) lesions was 13-67% and for large ( > 3 cm) lesions it was 100%. In segment-by-segment analysis, sensitivity and specificity of MR images were 87-95% and 97-98%, respectively; kappa=0.207 and agreement was 76.1%. Sensitivity and PPV of MR imaging in the detection of hepatocellular carcinoma were 46-85% and 55-73%, respectively.

CONCLUSION

Although MR imaging is generally a highly accurate method for the diagnosis of malignant liver tumors, it has some difficulty in detecting small lesions and hepatocellular carcinoma in cirrhotic livers.

Altered IGF-I receptor expression in chorioamniotic cells in premature rupture of fetal membranes

OBJECTIVE

To investigate the presence and distribution of type I insulinlike growth factor receptor (IGF-IR) in the cells of the chorioamniotic membrane and to search for any alterations occurring in IGF-IR expression in premature rupture of membranes (PROM) patients.

STUDY DESIGN

Fetal membranes collected at delivery from 42 pregnancies between 36 and 40 gestational weeks were included in the study. Seventeen of 42 cases had premature rupture of membranes, and 25 cases had intact membranes prior to delivery. Paraffin sections of thefetal membranes were stained with IGF-IR antibody by the streptavidin-biotin-immunoperoxidase method. The staining was scored and compared statistically between PROM and control cases.

RESULTS

The fetal membranes of PROM cases had significantly reduced IGF-IR expression in chorionic trophoblastic cells when compared with the control group (P = .006, X2).

CONCLUSION

Our immunohistochemical findings revealed that chanlges in IGF-IR levels in choriolzic amniotic cells may play a pathogenetic role in PROM cases, but the mechanism is speculative and needs further investigation.

The importance of cyclin D1 and Ki67 expression on the biological behavior of pancreatic adenocarcinomas

The aim of this study was to evaluate the role of cyclin D1 and Ki67 proteins involved in cell-cycle control as a prognostic factor in pancreatic carcinomas. We examined formalin-fixed, paraffin-embedded material from 59 pancreatic adenocarcinomas, for which appropriate clinical and prognostic data were available. The standard streptavidin biotin immunoperoxidase method was used for immunostaining with cyclin D1 and Ki67. The extent of positive nuclear and cytoplasmic cyclin D1 staining was graded semiquantitatively. Ki67 reactivity was quantified and expressed as the percentage of stained nuclei. Staining with cyclin D1 and Ki67 was compared with histopathological prognostic features, and their relation with survival was also tested statistically. Patients whose tumors were cyclin D1-positive showed perineural invasion significantly more frequently than did patients with cyclin D1-negative tumors at the immunohistochemical level. In addition, tumors with lymphatic vessel invasion and without showed a significant difference in terms of cytoplasmic cyclin D1 staining. Ki67 indices were statistically different in stage groups. There was a significant and direct correlation between Ki67 index and nuclear cyclin D1 staining scores. No relation with survival was found. Our results suggest that cell-cycle proteins do not directly affect the prognosis of patients with pancreatic adenocarcinoma. Conversely, cyclin D1-positive tumors tend to have perineural invasion more frequently. In addition, lymph vessel invasion is another factor related to cyclin D1 reactivity of the cells. Ki67 indices differ statistically in stage groups.

The effects of vascular bed expansion in steatotic rat liver graft viability

Disturbed microcirculation caused by fat accumulation in hepatocytes has been implicated in poor graft preservation and reperfusion. The aim of this study was to investigate the effect of vascular bed expansion (VBE) during cold preservation in graft survival Moderate liver steatosis in male Wistar rats (240-280 g) was induced by choline-deficient diet. Normal, steatotic or VBE-pretreated steatotic grafts were transplanted after 1 h or 9 h of cold preservation. Graft viability was determined by 7-day survival, serum liver enzymes, plasma tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, and malondialdehyde (MDA) levels. Post-reperfusion bile flow and liver histology were also examined. After 9 h of preservation, VBE-pretreated steatotic liver grafts were associated with significantly reduced serum liver enzyme, plasma TNF-alpha, IL-6, and MDA levels, as well as increased bile flow and higher survival rates compared with untreated ones. The present study shows that VBE protects fatty liver grafts from subsequent long-term cold preservation and reperfusion injury in a rat liver transplantation model.

Stereological quantification of placental villus vascularization and its relation to umbilical artery Doppler flow in intrauterine growth restriction

The aim of this study was to investigate the changes in the number of vessels within tertiary stem villi and intermediate/terminal villi which may be responsible for the abnormalities in placental vascular resistance and Doppler velocity index values in growth-restricted fetuses. The placentas of 20 cases with intrauterine growth restriction and 30 cases which were appropriate for gestational age were studied. The umbilical artery resistance index, pulsatility index and systolic to diastolic ratio were measured in each case. The vessels were quantified by a stereological method described previously and vascular surface density and the volume portion of the villi were calculated. The placentas of preterm and term cases with intrauterine growth restriction displayed significant reductions in the vascular surface density of stem and intermediate/terminal villi and volume portion of intermediate/terminal villi stroma when compared with gestation-matched normally grown cases (p<0.05). There was no significant correlation between Doppler index values of the umbilical artery and the stereological parameters of the intermediate/terminal and stem villi in the intrauterine growth restriction group (p>0.05). Some of the pregnancies with intrauterine growth restriction (six patients) with normal Doppler flow velocity waveforms had reduced vascularization in the placentas, and these pregnancies were found to have no perinatal complications. We conclude that,although the placental villi show reduced vascularization in pregnancies with intrauterine growth restriction, the Doppler indices may be normal and this normal flow pattern is related to reduced complication rate.

Immunohistochemical analysis of epidermal growth factor receptor in cyclosporin A-induced gingival overgrowth

Cyclosporin A (CsA)induced gingival overgrowth represents a tissue of fibrosis and epidermal growth factor (EGF) has been shown to induce extracellular matrix synthesis by fibroblasts. The purpose of this study was to evaluate the expression of EGF-receptor (EGF-r) in frozen sections of CsA-induced overgrown gingival tissue using immunohistochemical and semiquantitative techniques. Gingival biopsies were obtained from 12 renal transplant patients receiving CsA as well as 9 systemically and periodontally healthy individuals. Immunohistochemical staining procedures were carried out in frozen sections of gingival tissue and the expression of EGF-r was compared between the two study groups. The expression of EGF-r was more pronounced in the oral gingival epithelium of CsA-induced overgrown gingiva as compared to those of the clinically healthy gingival specimens. The reactivity in the inflammatory infiltrate and connective tissue cells of both of the study groups was similar. In conclusion, the results of the present study may suggest that CsA affects EGF-r metabolism in gingival keratinocytes resulting in an increased number of cell surface receptors, which may eventually play a role in the pathogenesis of gingival tissue alterations.

Prognostic significance of nuclear morphometry in superficial bladder cancer

OBJECTIVE

To evaluate the significance of nuclear morphometry in predicting the clinical course in superficial (pTa and pT1) bladder cancer.

STUDY DESIGN

The study included 73 patients with superficial transitional cell carcinoma of the bladder who were followed for a median of 21 months (range, 1-90). Nuclear morphometry was performed by a computer-assisted image analyzer system on hematoxylineosin-stained histologic sections and characterized by five nuclear variables: area, perimeter, major and minor diameter, and form factor. Patient charts and microscopic slides were reviewed to record tumor stage, grade and size. Tumor proliferative activity was assessed by immunohistochemical staining with Ki-67 antibody.

RESULTS

None of the morphometric variables showed a significant relation to tumor progression and recurrence. Higher values of mean nuclear area, perimeter, and major and minor diameter were significantly related to higher grade and proliferative activity. Mean nuclear area and minor diameter were associated with advanced stage. Of established prognostic factors, only histologic grade was significant in predicting progression.

CONCLUSION

The results suggest that nuclear morphometry may be valuable in determining proliferative activity and may be well correlated with histologic grade in superficial bladder cancer. However, like many other potential prognostic factors, it seems to be unreliable in predicting clinical behavior.

Does angiogenesis predict recurrence in superficial transitional cell carcinoma of the bladder?

OBJECTIVES

To investigate the role of angiogenesis in predicting tumor recurrence and its correlation with established clinicopathologic prognostic factors in superficial transitional cell carcinoma of the bladder.

METHODS

The paraffin sections of 80 superficial papillary transitional cell bladder carcinoma specimens were stained with CD31 antibody to label the vascular endothelium using the standard streptavidin-biotin-immunoperoxidase method. The vascular surface density (VSD) equivalent to the vascular surface area per unit of tissue volume and number of vessels per square millimeter of stroma (NVES) were assessed by means of stereology, and these morphometric parameters of angiogenesis were statistically analyzed to interpret the relation to tumor recurrence in addition to tumor stage, grade, size, and number and the presence of carcinoma in situ.

RESULTS

VSD and NVES values showed no statistically significant difference between pTa and pT1 tumors or patients with and without recurrence. In contrast, VSD and NVES values were found to increase in higher grade tumors (P = 0.019). VSD values were also higher in patients with coexisting carcinoma in situ in pTa tumors (P <0.001). Tumor number and size and recurrence number and time to the first recurrence did not correlate with any vascular parameters.

CONCLUSIONS

Stereologic assessment of angiogenesis does not help to predict recurrence in superficial bladder cancer. Angiogenic parameters appeared to be well correlated with the conventional histologic grading system. Otherwise, the present study did not show any correlation of angiogenesis with any potential prognostic factors. This may be due to the diverse angiogenic pathways occurring in invasive and superficial tumors.

Pancreatic adenocarcinoma: detection and staging with dynamic MR imaging

OBJECTIVE

To compare the efficacy of dynamic contrast-enhanced MR imaging and spin-echo T1-weighted with and without fat-saturated MR imaging in the detection and staging of pancreatic adenocarcinoma.

METHODS AND MATERIAL

Spin-echo T1-weighted, fat-saturated T1-weighted and dynamic breath-hold 2D-FLASH MR imaging were performed in 25 patients with pancreatic adenocarcinoma. MR images were analysed by calculating the CNR between tumor and normal portion of the pancreas. The CNRs calculated at each sequences were compared. A total of 16 out of 25 patients underwent surgery. Preoperative staging according to TNM classification was also done in patients undergoing surgery.

RESULTS

The CNR was significantly different (P<0.05) in the arterial phase of dynamic MR images. The accuracy of 'T' staging was 75% for SE T1-W, fat-saturated T1-W and arterial phase of dynamic MR images.

CONCLUSION

The CNRs between pancreatic carcinoma and normal pancreas is significantly higher in dynamic MR sequences than the SE T1-W, fat-saturated T1-W sequences. However, the accuracy of tumor staging according to TNM is equivocal to SE T1-W and fat-saturated T1-W images.

Tumor angiogenesis as a prognostic predictor in pancreatic cancer

The purpose of this study was to evaluate the role of angiogenesis, proliferative activity (assessed by Ki-67 expression), p53 and ras-oncogene (H-ras) expression, and conventional clinicopathologic factors in predicting overall survival rates in patients with pancreatic ductal adenocarcinoma. We followed-up 22 patients with ductal adenocarcinoma of the pancreas for a median of 19 months (range, 2 to 44 months). Angiogenesis was quantitated as vascular surface density (VSD) and the number of vessels per mm2 stroma (NVES) after microvessels were immunostained, using factor VIII-related antigen. p53, H-ras, and Ki-67 proteins were also determined immunohistochemically. VSD and NVES showed significant correlations with increased proliferative activity, poor tumor differentiation, and tumor size of 3 cm or more (P = 0.001, P = 0.013, and P = 0.047, respectively). The overall 2-year survival rate of 33.3% in patients with high VSD and NVES values was significantly worse than that of 66.6% estimated in patients with low microvessel count (log rank, 3.97; P = 0.046). In multivariate analysis using the Cox model, VSD was found to be an independent prognostic factor of survival (P = 0.039). H-ras and p53 expressions were not correlated with angiogenesis parameters. We conclude that, in pancreatic ductal adenocarcinoma, angiogenesis is closely related to tumor growth and patient survival.

Quantification of tumor cellularity and mitotic index in invasive ductal carcinoma of the breast

OBJECTIVE

To evaluate the use of stereologically estimated tumor cell counts in the mitotic index as well as to investigate its correlation with the currently used method and test the reproducibility of the method.

STUDY DESIGN

The stereologic method described by Simpson et al was used to estimate tumor cellularity in 50 invasive ductal carcinomas. Mitotic counts were also performed, and the mitotic index was calculated by the use of estimated tumor cell counts. Estimated cell counts and the mitotic index calculated were compared statistically with the actual cell counts and the traditional mitotic grades, respectively. Interobserver reproducibility of the method was also tested.

RESULTS

Stereologically estimated tumor cell counts had a good correlation with actual cell counts (r = .891, P < .001). Besides, the mitotic indices calculated with tumor cell counts (calculated with both estimated and actual cell counts) in the denominator of the fraction of the mitotic index were in agreement with the currently used method (P < .01 for both). There was no statistically significant difference between the counts of two observers (P = .068).

CONCLUSION

The suggested method, considering tumor cellularity as an influencing factor, was practical, reproducible and in agreement with the traditional method. This method should be studied in a large group of patients with follow-up data to determine the threshold values for different grades and determine its prognostic value during the disease course.

Angiogenesis and p53 and H-ras mutations in pancreatic ductal adenocarcinoma

OBJECTIVE

To evaluate the correlation of angiogenesis and p53 and H-ras mutations with prognostic factors and proliferative activity assessed with Ki-67 protein expression by studying archival tissues from 24 patients with primary pancreatic ductal adenocarcinoma.

STUDY DESIGN

Vascular structures were labeled immunohistochemically using factor VIII-related antigen. Vascular surface density (VSD) and microvessel number (NVES) were assessed by stereology. The tissues were also analyzed with the immunohistochemical method for the expression of proteins, including p53, H-ras and Ki-67.

RESULTS

Statistical analysis revealed that tumors with greater NVES and VSD values significantly correlated with occurrence of metastases, higher proliferative activity, poorer histologic differentiation and greater tumor size. p53 Mutations were found in 11 cases (45.8%). However, only three cases (12.5%), all negative for p53 mutations, showed H-ras mutations. p53 Mutation-positive tumors exhibited a statistically significant correlation with occurrence of metastases and higher proliferative activity, whereas H-ras mutations did not show such a correlation.

CONCLUSION

Angiogenesis might have a role in predicting prognosis in pancreatic carcinomas, and p53 mutations might be acquired in later stages associated with metastatic progression and higher proliferative activity. Although H-ras mutations were rare in the present study, they might play a role in a different carcinogenic pathway excluding p53 mutations.

Ki-67 immunostaining and stereologic estimation of nuclear volume in melanocytic skin tumors

OBJECTIVE

To investigate the proliferative activity and mean nuclear volume (MNV) of melanocytic skin tumors.

STUDY DESIGN

Proliferative activity, assessed by immunostaining for the Ki-67 monoclonal antibody (reactive with all actively cycling cells), and MNV, estimated by means of a stereologic method, were determined in 60 cutaneous melanocytic tumors, including 28 primary malignant melanomas (PMM), 13 compound nevi (CN), 11 dysplastic nevi and 8 metastatic malignant melanomas.

RESULTS

Both MNV and Ki-67 expression differed significantly between CN and other melanocytic tumors and showed a good correlation with Clark's level (a well-established prognostic parameter in PMM).

CONCLUSION

The association of proliferative activity and quantitative nuclear features may be helpful in the interpretation of the degree of malignancy in melanocytic skin tumors.

Stereological estimation of mean nuclear volume and staining pattern of Ki-67 antigen in keratoacanthomas and squamous cell carcinomas

Keratoacanthomas and squamous cell carcinomas of the skin share many histopathologic features, making differential diagnosis difficult. The aim of this study is to investigate the staining pattern of proliferating cells in keratoacanthomas and squamous cell carcinomas of the skin and to evaluate the value of nuclear morphometric criteria in differential diagnosis. Mean nuclear volume was assessed in 21 keratoacanthomas and 21 squamous cell carcinomas in tissue sections by a stereologic method. Immunohistochemical expression of Ki-67 monoclonal antibody was assessed and the distribution pattern (random or peripheral) of proliferating cells evaluated. Mean nuclear volume (MNV +/- SD) was 590 +/- 293.0 for squamous cell carcinomas and 615 + 305.9 for keratoacanthomas. Statistical analysis showed no significant differences between both groups (p = 0.78) in terms of mean nuclear volume values. Proliferating cells in keratoacanthomas showed a peripheral distribution, whereas there was a random distribution of proliferating cells in squamous cell carcinomas. Our results indicate that quantitative nuclear features are not helpful in making a differentiation between keratoacanthomas and squamous cell carcinomas, while immunohistochemistry with Ki-67 antibody may give useful additional information in differential diagnosis.