[Evaluation of left ventricular volumes and ejection fraction by gated myocardial perfusion SPECT versus cardiac MRI].

It is stated that cardiac MRI imaging can provide accurate estimation of left ventricular (LV) volumes and ejection fraction (EF). The purpose of this study was to evaluate the accuracy of gated myocardial perfusion SPECT for assessment of LV end-diastolic volume (EDV), end-systolic volume (ESV) and EF, using cardiac MRI as the reference methods/(methodology). Gated myocardial perfusion SPECT images were analyzed with two different quantification software, QGS and 4D-MSPECT. Thirty-four consecutive patients were studied. Myocardial perfusion SPECT and cardiac MRI had excellent intra/interobserver reproducibility. Correlation between the results of gated myocardial perfusion SPECT and cardiac MRI were high for EDV and EF. However, ESV and EDV were significantly underestimated by gated myocardial perfusion SPECT compared to cardiac MRI. Moreover, gated myocardial perfusion SPECT overestimated EF for small heart. One reason for the difference in volumes and EF is the delineation of the endocardial border. Cardiac MRI has higher spatial resolution. We should understand the differences of volumes and EF as determined by gated myocardial perfusion SPECT and cardiac MRI.

Lipomatous Pseudohypertrophy of the Pancreas Taking the Form of Huge Massive Lesion of the Pancreatic Head.

A 70-year-old woman presented with hypogastric pain. Computed tomography and magnetic resonance imaging revealed a retroperitoneal tumor 18.0 cm in diameter with fatty tissue density, ventrally compressing the pancreatic head. We suspected a well-differentiated liposarcoma compressing the pancreas. At laparotomy, the tumor mass was the size of an infant's head; its center was located in the area corresponding to the pancreatic uncus. It was continuous with the pancreatic parenchyma through a poorly demarcated border, and we resected as much of the tumor mass as possible while conserving the pancreatic capsule. Histopathological examination indicated lipomatous pseudohypertrophy of the pancreas with proliferation of mature fatty tissue as the main constituent. At the periphery, islands of acinar tissue were retained among the fatty infiltration, which also contained branches of the pancreatic duct and islets of Langerhans. Previous reports have stated that this disorder only causes fatty replacements throughout the pancreas or in the pancreatic body and tail; however, in this patient, imaging and macroscopic examination revealed no fatty replacements in the pancreatic body and tail. We report this case, which we consider extremely rare, along with a brief review of the literature.

Expression of matrix metalloproteinase 7 is an unfavorable postoperative prognostic factor in cholangiocarcinoma of the perihilar, hilar, and extrahepatic bile ducts.

Cholangiocarcinoma of the perihilar, hilar, and extrahepatic bile ducts (collectively referred to as the large bile ducts) is an intractable disease, and a papillary phenotype and well-differentiated histologic grade have been proposed as indicators of a favorable prognosis after surgical resection. In this study, we examined the significance of matrix metalloproteinases (MMPs) in cholangiocarcinoma with respect to clinicopathologic features. We subjected 66 surgically resected specimens of cholangiocarcinoma of the large bile ducts to clinicopathologic examination, including postoperative survival, papillary phenotype, and immunohistochemical expression of MMP-2,-7, -9, and membrane type 1 MMP (MT1-MP). Nonneoplastic biliary epithelium did not express these 4 MMPs, whereas cholangiocarcinoma frequently expressed MMP-2 (33.9%), -7 (75.8%), -9 (47.5%), and MT1-MMP (54.5%). In particular, conventional (nonpapillary) cholangiocarcinoma expressed MMP-7 and MT1-MMP more frequently than papillary cholangiocarcinoma. The expression of MMP-7 and MT1-MMP significantly correlated with the nonpapillary phenotype, poorly differentiated histologic grade, perineural invasion, and advanced TNM stage. In contrast, the expression of MMP-2 and -9 was not associated with any of the clinicopathologic features. Univariate analysis of disease-specific survival revealed that a papillary phenotype and expression of MMP-7 were prognostic factors of cholangiocarcinoma, in addition to TNM stage, poorly differentiated histologic grade, perineural invasion, and microscopic margin status. Multivariate analysis showed only TNM stage to be an independent prognostic factor. Expression of MMP-7 in cholangiocarcinoma is an unfavorable postoperative prognostic factor of cholangiocarcinoma arising from the large bile ducts. Underexpression of MMPs in papillary cholangiocarcinoma might be associated with a favorable prognosis.

Retroperitoneal mucinous cystadenoma: report of two cases and review of the literature.

Primary retroperitoneal cystic tumor is extremely rare, and its histogenesis and biological behavior remain speculative. Two surgical cases of retroperitoneal mucinous cystadenoma (Case 1, an 18-year-old woman; and Case 2, an 85-year-old woman) are reported. The cystadenomas in these cases were mainly lined by a monolayer of columnar or thin flat cells. Case 1 was positive for mucin and epithelial membrane antigen, whereas Case 2 was positive for a mesothelial marker (calretinin). Ciliated epithelium was also interspersed in Case 2. Some parts showed papillary projections, resembling well-differentiated papillary mesothelioma. Within the cyst walls of both cases, ovarian-like stroma that was positive for both estrogen and progesterone receptors was found. Interestingly, focal nodular hyperplasia of the liver was also detected in Case 1. We believe the retroperitoneal mucinous cystadenoma might have arisen from the peritoneum via mucinous epithelial metaplasia with a phenotype of extragenital Mullerian system.