K. Konno

Portal vein aneurysm: report of six cases and review of the literature

Abstract. Portal vein aneurysm is very rare, and its relation to portal hypertension has been emphasized. We report six cases of portal vein aneurysm (five extrahepatic and one intrahepatic). All patients were asymptomatic and had no signs suggestive of portal hypertension; the lesion was incidentally detected by ultrasound. Color Doppler sonography showed a constant hepatopetal flow along the aneurysmal wall, which immediately led to the diagnosis. We stress the usefulness of color Doppler sonography for studying the hemodynamics of this vascular anomaly and briefly review the literature.

Splenic lymphangioma : US and CT diagnosis and clinical manifestations

AbstractBackground and methods: We tried to determine the role and problems of gray-scale sonography (US), computed tomography (CT), and color Doppler sonography in the diagnosis of splenic lymphangioma on the basis of our experience with seven adult cases with this relatively rare tumor. Results: (1) The whole spleen was replaced by a collection of cysts of different sizes with or without calcifications in six patients. In these patients, color Doppler sonography showed the intrasplenic arteries and veins running along the cyst walls. (2) The enlarged spleen occupied the whole upper abdomen and contained numerous small cysts in one patient. The patient was initially diagnosed as having a pancreatic tumor because of the location, but color Doppler sonography clearly demonstrated two vessels (artery and vein) running parallel from the center of the mass. This characteristic vascular structure led to the determination that the mass was the markedly enlarged spleen. (3) The splenic lesion was isolated in six patients but was associated with mesenteric and pleural lymphangioma in one symptomatic patient. Conclusions: (1) When US shows multiple cysts of different sizes in the spleen, the diagnosis of splenic lymphangioma is not difficult to make with US and CT alone. (2) Color Doppler sonography is a very useful tool to increase diagnostic confidence because it demonstrates the vasculature of the mass. (3) When examining patients with splenic lymphangioma, one should consider the possibility of multiorgan involvement.

Appendiceal mucocele: sonographic findings.

AbstractBackground: Appendiceal mucocele (AM) is a relatively rare disease, and its sonograms (US) have not been sufficiently analyzed. Methods: We studied the US findings of five patients with AM, with special attention to AM size, shape, internal echoes, and the mode of back echoes. Results: All five cases showed an elongated mass in the lower right abdomen. Internal echoes were present in all cases and M-mode US confirmed the movement of those echoes. The echogenecity of the lesion changed according to the frequency of the transducer used. Only one case showed posterior echo enhancement, and no case showed lateral shadowing. Conclusion: AM appears as an elongated echo-poor mass without posterior echo enhancement. The cyst wall is less distinct than what one would expect for a cyst. When encountering such a mass in the lower right abdomen, one should strongly suspect an AM. In such cases, appropriate diagnostic and therapeutic strategies are especially necessary to prevent rupture that results in development of pseudomyxoma peritonei.

Gallbladder carcinoma: color Doppler sonography

This study, based on color Doppler and pulsed Doppler sonographic results of 13 cases with gallbladder carcinoma, eight cases of adenomyomatosis, and eight cases of tumefactive biliary sludge, shows that the presence or absence of blood flow signals helps in the differentiation between gallbladder carcinoma and tumefactive biliary sludge (84.6% sensitivity and 80.0% specificity). However, color Doppler sonography is still not fully capable of distinguishing all gallbladder carcinoma, and a further increase in Doppler sensitivity is mandatory for this purpose. Visualization of high-velocity blood flow within the lesion made gallbladder carcinoma more likely than benign tumor. In contrast, there was no difference in the resistive index between gallbladder carcinoma, adenomyomatosis, and normal subject groups, and the significance of the resistive index is a subject of future study.

Mesenteric cyst: sonographic findings

AbstractBackground: Mesenteric cyst (MC) is a relatively rare disease, and its sonographic characteristics have not been sufficiently analyzed. Methods: We studied the sonographic findings of eight patients with MC, with attention paid to its size, shape, internal echoes, and especially the presence or absence of lateral shadowing and the mode of back echoes. In four cases, the sound velocity and acoustic impedance of cystic fluid were also measured. The mode of blood flow was evaluated by color Doppler sonography. Results: Six cases showed an oval or comma-shaped mass. Internal echoes were present in six cases, and two of them showed a pseudosolid pattern. In these cases, M-mode sonography confirmed the movement of these internal echoes. Only one case showed a posterior echo enhancement, and no case showed lateral shadowing. Sound velocity measured in four cases was 1515–1537 m/s, with an acoustic impedance of 1.550–1.576 kg/m2/s. No blood flow signals were obtained from the lesion. Conclusion: MC exhibits so many patterns on ultrasound that we should consider the possibility of MC when encountering an avascular oval mesenteric mass.

Mesenteric lipoma: report of a case with emphasis on US findings

Abstract. Mesenteric lipoma (ML) is a relatively rare disease that has been very infrequently reported. We present the clinical data and medical imaging results of an asymptomatic case with ML incidentally detected by sonography (US). On US the lesion was imaged as a well-demarcated hypoechoic mass with multiple linear echoes. The mass also changed location under probe compression. The lesion was imaged as a clearly demarcated non-enhanced homogeneous fat-density mass on CT. Color Doppler US and angiography confirmed the avascular nature of the mass. Knowledge of the US findings in this case is useful for the diagnosis of ML.

Renal arteriovenous malformation: sonographic findings.

AbstractBackground and Methods: Renal arteriovenous malformation (RAVM) is a relatively rare congenital disease. Although sonography (US) currently is the first diagnostic tool for examining the kidney, its US and color Doppler findings have seldom been reported. We reviewed the clinical manifestations and US results of five cases of RAVM to clarify the role and limitations of US in the diagnosis. Results: The lesions were solitary in all cases, and the affected side was the right in four cases and the left in one case. In four cases, the patients complained of hematuria, but the remaining case had no symptoms. US did not detect the lesion, but in all cases color Doppler US showed a focal vascular lesion with posterior color spots. US reexamination with knowledge of the Doppler results did not show any focal lesion. Conclusion: US was not diagnostic for RAVM, and color Doppler US should be performed immediately in patients with hematuria.

Adenosquamous carcinoma of the pancreas: report of two cases

Adenosquamous carcinoma (ASqC) of the pancreas is a rare tumor. We analyzed the radiologic findings and clinical manifestations in two such cases. In both cases (a 51-year-old woman and a 67-year-old man), the portal system was selectively and largely invaded, the superior mesenteric vein in one and the splenic vein in the other, without arterial invasion. Thus, peripancreatic vessels should be carefully observed in patients with ASqC of the pancreas. One case showed an unusual mode of spread. Only a huge metastatic lesion was initially detected, leading to the misdiagnosis of primary malignant mesenteric tumor. Such an unusual growth pattern is also worth noting.

Chilaiditi syndrome: sonographic findings

AbstractBackground and methods: Sonographic (US) findings of Chilaiditi syndrome have been rarely reported in the literature. We reviewed 18 cases of Chilaiditi syndrome to pinpoint its US pattern. Results: (1) US showed gas echoes of different sizes superimposed over the entire liver in two cases and over the right hepatic lobe in six cases, leading to a high suspicion of Chilaiditi syndrome. (2) US showed a small gas echo in the hepatodiaphragmatic space, mimicking pneumoperitoneum in eight cases. In this instance, altering the patients position allowed for confirmation of the lack of a change in the location of the gas echo, unlike cases of pneumoperitoneum. (3) The hepatic surface appeared as a hyperechoic mass in two cases. Conclusion: Knowledge of US patterns of Chilaiditi syndrome helps avoid confusion with pneumoperitoneum or hepatic masses.

Color Doppler findings in Castleman's disease of the mesentery

Castlemans disease is a relatively rare lymphoproliferative disease. We report an asymptomatic case of Castlemans disease isolated to the mesentery and detected incidentally by sonography. In this case, color Doppler sonography demonstrated an artery penetrating the masss hilum, suggesting a lymphatic origin of the lesion, as well as fine accessory peripheral arteries, suggesting malignancy. To our knowledge, there has been no previous report of detailed color Doppler findings in Castlemans disease.