Contrast-enhanced ultrasound imaging characteristics of malignant transformation of a localized type gallbladder adenomyomatosis: A case report and literature review.

Gallbladder adenomyomatosis (GAM) is an acquired, reactive, tumor-like condition. Malignant transformation is extremely rare, and imaging features during contrast-enhanced ultrasound (CEUS) have not been described before. Herein, we describe a 73-year-old Asian man who had been diagnosed with gallbladder carcinoma by conventional ultrasonography (US). Based on additional radiological findings, we believed that it was a localized adenomyomatosis. However, the histopathological diagnosis was adenocarcinoma originate from adenomyomatosis with serosal invasion. We believe this is the first case of adenocarcinoma derived from GAM with characteristics of CEUS findings. This case is presented to indicate a clinical awareness of malignant transformation of GAM and discuss the radiology significance with an emphasis on CEUS.

Differential diagnosis of gallbladder wall thickening: the usefulness of contrast-enhanced ultrasound.

he purpose of this study was to evaluate the usefulness of contrast-enhanced ultrasound (CEUS) in the differential diagnosis of gallbladder wall (GBW) thickening and determine the predictors of malignant GBW thickening. One hundred fifty-nine patients with GBW thickening, including 76 men and 83 women, from eight institutions were enrolled. CEUS was performed after injection of a sulfur hexafluoride microbubble-based ultrasound contrast agent. Multiple logistic regression analysis was used to reveal independent predictor sassociated with malignant GBW thickening. The final diagnoses were 48 gallbladder carcinomas and 111 benign gallbladder diseases.Maximal thicknesses of the GBW in malignant and benign GB Wthickening were 17.3 ± 5.2 (6 ­ 30) mm and 8.6 ± 5.1 (4 ­ 26) mm respectively (p , 0.001). CEUS revealed significant differences in intralesional vessels, enhancement homogeneity, time to hypo-enhancement, inner layer discontinuity, outer layer discontinuity and adjacent liver involvement (all p-values , 0.05) between malignant and benign GBW thickening. Patient age . 46.5 y, focal GBW thickening, inner layer discontinuity and outer layer discontinuity were found to be associated with malignancy by multiple logistic regression analysis (all p-values , 0.05). Receiver operating characteristic curve analysis revealed Az values for patient age, focal GBW thickening, inner wall discontinuity and outer wall discontinuity of 0.709 (95%confidence interval [CI]: 0.627­0.790), 0.714 (95% CI: 0.630­0.798), 0.860 (95%CI: 0.791 ­ 0.928) and 0.858 (95% CI: 0.783 ­ 0.933), respectively. CEUS is useful in the differential diagnosis between malignant and benign GBW thickening. Focal GBW thickening, inner wall discontinuity and outer wall discontinuity observed on CEUS are diagnostic clues for malignant GBW thickening.

Diagnosis of pyriform sinus fistula in children via ultrasonography.

A pyriform sinus fistula is a rare congenital abnormality of the third or fourth branchial pouch that usually affects children. We report one case of the condition; ultrasound (US) imaged a heterogeneous mass with a hypoechoic area and air bubbles representing an abscess. Although these manifestations are rare, prominent and characteristic findings on US may facilitate the diagnosis of pyriform sinus fistula.

Contrast-enhanced ultrasound versus conventional ultrasound in the diagnosis of polypoid lesion of gallbladder: a multi-center study of dynamic microvascularization.

OBJECTIVE: To assess the value of contrast-enhanced ultrasound (CEUS) in the diagnosis of polypoid lesions of gallbladder (PLGs). METHODS: CEUS was performed to 116 patients (mean age, 49.6 years; range, 21-80 years) with PLGs from 8 university hospitals. 9 cases of biliary sludge were proven by surgery and the remaining 107 cases were confirmed by histopathological examination. The confidence level, diagnostic performance, inter-observer agreement of two independent readers with different experience was assessed. The readers were blind to the imaging and clinical results of the patients. RESULTS: There were significant differences between benign and malignant PLGs in patient age, gender, lesion size, echogenicity, stalk, time-to-peak, vascularity on CEUS, enhancement pattern, and wall destruction. The confidence levels increased significantly and the interobserver agreement increased from 0.425 to 0.601 after CEUS. The sensitivity increased from 22.2 to 77.8% after CEUS in the staff radiologist, and from 22.2 to 66.7% in the resident radiologist. The correctly characterized lesions were 64.7% before versus 87.1% after CEUS (P=0.125) for the staff radiologist, and 57.8% versus 70.7% for the resident radiologist (P=0.007). No significance was found in the subgroup of lesions≤1.0 cm before and after CEUS for the two radiologists. CONCLUSIONS: CEUS using convex multifrequency probes could detect the dynamic microvascularization of PLGs greater than 1.0 cm and facilitate the differentiation between benign and malignant tumors.

Contrast-enhanced ultrasound in the diagnosis of gallbladder diseases: a multi-center experience.

OBJECTIVE: To assess the usefulness of contrast-enhanced ultrasound (CEUS) in differentiating malignant from benign gallbladder (GB) diseases. METHODS: This study had institutional review board approval. 192 patients with GB diseases from 9 university hospitals were studied. After intravenous bonus injection of a phospholipid-stabilized shell microbubble contrast agent, lesions were scanned with low acoustic power CEUS. A multiple logistic regression analysis was performed to identify diagnostic clues from 17 independent variables that enabled differentiation between malignant and benign GB diseases. Receiver operating characteristic (ROC) curve analysis was performed. RESULTS: Among the 17 independent variables, multiple logistic regression analysis showed that the following 4 independent variables were associated with the benign nature of the GB diseases, including the patient age, intralesional blood vessel depicted on CEUS, contrast washout time, and wall intactness depicted on CEUS (all P<0.05). ROC analysis showed that the patient age, intralesional vessels on CEUS, and the intactness of the GB wall depicted on CEUS yielded an area under the ROC curve (Az) greater than 0.8 in each and Az for the combination of the 4 significant independent variables was 0.915 [95% confidence interval (CI): 0.857-0.974]. The corresponding Az, sensitivity, and specificity for the age were 0.805 (95% CI: 0.746-0.863), 92.2%%, and 59.6%; for the intralesional vessels on CEUS were 0.813 (95% CI: 0.751-0.875), 59.8%, and 98.0%; and for the GB wall intactness were 0.857 (95% CI: 0.786-0.928), 78.4%, and 92.9%. The cut-off values for benign GB diseases were patient age <53.5 yrs, dotted intralesional vessels on CEUS and intact GB wall on CEUS. CONCLUSION: CEUS is valuable in differentiating malignant from benign GB diseases. Branched or linear intralesional vessels and destruction of GB wall on CEUS are the CEUS features highly suggestive of GB malignancy and the patient age >53.5 yrs is also a clue for GB malignancy.

Contrast-enhanced sonographic appearance of malignant fibrous histiocytoma in the sigmoid colon: a case report.

Malignant fibrous histiocytoma (MFH) of the sigmoid colon is extremely rare and imaging characteristics of MFH during contrast-enhanced sonography have not been described yet. Here we report the case of a 55-year-old man suffering from MFH in the sigmoid colon, with an emphasis on contrast-enhanced sonography findings.

Solid pseudopapillary tumors of the pancreas: contrast-enhanced sonographic features.

OBJECTIVES: The aims of this study were to determine the features of solid pseudopapillary tumors of the pancreas on contrast-enhanced sonography and correlate them with pathologic findings. METHODS: Five patients with solid pseudopapillary tumors of the pancreas underwent conventional sonographic, color Doppler flow imaging, and contrast-enhanced sonographic examinations. Time-intensity curves were used to calculate the contrast enhancement times, wash-out times, and enhancement patterns of the lesions. Three of the 5 patients also underwent contrast-enhanced computed tomography. All cases were confirmed by surgery and pathologic examination. RESULTS: The study included 3 women and 2 men. Tumor diameters ranged from 4.4 to 13.0 cm. Sonography revealed round well-defined encapsulated tumors. Two appeared as mixed cystic-solid and 3 as solid masses on conventional sonography. One mass had a macrocalcification. Some areas of blood flow were seen in 3 of the masses on color Doppler flow imaging. On contrast-enhanced sonography, the peripheral rims of the tumors showed isoenhancement during the early arterial phase, and the interiors of the masses showed heterogeneous enhancement consisting of regions of isoenhancement, hypoenhancement, and nonenhancement. Progressive wash-out of the contrast agent during venous phases revealed hypoenhancement compared with normal adjacent pancreatic parenchyma. Pathologic findings showed that each tumor was completely encapsulated and had varying degrees of internal hemorrhage and necrosis. CONCLUSIONS: Solid pseudopapillary tumors of the pancreas have characteristic findings on contrast-enhanced sonography, including peripheral rim isoenhancement and internal heterogeneous enhancement with nonenhanced portions; these features may help differentiate solid pseudopapillary tumors from other pancreatic neoplasms.

Cystic lymphangioma of the pancreas with congenital intrahepatic duct dilatation and choledochal cyst.

Cystic lymphangioma of the pancreas is an extremely rare benign tumor of lymphatic origin. We report on a 68-year-old woman who had experienced epigastric abdominal distension and nausea for over 1 year. Sonography revealed a cystic-solid mixed mass in the head of pancreas, with intrahepatic and extrahepatic duct dilatation. A diagnosis of cystic lymphangioma with congenital intrahepatic duct dilatation and choledochal cyst was made after excision and pathologic examination. Preoperative diagnosis of cystic lymphangioma of the pancreas is difficult, and carefulsonographic evaluation is required.

Signet-ring cell carcinoma of ampulla of Vater: contrast-enhanced ultrasound findings.

Signet-ring cell carcinoma (SRCC) of ampulla of Vater is extremely uncommon, and less than 15 cases have been reported so far in literature. It mainly occurs in elderly people (median age 57 years). We report a rare case of SRCC of the ampulla of Vater in a 38-year-old woman who presented with a small tumor at the Vater, discovered by the contrast-enhanced ultrasound (CEUS). Histopathological examination showed prominent signet-ring features. We also describe the imaging features of SRCC of ampulla of Vater in CEUS.