Appendiceal Mucinous Neoplasm Detected due to the Protrusion of Mucin, in the Absence of Appendiceal Distension: A Case Report / 대한소화기암학회지

A mucocele is a cystic dilatation of the vermiform appendix that contains mucous material. The symptoms associated with it are not specific and the diagnosis is seldom made prior to surgery. The reported prevalence in appendectomy specimens procured during surgery is 0.2-0.3%. Recently, we experienced a case of patient with appendiceal mucocele detected by colonoscopic examination. This case did not show typical colonoscopic features of a mucocele, demonstrating protrusion of mucin, in the absence of a smooth mound with normal overlying mucosa surrounding the appendiceal orifice. The case involved a 64-year-old woman who underwent a colonoscopy. An abdominopelvic computed tomography scan suggested a normal appendix. Subsequently, we performed an appendectomy. The pathologic finding was a low-grade appendiceal mucinous neoplasm.

Appendiceal Mucinous Neoplasm Detected due to the Protrusion of Mucin, in the Absence of Appendiceal Distension: A Case Report / 대한소화기암학회지

A mucocele is a cystic dilatation of the vermiform appendix that contains mucous material. The symptoms associated with it are not specific and the diagnosis is seldom made prior to surgery. The reported prevalence in appendectomy specimens procured during surgery is 0.2-0.3%. Recently, we experienced a case of patient with appendiceal mucocele detected by colonoscopic examination. This case did not show typical colonoscopic features of a mucocele, demonstrating protrusion of mucin, in the absence of a smooth mound with normal overlying mucosa surrounding the appendiceal orifice. The case involved a 64-year-old woman who underwent a colonoscopy. An abdominopelvic computed tomography scan suggested a normal appendix. Subsequently, we performed an appendectomy. The pathologic finding was a low-grade appendiceal mucinous neoplasm.

Non-hypervascular Hypointense Nodules on Hepatocyte Phase Gadoxetic Acid-Enhanced MR Images: Transformation of MR Hepatobiliary Hypointense Nodules into Hypervascular Hepatocellular Carcinomas

BACKGROUND/AIMS: The annual risk of transformation of non-hypervascular magnetic resonance (MR) hepatobiliary phase imaging (HBPI) hypointense nodules into hypervascular hepatocellular carcinomas (HCCs) was evaluated. METHODS: Cirrhotic patients with non-hypervascular HBPI hypointense nodules were retrospectively analyzed if they were diagnosed as HCC and MR followed up longer than 1 year during the period from January 2010 to October 2016 with regular intervals of 3 to 6 months. Risk factors for transformation into hypervascular HCCs were analyzed using the Cox proportional hazard model. RESULTS: Among the 103 non-hypervascular HBPI hypointense nodules meeting the inclusion criteria, transformation into hypervascular HCCs occurred in 44 tumors (42.7%). The median follow-up period was 24 months. Multivariate analysis revealed that hyperintensity on T2-weighted images (T2WI) and diffusion-weighted images (DWI) were the two independent predictors of transformation into hypervascular HCCs (p=0.036 and p=0.041, respectively). Most tumors with hyperintensity on T2WI or DWI on the initial or follow-up MR were transformed into hypervascular HCCs within the first year. Among the 22 nodules (21.3%) showing a new change in dynamic phases during follow-up, 14 nodules (13.6%) showed malignant transformations. CONCLUSIONS: The transformation rates of HBPI hypointense nodules into hypervascular HCCs could be predicted according to the initial or serial MRI findings.

Correlations of Dynamic Contrast-Enhanced Magnetic Resonance Imaging with Morphologic, Angiogenic, and Molecular Prognostic Factors in Rectal Cancer

PURPOSE: To investigate the correlations between parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and prognostic factors in rectal cancer. MATERIALS AND METHODS: We studied 29 patients with rectal cancer who underwent gadolinium contrast-enhanced, T1-weighted DCE-MRI with a three Tesla scanner prior to surgery. Signal intensity on DCE-MRI was independently measured by two observers to examine reproducibility. A time-signal intensity curve was generated, from which four semiquantitative parameters were calculated: steepest slope (SLP), time to peak (Tp), relative enhancement during a rapid rise (Erise), and maximal enhancement (Emax). Morphologic prognostic factors including T stage, N stage, and histologic grade were identified. Tumor angiogenesis was evaluated in terms of microvessel count (MVC) and microvessel area (MVA) by morphometric study. As molecular factors, the mutation status of the K-ras oncogene and microsatellite instability were assessed. DCE-MRI parameters were correlated with each prognostic factor using bivariate correlation analysis. A p-value of <0.05 was considered significant. RESULTS: Erise was significantly correlated with N stage (r=-0.387 and -0.393, respectively, for two independent data), and Tp was significantly correlated with histologic grade (r=0.466 and 0.489, respectively). MVA was significantly correlated with SLP (r=-0.532 and -0.535, respectively) and Erise (r=-0.511 and -0.446, respectively). MVC was significantly correlated with Emax (r=-0.435 and -0.386, respectively). No significant correlations were found between DCE-MRI parameters and T stage, K-ras mutation, or microsatellite instability. CONCLUSION: DCE-MRI may provide useful prognostic information in terms of histologic differentiation and angiogenesis in rectal cancer.

Detection of Hepatic Lesion: Comparison of Free-Breathing and Respiratory-Triggered Diffusion-Weighted MR imaging on 1.5-T MR system

PURPOSE: To compare free-breathing and respiratory-triggered diffusion-weighted imaging on 1.5-T MR system in the detection of hepatic lesions. MATERIALS AND METHODS: This single-institution study was approved by our institutional review board. Forty-seven patients (mean 57.9 year; M:F = 25:22) underwent hepatic MR imaging on 1.5-T MR system using both free-breathing and respiratory-triggered diffusion-weighted imaging (DWI) at a single examination. Two radiologists retrospectively reviewed respiratory-triggered and free-breathing sets (B50, B400, B800 diffusion weighted images and ADC map) in random order with a time interval of 2 weeks. Liver SNR and lesion-to-liver CNR of DWI were calculated measuring ROI. RESULTS: Total of 62 lesions (53 benign, 9 malignant) that included 32 cysts, 13 hemangiomas, 7 hepatocellular carcinomas (HCCs), 5 eosinophilic infiltration, 2 metastases, 1 eosinophilic abscess, focal nodular hyperplasia, and pseudolipoma of Glisson's capsule were reviewed by two reviewers. Though not reaching statistical significance, the overall lesion sensitivities were increased in respiratory-triggered DWI [reviewer1: reviewer2, 47/62(75.81%):45/62(72.58%)] than free-breathing DWI [44/62(70.97%):41/62(66.13%)]. Especially for smaller than 1 cm hepatic lesions, sensitivity of respiratory-triggered DWI [24/30(80%):21/30(70%)] was superior to free-breathing DWI [17/30(56.7%):15/30(50%)]. The diagnostic accuracy measuring the area under the ROC curve (Az value) of free-breathing and respiratory-triggered DWI was not statistically different. Liver SNR and lesion-to-liver CNR of respiratorytriggered DWI (87.6+/-41.4, 41.2+/-62.5) were higher than free-breathing DWI (38.8+/-13.6, 24.8+/-36.8) (p value <0.001, respectively). CONCLUSION: Respiratory-triggered diffusion-weighted MR imaging seemed to be better than free-breathing diffusion-weighted MR imaging on 1.5-T MR system for the detection of smaller than 1 cm lesions by providing high SNR and CNR.

Detection of Hepatic Lesion: Comparison of Free-Breathing and Respiratory-Triggered Diffusion-Weighted MR imaging on 1.5-T MR system

PURPOSE: To compare free-breathing and respiratory-triggered diffusion-weighted imaging on 1.5-T MR system in the detection of hepatic lesions. MATERIALS AND METHODS: This single-institution study was approved by our institutional review board. Forty-seven patients (mean 57.9 year; M:F = 25:22) underwent hepatic MR imaging on 1.5-T MR system using both free-breathing and respiratory-triggered diffusion-weighted imaging (DWI) at a single examination. Two radiologists retrospectively reviewed respiratory-triggered and free-breathing sets (B50, B400, B800 diffusion weighted images and ADC map) in random order with a time interval of 2 weeks. Liver SNR and lesion-to-liver CNR of DWI were calculated measuring ROI. RESULTS: Total of 62 lesions (53 benign, 9 malignant) that included 32 cysts, 13 hemangiomas, 7 hepatocellular carcinomas (HCCs), 5 eosinophilic infiltration, 2 metastases, 1 eosinophilic abscess, focal nodular hyperplasia, and pseudolipoma of Glisson's capsule were reviewed by two reviewers. Though not reaching statistical significance, the overall lesion sensitivities were increased in respiratory-triggered DWI [reviewer1: reviewer2, 47/62(75.81%):45/62(72.58%)] than free-breathing DWI [44/62(70.97%):41/62(66.13%)]. Especially for smaller than 1 cm hepatic lesions, sensitivity of respiratory-triggered DWI [24/30(80%):21/30(70%)] was superior to free-breathing DWI [17/30(56.7%):15/30(50%)]. The diagnostic accuracy measuring the area under the ROC curve (Az value) of free-breathing and respiratory-triggered DWI was not statistically different. Liver SNR and lesion-to-liver CNR of respiratorytriggered DWI (87.6+/-41.4, 41.2+/-62.5) were higher than free-breathing DWI (38.8+/-13.6, 24.8+/-36.8) (p value <0.001, respectively). CONCLUSION: Respiratory-triggered diffusion-weighted MR imaging seemed to be better than free-breathing diffusion-weighted MR imaging on 1.5-T MR system for the detection of smaller than 1 cm lesions by providing high SNR and CNR.

Leiomyosarcoma of the Ovarian Vein: a Case Report with Radiological Findings

Leiomyosarcomas of the ovarian vein are very rare. Four cases have been reported in the English language clinical literature. We present a case of leiomyosarcomas where the use of multi-detector CT had a substantial role in the establishment of the preoperative diagnosis. The radiological images as well as intraoperative features are illustrated. We also discuss the radiological findings of the ovarian vein leiomyosarcoma in comparison with those of other venous or retroperitoneal leiomyosarcomas. We expect that the use of multi-detector CT will be the choice for the diagnostic work-up of vascular leiomyosarcomas.