Posterior choroidal leiomyoma: new findings from a case and literature review

·Posterior choroidal leiomyoma is a sporadic, rare benign tumor that is always confused with anaplastic melanoma. Here we report a case and provide a review. Most of the preoperative findings in our case were suggestive of malignant choroidal melanoma. However, the contrast enhanced ultrasound(CEUS) suggested a benign hemangioma. In summary, the posterior choroidal leiomyomas were yellowish-white in color and most commonly located in the temporal quadrant of the fundus(11/15). They were more frequent in Asians(13/16), the prevalence was almost equal in males and females(9:7), with a mean age of 35y. Microscopically, the tumor typically showed spindle cell bundles and nonmitotic ovoid nuclei arranged in intersecting fascicles. Vitrectomy is now a popular treatment option and definitive diagnosis can be made after immunohistochemistry. Finally, some summarized features of this tumor differ from those previously described. These may help in the diagnosis of posterior choroidal leiomyoma and differentiation from malignant melanoma.

High mechanical index post-contrast ultrasonography improves tissue structural display of hepatocellular carcinoma

Background The advent of second generation agent-SonoVue and low mechanical index real-time contrast enhanced ultrasonography （CEUS） imaging have been shown to improve the diagnostic performance of uhrasonography in hepatocellular carcinoma （HCC）. But no report has described the effect of high mechanical index （MI） post-CEUS. This study aimed to investigate the value of post-CEUS in displaying tissue structures of HCC. Methods Seventy-six HCCs in 65 patients were included in the study. Each patient underwent three scans, high-MI （ MI ： 0. 15 - 1.6 ） pre-contrast ultrasound, low-MI （ MI ： 0. 04 - 0. 08 ） CEUS with contrast agent SonoVue, and high-MI post-contrast ultrasound, which was performed within 3 minutes after CEUS. The size, boundary, echogenicity, internal echotexture and posterior acoustic enhancement of the HCCs in the conventional scans before and after CEUS were evaluated. According to pathological evidence, diagnosis rates of pre-contrast, CEUS and post-contrast scans were determined and compared. The potential mechanism of post-contrast ultrasound imaging was also discussed. Results Compared with pre-contrast, post-contrast ultrasound showed improvement in image quality in most HCCs： twenty-six （34. 2% ） more lesions showed well defined margins and fourteen （18.4%） more nodules showed halo sign; twenty-three （30. 3% ） lesions demonstrated enlarged in sizes; changes in echogenicity were seen in 30 lesions （39.5%） ; eighteen （23.7%） more lesions showed heterogenecity and 20 （26. 3% ） more lesions showed “mosaic”or “nodule-in-nodule” sign; twelve （15.8%） more lesions showed posterior acoustic enhancement. Post-contrast ultrasound showed increased diagnostic accuracy of 93.4% （71/76）, compare with 88.2% （67/76） of CEUS alone. Conclusions High-MI post-contrast ultrasound utilizes harmonic signals during the rupture of microbubbles, and significantly improves the display of echo-characteristics of HCCs in ultrasound images, which adds diagnostic values for CEUS. Post-contrast ultrasound could play an important role in tissue characterization, and may be included in CEUS protocols.