Useful Signs for Lesion Location and Characterization in Uterus – Hyperechoic Line Sign and Feeding Vessel Sign

SECTION 2 – ANSWER Case A 40-year-old female came with a history of abnormal intermenstrual vaginal bleeding for 2 months. She had no pelvic pain or pelvic discharge. She had no comorbidities. Figure 1 shows two useful imaging signs on a transvaginal scan of the uterus. What are the imaging signs shown and the likely diagnosis?Figure 1: High resolution transvaginal ultrasonography sagittal image (a) showing hyperechoic white lines (hyperechoic line sign) representing normal endometrial lining (white arrows), around the hypoechoic intracavitary lesion (black arrow) (b) Power Doppler image of adjacent section showing a single vessel in the center of the endometrial lesion representing the feeding artery or pedicel artery sign (white arrow)INTERPRETATION High-resolution transvaginal ultrasonography sagittal image shows hyperechoic white lines (hyperechoic line sign) representing normal endometrial lining, around the hypoechoic intracavitary lesion. Power Doppler image shows a single vessel in the center of the endometrial lesion, representing the feeding artery or pedicle artery sign [Figure 1]. Magnetic resonance imaging, sagittal and axial image, shows a polypoid T2 intermediate signal lesion in the endometrial cavity with a single feeding central vascular pedicle [Figure 2]. The lesion was reported as an endometrial polyp. The patient chose hysterectomy over transcervical resection of the endometrial polyp, as she was afraid of the very low possibility of malignancy and recurrence. Hysterectomy was done, and histopathological examination revealed a benign endometrial polyp.Figure 2: Magnetic resonance imaging sagittal image (a) and axial image (b) showing a polypoid T2 intermediate signal lesion in the endometrial cavity (black arrows) with a single feeding central vascular pedicle (black arrow)DISCUSSION Hyperechoic line surrounding the central endometrial complex, completely or partially on transvaginal sonography, is known as the “hyperechoic line sign” and is a predictor of focal intracavitary disease [Figure 1].[1] The hyperechoic line represents the thin normal endometrium and the interface between the thin endometrial lining and the intracavitary pathology.[1,2] A hyperechoic line sign may be seen with various focal intracavitary pathologies such as polyps, submucosal fibroids, focal endometrial hyperplasia, and localized neoplasia.[1] Presence of “hyperechoic line sign” has high specificity for focal intracavitary pathologies. Other sonographic findings listed in the table help in differentiating the various endometrial pathologies [Table 1].[1] Presence of cystic spaces or focal vascularity within the central endometrial lesion, in addition to hyperechoic line sign, further enhances the predictive value of focal intracavitary pathology.[1] Endometrial polyps, a common cause of abnormal uterine bleeding, contain a central axis with thick-walled dilated blood vessels, glands, and often fibrous stroma, with the feeding blood vessels visualized on color Doppler called the “pedicle artery sign” or “feeding vessel sign”.[3] Endometrial polyps usually (with a few rare exceptions) show a single pedicle artery with multiple feeding vessels seen in other intracavitary pathology (endometrial hyperplasia/malignancy and submucous myomas).[3-5] Submucous myomas show a circular pattern of blood flow, and endometrial cancer shows multiple irregular feeding vessels.[3] Single feeding vessel (pedicle artery) has a sensitivity of 76.4%, specificity of 95.3%, positive predictive value of 81.3%, and negative predictive value of 91.3% for the diagnosis of polyps.[3] Positive hyperechoic line sign and feeding vessel sign should prompt a hysteroscopic procedure rather than a possibly unsuccessful blind biopsy or saline infusion sonography.Table 1: Differentials for endometrial lesions and their sonographic findingsEthics statement This study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki and its amendments. The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.