Real-time tissue elastography of uterine sarcoma

Abstract

Uterine sarcoma is a rare malignant neoplasm associated with a generally poor prognosis, and there is no apparent, sonographic, or diagnostic clue to differentiate uterine sarcoma from uterine leiomyoma [1], although color Doppler ultrasound may help to differentiate between both tumors not only in vessel quantity but also in quality and distribution [2]. Ami et al. [3] reported that real-time tissue elastography is a promising modality to provide detailed mapping and characterization of uterine leiomyoma. We present our first experience of real-time tissue elastography of uterine sarcoma. A 65-year-old Japanese woman was referred to our university hospital because of suspected uterine sarcoma. Transabdominal two-dimensional (2D) sonography showed an enlarged uterus with bizarre, echogenic, and cystic areas (Fig. 1a), and two fibroids. Color Doppler ultrasound depicted increased peripheral and central blood flow in the sarcoma lesion (Figs. 1b, 2a). Transabdominal real-time tissue elastography (Noblus; Hitachi Aloka Medical Ltd., Kashiwa-shi, Chiba, Japan; L34 linear array transabdominal transducer, 3-7 MHz) of the sarcoma revealed a typical mosaic pattern (Figs. 1c, 2b), whereas the fibroid in the anterior uterus was depicted as a predominantly blue tumor (Fig. 2b). The signal intensity score of the sarcoma lesion using ImageJ image analysis software (available at http://rsb.info.nih.gov/ij/) was 88.559 (Fig. 1c), and that of the fibroid was 135.307 (Fig. 1d). Exploratory laparotomy including biopsy of the sarcoma and enucleation of the fibroid in the anterior uterus was carried out for a definitive diagnosis. Final diagnoses were undifferentiated endometrial sarcoma and leiomyoma with calcification. There have been several reports on the elastosonographic imaging of uterine fibroid, adenomyosis, endometrial polyp, cervical cancer, and serous ovarian carcinoma in gynecologic disorders [3–8]. In the present case, real-time tissue elastography showed a typical mosaic pattern in the uterine sarcoma lesion, whereas the fibroid was depicted as a predominantly homogeneous blue tumor. ‘‘The stiffness of the tissue is displayed as a range of colors from red (the softest components) to blue (the hardest components), and the components with average strain are displayed as green’’ [3]. This, to the best of our knowledge, is the first report of uterine sarcoma using real-time tissue elastography as a sonographic adjunct to conventional 2D sonography and color/power Doppler ultrasound. Moreover, the signal intensity of the sarcoma lesion using ImageJ image analysis was low compared to that of the uterine fibroid. Real-time tissue elastography may be a new diagnostic modality for uterine sarcoma. Further studies involving a larger sample size are needed to confirm the potential use of real-time tissue elastography to diagnose uterine sarcoma. E. Nitta K. Kanenishi H. Tanaka T. Hata (&) Department of Perinatology and Gynecology, Kagawa University School of Medicine, 1750-1 Ikenobe, Miki, Kagawa 761-0793, Japan e-mail: toshi28@med.kagawa-u.ac.jp