Prenatal Sonographic and MR Imaging Findings of Extensive Fetal Lymphangioma: A Case Report Sung Eun Rha, MD1 Jae Young Byun, MD1 Hak Hee Kim, MD1, 2 Jong-Chul Shin, MD3 Hyun Young Ahn, MD3 Dong-chul Kim, MD4 Kyo-Young Lee, MD4 Index terms : Fetus, MR Fetus, neoplasms Fetus, US Lymphangioma Korean J Radiol 2003;4:260-263 Received July 22, 2003; accepted after revision November 16, 2003. Department of 1Radiology, The Catholic University of Korea, College of Medicine; 2Department of Radiology, University of Ulsan College of Medicine; Departments of 3Obstetrics and Gynecology and 4Pathology, The Catholic University of Korea, College of Medicine Address reprint requests to: Jae Young Byun, MD, Department of Radiology, Kangnam St. Mary’s Hospital College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul 137-040, Korea. Telephone: (822) 590-2785 Fax: (822) 599-6771 e-mail: jybyun@catholic.ac.kr 260 We report the imaging findings in a case of fetal lymphangioma involving the retroperitoneum and right lower extremity, and diagnosed by ultrasonography and magnetic resonance (MR) imaging at 26 weeks of gestation. Prenatal ultra- sonograms and T2-weighted single-shot fast spin-echo MR images clearly revealed an extensive, multilocular cystic mass with internal hemorrhage in the retroperitoneum extending to the lower extremity. L potential to infiltrate surrounding structures. About 50% are present at ymphangiomas are hamartomas of the lymphatic vessels that have the birth and up to 90% become evident by the age of two years (1). The prognosis of a lymphangioma depends on the location and extent of the lesion and the presence of other associated abnormalities. Because fetal lymphangiomas are frequent- ly associated with karyotypic or other abnormalities, including skin edema, hydrops fetalis, and polyhydramnios, their prenatal diagnosis is important. The neonatal out- come of a large fetal lymphangioma is generally poor (2). Although spontaneous re- gression can occur in a fetal lymphangioma with normal chromosomes, large fetal lym- phangiomas require a perinatal team approach, with possible management options in- cluding prenatal aspiration of the cyst, elective cesarean section, or a delivery mode which will avoid fetal damage (3). Prenatal diagnosis thus permits a planned delivery, and adequate intrapartum and postnatal resuscitation may improve the prognosis. Several case reports regarding the prenatal sonographic findings of fetal abdominal lymphangioma have been published (2), but to the best of our knowledge, only two reports have described the magnetic resonance (MR) imaging finding (4, 5). We report the imaging findings in a case of extensive fetal lymphangioma involving the right side of the retroperitoneum and extending to the right thigh and lower leg, which was cor- rectly diagnosed by sonography and confirmed by MR imaging at 26 weeks of gesta- tion. CASE REPORT A 34-year-old woman whose one previous pregnancy had involved cesarian section and the delivery of a healthy male infant at term was referred to our hospital at 26 weeks of gestation on account of earlier sonographic findings which had indicated pos- sible multicystic dysplastic kidney and sacrococcygeal teratoma. Detailed sonography revealed the presence of a large, multiseptated cystic mass at the right side of the ab- domen, extending to the right buttock and lower extremity, the transverse diameter of which was much larger than that of the left (Fig. 1A). The mass demonstrated variable echo patterns; color Doppler sonography revealed no internal flow at the time of ex- Korean J Radiol 4(4), December 2003