:U$ 1ilt射훌훌뿔슐誌 第 25 卷 第 2 號 pp. 326 - 329, 1989 Journal of Korean Radiol앵 ical Soc iety, 25(2) 326 - 329, 1989 Congenital Mesoblastic Nephroma - A Case Report- Dong Ho Lee, M.D., Jae Hooo Lim, M.D., Young Tae Ko, M.D. Department of Radiology, Kyung Hee University Hospital 〈 國文沙錄 〉 先天性 中 R조좋性 賢睡 慶熙大學校 醫科大學 放射線科學敎室 李東鎬·林在勳·高永泰 先天性 中)ff葉性 賢睡은 新生兒 複部睡塊로 냐타냐는 賢藏의 良↑生睡場이 다 . 著者들은 先天性 中 R조葉↑生 賢睡 1 例를 經驗하였기에 報告하고자 한마. 超音波檢훌 및 電算化斷層握影上 境界가 分 明 한 固形睡場으로 內部에 마수의 짧性 壞死을 보였다. - Abstract- Congenital mesoblastic nephroma is a benign renal tumor that appears as a neonatal abdominal mass We have experienced a case of congenital mesoblastic nephroma. The ultrasonographic and CT findings are well-demarcated solid mass containing large portion of cystic necrosis and congenital fibrosarcomaJ). The behavior of this tumor is benign, so complete removal is Introduction cura tIveL2.5\，~) Authors report one patient of congenital meso­ Congenital mesoblastic nephroma is the com­ blastic nephroma with presentation of IVP, ult­ monest neonatal renal neoplasml- 6), and it is alm­ rasonographic, CT and pathologic findings. ost always discovered in the first few months of 4 life2- ). Synonyms for this tumor include fetal re­ Case Report nal hamartoma, leiomyomatous hamartoma, mesenchymal hamartoma of infancy, congenital A 2-month-old boy was referred to our hospital Wilms’ tumor, fibroma, fibromyoma, fibrosarcoma due to abdominal mass . He was born at local clinic with NFSD (normal fullterm spontaneous 이 논문은 1989 년 l 월 1 6 일 접 수하여 19 89 년 2 월 10 일에 채택되었음 delivery)and 3.3 Kg. of body weight. He was seco­ Received ]an.16, Accepted Feb.10, 1989 nd baby. He was well until his mother felt a mass - 326- - Dong Ho Lee , et al.: Cong enital Mesobl asti c Nephrom a- at his right flank area. He had a previous episode of hematuria one month earlier. He was brought to local clinic for treatment of URI 2 days prior to admission. And then he transfered to our hospital. Physical examination revealed firm and hard pa­ lpable mass at right abdomen. IVP film showed a large mass at right kidney with stretched and med­ ially displaced calyx (Fig. 1). Abdominal ultra­ sonography disclosed well-demarcated solid mass nearly occupied the whole right kidney with multi­ focal and interspersed cystic necrosis(Fig. 2). Computed tomography disclosed huge heterogen­ Fig. 2. Ultraso nographic find ing Well 'demarcated solid mass is seen at right eous mass at right kidney and the component of kidney with multifocal so noluce ncies mass was mainly low density. Enhanced calyx was markedly compressed and the remaining renal parenchyme was nearly thinned out(Fig. 3). Right nephrectomy was performed and a 120 gm. renal tumor was removed. Cut section of Fig. 3. CT finding Solid heteroge neo us and mainly low'density mass is see n at right kidney. Enhanced ca. lyx(arrow)i s pos teromedially compressed by tum or gross specimen showed gray-white solid mass, measuring lOx8 cm , with multiple foci of necrosis and hemorrhage. Microscopically, the tumor con­ sisted of interlacing bundles of compact spindle cells with scattered entrapped glomerular struc­ ture(Fig. 4) . The patient has remained well for 10 months after operation. Discussion Fig. 1. IVP finding Congenital mesoblastic nephroma is the comm­ Right calyces(arrow)are stretched, elongated, laterall y comp ressed and med ially di splaced onest neoplasm among renal masses in the first by mass . Hydro nephrosis is ab sent few months of life, although occasionally it may be 327 - - 大韓放射線뿔學會誌 第 25 卷 第 2 號 1989 Hartman et al reported 2 cases with cystic necrosis in total 4 cases, and our case contained large foci of hemorrhage and necrosis 1.5) . Two types of cysts in mass may be explained. One is organization of hemorrhage within the tumor resulting in irregular areas of cystic degeneration. The other cyst is sm­ all fluid-filled , epithelial-lined space, usually 10- cated near the junction of tumor and uninvolved kidney1 .4). Plain films of congenital mesoblastic nephroma usually demonstrate a large soft tissue abdominal mass that is only rarely calcified. Excretory urog­ ram shows a renal mass with marked distortion or compression of the collecting system. Despite of the large size of the tumor, hydronephrosis is of­ ten absent or minimal. Occasionally small accu­ mulations of contrast media are seen within the tumor, resulting of excretion by functioning nep­ hrons trapped within the stroma of the tumor4). Fig. 4. Pathologic finding Ultrasonography usually shows a mixed echogenic a) Gross finding intrarenal mass indistinguishable from Wilms’ tum­ Cut section of mass shows gray-white solid 7 co mponents with extensive hemorrhage and or ) . However the sonographic pattern appears to necrosls be extremely variable running the entire gamut of b) Microscopic findin g The tumor ti ss ues are co nsisted of interlacing echogenicity8). The mass may be echogenic, rela­ 2 bu ndl es of co mpact sp indle cells with scat­ tively hypoechoic, anechoic or mixed echogenic ). tered entrapped glomeruli The sonographic features are similar to that of a noncalcified uterine myoma-a solid mass with low discovered in older children and rarely in level echoes1.3). cr shows a solid intrarenal mass adults 1.3.4) surrounded by a variable amount of functioning The prepartum history is usually unremarkable, renal parenchyme3). Since this neoplasm is usually however, occasionally the pregnancy is complicat­ vascular like leiomyoma, it may show minimal ed by dystocia or polyhydramnios1). The neonate contrast enhancement. usually presents with a large nontender abdominal Microscopically, the tumor consists of interlaci­ 12 mass with no other abnormalities except occas­ ng bundles of benign-appearing spindle cells . ). ionally hematuria3). The mean age at the time of At the renal interface, bundles of spindle cells diagnosis is 3.4 months, and there is a 2:1 male grow between intact nephrons. The central portion predominance3.5). of the tumor is primarily mesenchymal but may The typical tumor is a solid, yellow-tan, unenc­ contain tubules and glomeruli. Since these are sm­ apsulated mass of 8-30 cm , replacing 60 - 90 % of aller than normal or dysplastic, it is uncertain renal parenchyma. The cut surface has a whorled whether they are nephrons that have been trapped appearance resembling a uterine leiomyoma. by the tumor or benign neoplastic differentiation Hemorrhage and necrosis are uncommon, but of the metanephrogεnic blastema1.3). - 328- - Dong Ho Lee , et al.: Congenital Mesoblastic Neph roma- The diseases that must be differentiated from congenital mesoblastic nephroma, are multilocular REFERENCES cyst, multicystic kidney, nephroblastomatosis, neuroblastoma, retroperitoneal hygroma, terato­ 1. Hartman DS , Lesar MSL, Madewell ] E, et al ma, Wilms’ tumor, hepatoblastoma, and infantile M esoblastic nephroma: R adiologic-pathologic cor­ polycystic kidneyl ,2,5,7). Especially it is important relation of 20 cases. A]R 136:69-74, 1981 to distinguish it from Wilms’ tumor because of its 2. Be rd on WE , Wigger H] , Baker DH: Fetal renal benignancy. 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