일차성간림프종 : 자기공명영상과병리소견의연관 김한나 1 신유리 1 나성은 1 정은선 2 오순남 1 최준일 1 정승은 1 이영준 1 일차성간림프종은전체림프절외장기를침범하는림프종의 1% 미만에서나타나는매우드문질환이다. 저자들은수술로확진된일차성간림프종의자기공명영상과병리소견의특징을보고한다. 간세포특이조영제를주입하여얻은역동적조영증강영상에서점차적으로조영증강되어간내담관암과유사하게보였다. 그러나 20분지연후얻은간담관기영상과확산강조영상에서서로다른신호강도를보이는세층의띠모양의병변이특징적으로보였으며이는병리적으로외층의생존종양, 중간층의괴사된종양, 및종양에둘러싸인중앙부의괴사된간실질과일치되는소견을보였다. 서 론 증례보고 일차성간림프종은비장, 림프절, 골수또는다른림프조직을침범하지않고, 간에국한되어있는림프종으로정의할수있다 (1). 간은진행된비호지킨림프종환자에서흔히침범하는림프절외장기의하나이지만대부분이차성간림프종이며, 일차성간림프종은매우드물다. 간림프종의영상진단은, 이차성인경우동반된다른소견과함께고려할때비교적쉽게진단할수있으나, 일차성의경우그다양한발현양상과드문빈도로인해영상소견이잘정리되어보고되지않아영상진단에어려움을겪는경우가흔하다 (2, 3). 일차성간림프종의자기공명영상소견은거의보고되지않았는데, 저자들은최근단일종괴로발현하였으며간표면위축을동반하였고, 역동적조영증강소견등을고려할때간내담관암을의심할수있었던일차성간림프종을경험하였다. 특히본증례에서는간세포특이조영제를이용한자기공명영상및확산강조자기공명영상에서림프종의병리소견을잘설명할수있는특징적인영상소견을확인할수있었기에이를보고하고자한다. 78세남자환자가 2개월간의우상복부통증으로입원하였다. 환자는체중감소나야간발한등은없었다. 환자는과거력에서특이소견이나간경변을시사하는소견은없었으며비장이나림프절이촉지되지않았다. 혈액검사결과는젖산탈수소효소가경미하게증가된것이외에정상이었고혈청검사결과 A형, B형그리고 C형간염검사가모두음성이었으며태아성암항원 (CEA), 알파태아단백 (alpha-fetoprotein), 당쇄항원 19-9(CA 19-9) 를포함한종양표지검사도모두정상범위였다. 복부초음파검사에서는간에크기약 6 cm의크고불균질한에코를보이는종괴가보였다. 역동적조영증강전산화단층촬영에서는큰고형의저감쇠를보이는종괴가간좌엽에있고동맥기와문맥기에서는주변부가조영증강되고평형기로갈수록중심부에점차조영증강이되는양상을보였다. 간피막의퇴축이동반되어있었다. 자기공명영상 (Achieva 1.5T, Philips medical systems, Best, The Netherlands) 에서는간좌엽에분엽상의큰종괴가보이고간원삭틈새와좌문맥의배꼽분절을둘러싸고있으나종괴에의한간문맥과간원삭틈새의폐쇄는보이 대한자기공명의과학회지 14:151-155(2010) 1 가톨릭대학교의과대학방사선과학교실서울성모병원영상의학과 2 가톨릭대학교의과대학병원병리학교실서울성모병원접수 : 2010 년 10 월 5 일, 수정 : 2010 년 10 월 10 일, 채택 : 2010 년 10 월 14 일통신저자 : 신유리, (137-701) 서울특별시서초구반포동 505 번지, 가톨릭대학교의과대학방사선과학교실서울성모병원영상의학과 Tel. (02) 2258-1455 Fax. (02) 599-6771 E-mail: crystal57@catholic.ac.kr - 151-
김한나외 a b c d Fig. 1. A 78-year-old man with primary hepatic lymphoma. (a) Axial fat suppressed T2-weighted fast spin echo image shows a large lobulated hyperintense mass (arrows) in the left hepatic lobe. (b) Coronal T2-weighted single shot fast spin echo image shows a large lobulated heterogeneous hyperintense mass (arrows), surrounding the fissure for ligamentum teres (arrowhead). (c) Axial pre-contrast T1-weighted image shows hypointense mass (arrow) in the left hepatic lobe. (d, e) Axial portal venous (d) and equilibrium (e) phase contrast-enhanced T1-weighted image show poor, heterogeneous enhancement of the mass (arrow). Progressive enhancement is seen in the central portion of the mass. e - 152-
일차성간림프종 f g h j i Fig. 1. (f) Axial 20 minute-delayed hepatobiliary phase contrast-enhanced T1-weighted image clearly shows two different signal intensity of the lesion: lymphoma with very low signal intensity area (arrow) and slightly low signal intensity entrapped by the tumor with necrotic hepatic parenchyma (dotted arrow). (g) Axial diffusion-weighed image (b = 800) shows three different signal intensity of the lesion: a bandlike high signal intensity of the tumor (arrow), thin linear dark signal intensity along the medial margin of the high signal intensity (arrowhead), consistent with necrotic tumor, and intermediate signal intensity area (dotted arrow) entrapped by the tumor consistent with necrotic hepatic parenchyma. (h) F-18 FDG PET-CT shows a band-like hot uptake showing the same configuration with that of diffusion-weighted image, suggestive of a viable tumor. (i) Gross specimen shows three different zones consisting of a bandlike lobulated tumor (arrow), focal tumoral necrosis (arrowhead), and necrotic hepatic parenchyma without tumor involvement (dotted arrow). (j) Photomicrography of specimen (immunohistochemical staining for CD20, 400) shows multiple large atypical lymphoid cells expressing CD20, consistent with diffuse large B-cell lymphoma. - 153-
김한나외 지않았고비정상적인담관확장도없었다. 종괴는지방억제고속스핀에코 T2 강조영상 (TR/TE=2855/80 msec) 에서는불균질한고신호강도로보였고 (Fig. 1a, b) 고속경사에코 T1 강조영상 (TR/TE=240/4.6 msec, Flip angle 80 ) 에서저신호강도로보였다 (Fig. 1c). 지방억제호흡정지 3D 경사에코 (THRIVE, TR/TE = 4.4/2.1 msec, Flip angle 15, echo train 60, Matrix 224 229, NEX 1.0, section thickness/gap 4.0 mm/2.0 mm) 를이용한역동적조영증강검사를시행하였으며신체중량의 kg당 0.025 mmol의 gadoxetic acid (Gd-EOB-DTPA; Primovist, Bayer-Schering pharma, Berlin, Germany) 를주사한후 30 ml의식염수를신속주입하였다. 종괴는동맥기에서는조영증강을거의보이지않았으며문맥기와평형기에는회오리모양으로간실질보다낮게조영증강되었다 (Fig. 1d, e). 조영증강 20분후에얻은간담관기에서종괴의가장자리부분은더낮은저신호강도를보이고중심부는덜낮은신호강도를보였다 (Fig. 1f). 확산강조영상 (b=800) 에서종괴주변부는회오리모양의밴드양상의고신호강도를보였으며그내측에얇은띠모양의매우낮은신호강도를보이는부분이있었고중심부는정상간실질과등신호강도를보였다 (Fig. 1g). 양전자방출단층촬영 (F-18 FDG PET- CT) 에서종괴는주변부에확산강조영상과비슷한밴드양상의강한신호를보이는고대사성병변으로보였고중심부는섭취결손을보였다 (Fig. 1h). 종괴의수술전진단은간내담관암으로생각하였다. 환자는좌간절제술을시행하였으며수술소견은황백색의단단한종괴였고변연은잘국한된분엽상을보였다 (Fig. 1i). 병리소견에서는미만성대세포림프종으로확진되었다 (Fig. 1j). 자기공명영상소견과병리소견을연관하여보면확산강조영상에서주변부에고신호로보였던부분은살아있는림프종세포가있는부위이며그내측으로띠모양의매우낮은신호강도를보이는부분은괴사였고내부에정상간과등신호강도를보인부분은암세포가아닌죽은간세포부위였다. 간담관기영상에서도림프종부위는매우저신호강도를보였으나중심부의죽은간세포부위는약간저신호강도를보였다 (Fig. 1f, g, i). 고찰간은림프종이자주침범하는대표적인림프절외장기로알려져있으나, 간을침범하는림프종은대부분간외림프종으로시작된이차성림프종이다. 간에서기원하는일차성림프종은매우드물어서전세계적으로 100예미만이보고되어있다 (4). 간림프종의영상소견은다양하게보고되었는데크게단일성종괴, 다발성종괴, 침윤성병변의세가지양상으로구분할수있다 (4-6). 이차성간림프종은간외침범이동반되므로영상의학적진단이어렵지않으나, 일차성간림프종중특히단일성종괴로발현하는경우다른간내원발암과의감별이어려워대부분의일차성간림프종의경우수술후확진된다 (7). 하지만림 프종은항암화학요법으로치료하는질환이므로영상의학적으로간림프종을의심하고영상유도하조직검사를하여정확한진단하는것이불필요한수술을피하는데많은도움이된다. 간림프종은초음파검사에서대부분저에코의종괴로보이며, CT에서는거의대부분정상간실질보다낮은음영으로보인다 (6). 조영증강후 CT에서간림프종은대부분간실질보다낮은균일한조영증강을보이며일부에서는반점형조영증강또는고리모양의조영증강양상을보인다 (5, 6). 자기공명영상에서 T1 강조영상에서저신호강도로, T2 강조영상에서는고신호강도로보여, 간림프종의영상소견은특징적인점이없다 (4-6). 또한최근이용이증가하고있는간세포특이조영제를이용한간담관기영상이나확산강조영상소견은보고된바없다. 본증례는좌문맥의배꼽분절을둘러싸는커다란종괴로발견되었고역동적조영증강 CT 및자기공명영상에서시간이지날수록종양중심부의조영증강이강화되는소견과간표면퇴축이동반되어간내담관암을의심하여수술을시행하였으나병리학적으로림프종으로확진되었다. 후향적으로영상소견을분석해보면상당히큰종괴임에도불구하고주변담관확장이동반되지않았고, 종괴의중심부에위치한문맥과간원삭틈새주변의지방층이폐색되지않고잘유지되어있는점등이간내담관암의영상소견과는다른점이라생각된다. 또한간표면퇴축으로판단하였던소견은종괴가중심에위치한문맥및간원삭틈새주변을보존하며자라나서주위간표면을불룩하게만들어생긴이차적인현상으로생각된다. 본증례의흥미로운점은확산강조영상과간담관기조영증강영상소견이육안병리소견과잘일치하는점인데생존종양부위와괴사부위, 또한종양의중심부에위치했던괴사에빠진정상간이서로다른세층의신호강도로구분되어보였다. 림프종은일반적으로주변혈관이나장기의형태를유지하며자라는것이특징인데본증례에서도종괴의중심부에위치한문맥과간원삭틈새주변의지방층이잘유지되었으며이런병리학적소견이확산강조영상과간담관기조영증강영상소견에서잘반영되어보였다. 또한미만성대세포림프종은항암치료를받지않아도림프종자체에괴사부위가생길수있는데이런병리학적소견도영상소견에서잘반영되어보였다 (8). 이런소견들은간내담관암과의감별진단에도움이될것으로생각되며, 간종괴에대한자기공명영상시간세포특이조영제를이용하고확산강조영상을추가하는것이감별진단에도움이될것으로기대된다. 결론적으로본증례는매우드문일차성간림프종으로고식적자기공명영상에서간내담관암과유사하여감별이어려웠으나, 종양의범위와병리학적특징을간세포특이조영제를이용한간담관기영상과확산강조영상이잘반영하므로이들기법의추가가간내종괴평가에도움이되었던증례이다. - 154-
일차성간림프종 참고문헌 1.Peixoto MCG, Filho AAA, Ribeiro ACR, D lppolito G. Non- Hodgkin s lymphoma presenting as a single liver mass. Radiol Bras 2009;42:15-19 2.Miyamoto Y, Izuo M, Ikeya T, et al. Right hepatic lobectomy for primary lymphoma: a case report and literature review. Jpn J Surg 1986;16:292-297 3.Ryan J, Straus DJ, Lange C, et al. Primary lymphoma of the liver. Cancer 1988;61:370-375 4.Noronha V, Shafi NQ, Obando JA, Kummar S. Primary non- Hodgkin s lymphoma of the liver. Crit Rev Oncol hematol 2005;53:199-207 5.Maher MM, McDermott SR, Fenlon HM, et al. Imaging of primary non-hodgkin s lymphoma of the liver. Clin Radiol 2001;56:295-301 6.Gazelle GS, Lee MJ, Hahn PF, Goldberg MA, Rafaat N, Mueller PR. US, CT, and MRI of primary and secondary liver lymphoma. J Comput Assist Tomogr 1994;18:412-415 7.Doi H, Horiike N, Hiraoka A, et al. Primary hepatic marginal zone B cell lymphoma of mucosa-associated lymphoid tissue type: case report and review of the literature. Int J Hematol 2008; 88:418-423 8.Juan Rosai. Rosai and Ackerman s surgical pathology, 9th ed. Mosby edinburg : 1946-1947 J. Korean Soc. Magn. Reson. Med. 14:151-155(2010) Primary Hepatic Lymphoma: MR Imaging and Pathologic Correlation Hanna Kim 1, Yu Ri Shin 1, Sung Eun Rha 1, Eun Sun Jung 2, Soon Nam Oh 1, Joon-Il Choi 1, Seung Eun Jung 1, Young Joon Lee 1 1 Department of Radiology, Seoul St. Mary s Hospital, College of Medicine, The Catholic University of Korea 2 Department of Hospital Pathology, Seoul St. Mary s Hospital, College of Medicine, The Catholic University of Korea Primary hepatic lymphoma is extremely rare, representing less than 1% of all extranodal lymphomas. We report MR imaging features and pathologic correlation of a case of primary hepatic lymphoma. MR images showed a large lobulated mass with gradual contrast enhancement, resembling intrahepatic cholangiocarcinoma. However, both hepatobiliary phase image obtained 20 minutes after injection of hepatocyte specific contrast agent and diffusion-weighted image demonstrated characteristic three layered pattern representing viable lymphoma in the outer layer, tumor necrosis in the middle layer and necrotic hepatic parenchyma in the center. Index words : Lymphoma Liver Magnetic resonance imaging (MRI) Address reprint requests to : Yu Ri Shin, M.D., Department of Radiology, Seoul St. Mary s Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul 137-701, Korea. Tel. 82-2-2258-1455 Fax. 82-2-599-6771 E-mail: crystal57@catholic.ac.kr - 155-