대한내분비외과학회지 : 제8권제1호 Vol. 8, No. 1, March 2008 증례 갑상샘의미만성경화아형유두상암의 1 예보고 : 초음파와컴퓨터단층촬영영상 춘천성심병원영상의학과, 1 외과, 2 병리과 김흥철ㆍ남궁숙ㆍ홍명선ㆍ황임경ㆍ김한준 1 ㆍ최영희 2 A Case Report on Diffuse Sclerosing Papillary Carcinoma of the Thyroid: The Ultrasound and CT Images Heung Cheol Kim, M.D., Sook Namkung, M.D., Myong Son Hong, M.D., Im Kyung Hwang, M.D., Han Joon Kim, M.D. 1 and Young Hee Choi, M.D. 2 We report here on a case of diffuse sclerosing papillary carcinoma (DSPC), which is a subtype of papillary carcinoma of thyroid, in a 27-year-old female. The ultrasound images showed diffuse enlargement of the thyroid lobes and this was associated with underlying diffuse scattered microcalcifications and a heterogeneous hypoechoic background parenchyma that was without any masses. The CT image showeddiffuse scattered dot-like hyperdensities with bilateral multiple metastastic lymph nodes. Because making the cytological diagnosis of DSPC is still challenging, the radiological findings that show this disease s characteristic features may be important clues for making the correct diagnosis. (Korean J Endocrine Surg 2008;8:43-47) Key Words: Thyroid, Papillary carcinoma, Diffuses sclerosing variant, Ultrasonography, CT 중심단어 : 갑상샘, 유두상암, 미만성경화아형, 초음파, 컴퓨터단층촬영 Departments of Radiology, 1 Surgery, 2 Pathology, Chunchon Sacred Heart Hospital, Chuncheon, Korea 서 갑상샘의유두상암 (papillary carcinoma) 은전체일차성갑상샘암의 70 80% 를차지하며,(1,2) 이중대부분은고전형 론 책임저자 : 김흥철, 강원도춘천시교동 153 200-060, 춘천성심병원영상의학과 Tel: 033-240-5158, Fax: 033-242-7085 E-mail: khc@hallym.or.kr 게재승인일 :2008 년 2 월 27 일 43 (classic type), 소포형 (follicular type), 피막형 (encapsulated type) 등이차지하지만, 이외에다른여러아형들이존재하며최근보고들에의하면이들은예후에영향을주는고전형유두상암과는다른생물학적성질들을갖는다. 그중미만성경화유두상암 (diffuse sclerosing papillary cancer, DSPC) 은매우드문아형이며임상적으로매우공격적인특성을갖는다. 그러므로이질환의조기진단은갑상샘암환자들의치료방법을선택하고예후를결정짓는데매우중요하다. 그러나이질환은진단이어렵고임상적으로갑상샘염과혼동하기쉬우므로진단이지연될수있다.(3) 저자들은일반적인유두상암과는다른특징적인방사선학적소견을보였던 DSPC 1예를임상소견및수술, 조직소견과함께보고한다. 증례 27세여자환자가내원약 6개월전에우연히발견되어서서히크기가증가하는양측갑상샘의종괴를주소로내원하였다. 환자는과거력과가족력에서특이소견없었다. 이학적검사에서갑상샘양엽에경계가그려지지않는연한무통성종괴가관찰되었고압통은없었으며, 인접한우측흉쇄유돌근의내연을따라커진림프절들이여러개촉지되었다. 갑상샘기능에대한검사결과는 TSH 1.70 uiu/ml ( 정상 : 0.35 4.94), T4 8.1ug/dl ( 정상 : 4.87 11.73) free T4 1.14 ng/dl ( 정상 : 0.89 1.76), T3 107.2 ng/dl ( 정상 : 58 159) 으로정상범위에속했다. 초음파는 HDI5000 (Philips-ATL, Bothell, WA, USA) 의선형탐촉자 (5 12 MHz) 를사용하였다. 초음파검사에서갑상샘양엽에미만성종대를보였고전반적으로불균질한저음영에코가보였으며, 우엽에는약 0.5 cm 크기를보이는저에코음영의고립성소결절이관찰되었다. 갑상샘우엽의대부분에미세석회화를시사하는점상고에코음영 (punctate hyperechogenicity) 들이미만성으로분포하였고, 고립성소결절이외에다른경계가그려지는종괴는관찰되지않았다 (Fig. 1A, B). 갑상샘우엽과인접한부위에분엽성외연을보이는최대직경이 1 cm 이상으로커진림프절들이다발성으로관찰되었고각각은편심성피질두께증가 (eccentric cortical thickening), 증
44 대한내분비외과학회지 : 제 8 권제 1 호 2008 Fig. 1. Sonographic findings of thyroid DSPC. (A, B) Axial (A) and longitudinal (B) scans show heterogeneous hypoechoic parenchymas and abundant diffuse scattered psammoma bodies as punctate strong echos in thyroid parenchymas. A ill defined small hypoechoic and solid nodule is noted (white arrow). (C) Longitudinal sonogram show multiple nodal metastases with eccentric cortical thickenings, loss of central hyperechogencity and foci of calcification (white arrow). 가된주변부의혈관분포 (increased peripheral vascular distribution) 및림프절문부의정상고에코음영소실등의악성림프절을시사하는소견들이보였고, 갑상샘우엽과마찬가지로내부에미세석회화과관찰되었다 (Fig. 1C). CT 검사에서는미세석회화가갑상샘우엽에전반적으로, 갑상샘좌엽에는일부에서흩어져관찰되었고, 갑상샘우엽에조영증강이덜되는고립성소결절이보였다 (Fig. 2). 동반되어비균질한조영증강을보이는림프절들이우측 level 3, 4에서다발성으로관찰되었다 (Fig. 2B). 초음파유도하에갑상샘우엽에있는저에코음영의소결절과다발성점상고에코음영부위, 커진우측 level 3 경부림프절에서각각미세바늘흡인세포검사를시행하였다. 갑상샘우엽의고립성저에코음영결절에서시행한미세바늘흡인세포검사결과에서유두상암으로진단되었고점상고에코음영부위에서는림프구들이흩어져있는소견을보여갑상샘염으로진단하였다. 우측경부림프절은갑상샘유두상암의전이성림프절로진단되었다. 환자는전신마취하에양측갑상샘전절제술과우측변형근치경부절제술을시행하였고, 동결절편에서종양의침윤을보였던좌측부갑상샘및인접한림프절 을포함한갑상샘좌엽의주변조직을같이제거하였다. 제거된갑상샘우엽은 5 3 2 cm 크기를보였고갑상샘좌엽은 3 3.5 2.5 cm 크기였다 (Fig. 3A). 수술중동결절편을위해보내온갑상샘우엽에서는불명확한경계를보이는 0.5 cm 크기의결절이관찰되었고, 단면은하시모토갑상샘염을연상케하는약간단단한구조물이었다 (Fig. 3B). 조직검사에서갑상샘우엽의전반에걸쳐유두상암이관찰되었고다수의모레종체 (psammoma body) 가보였으며그사이로섬유화, 소량의편평상피세포화, 림프관내에작은암종등이관찰되었다 (Fig. 4). 갑상샘좌엽은일부에흩어져있는작은유두암종들이관찰되었고, 갑상샘양엽에서림프여포 (lymphoid follicle) 들과림프구들이미만성으로분포하였다 (Fig. 4). 조직검사에서갑상샘우엽에미만성, 좌엽은국소성침범을보이는유두상암의미만성경화아형 (diffuse sclerosing subtype) 으로진단되었고, 좌측부갑상샘을포함한양측갑상샘의주변조직으로의종양의침범이있었다. 우측경부림프절 (lateral group) 은제거된 33개의림프절중 8개에서전이의소견을보였고, 중심림프절 (central group) 은제거된 7개의림프절중 4개의림프절에서암전이의소견을
김흥철외 : 갑상샘의미만성경화아형유두상암의 1 예보고 : 초음파와컴퓨터단층촬영영상 45 Fig. 2. Axial CT images of thyroid DSPC. (A) Pre-contrast CT image shows diffuse punctate calcific densities in both thyroid lobes, findings indicative of microcalcifications (white arrow). (B) Axial contrast-enhanced CT image shows heterogeneous enhanced both thyroid parenchymas and multiple enhanced metastatic lymph nodes with ill defined margins in right neck (white arrow). A poorly enhanced small nodule is noted in right thyroid lobe (arrowhead). Fig. 3. Gross specimen of both thyroid DSPC. (A) This thyroid shows firm parenchyma. But no obvious mass is found. (B) The cut surface shows ill defined gray and white areas without formation of any masses. The background parenchyma is firm and somewhat white appearance. 보였다. 환자는수술후고용량방사성요오드요법치료를받았고, 좌측경부림프절에대해서는초음파검사및미세바늘흡인세포검사를통한주의깊은추적검사를통해전이가발견되면변형근치경부절제술도시행할예정이다. 고찰갑상샘유두상암은여러아형들로분류되며일부아형들은갑상샘조직이외로전이를하며수술시불완전절제의가능성이높은매우공격적인생물학적양상을보인다.(2,4,5) 갑상샘유두상암의아형중 DSPC 아형은매우드문갑상샘
46 대한내분비외과학회지 : 제 8 권제 1 호 2008 Fig. 4. Histopathologic appearance of the DSPC (H&E stain, 200). Numerous psammoma bodies (white arrow) with neoplastic cells are noted (black arrow). Fibrous stroma with heavy lymphocytic infiltration is noted (arrowhead). 의악성종양으로전체유두상암의 0.75 5.3% 를차지하며,(4,5) 일부에서는 0.02 0.03% 등의매우낮은빈도로보고되고있다.(3,6) 이아형은여자에게호발하지만고전형유두상암과비교하여좀더젊은연령에나타나며,(3,5-7) 종괴가더크고, 림프절전이를포함하여갑상샘이외의조직으로전이를더잘한다.(5,6) 일부보고에서는폐와뇌에도전이가보고되는등더욱공격적인양상을보이며, 치료후재발이흔한것으로알려져있다.(5,8,9) 또한 anti-thyroglobulin autoantibody가양성인경우가흔하며갑상샘의양측혹은편측성미만성종대를보이기때문에하시모토갑상샘염과구별이어렵고, 조기발견및수술전진단이지연될수있다.(4,7,10,11) DSPC 아형은고전형유두상암과비교하여예후가더나쁜것으로알려져있지만,(6) 일부에서는비슷한결과를보였던경우등이있는데,(3,4) 이는고전형유두상암보다더욱공격적인치료의결과로생각되며, 대부분은양측갑상샘전절제술, 변형근치경부절제술, 수술후 131 I 방사선요법등을시행한다.(3,5) 유두상암의아형들중 tall cell, columnar cell, DSPC 아형들은좀더공격적성향을가지며, 고전형유두상암과는다른임상적양상과예후를보이므로, 수술전진단은환자의치료방법결정및예후에매우중요하다.(8,12) 갑상샘종양의진단에있어서초음파유도하의수술전미세바늘흡인세포검사는경제적인면과접근의용이성, 높은정확도등으로현재유두상암을진단하는데매우유용한방법으로사용되고있다.(13,14) 일반적으로고전형유두상암은세포학적형태와조직학적소견간에높은연관관계를보이므로미세바늘흡인세포검사가수술전진단방법으로보편화되어있다.(2,13) 그러나세포학적검사를통해유두상암을다양한아형으로분류할수있는능력에대해서는저자들 마다이견이있으며, 검체습득방법이나검사자요인, 유두상암의아형에따라다양한결과들을보일수있다.(1,8,15) DSPC 아형의세포와조직소견간의연관관계에대한연구에서특정아형으로분류자체가불가능했던경우와, DSPC 아형의조직학적특징인섬유화소견은미세바늘흡인세포검사의펴바른표본에서는발견할수없기때문에 DSPC 아형을세포학적으로진단하기에어려웠던경험들이보고되어있다.(2,15,16) DSPC 아형의조직병리소견은미만성침범, 경화, 풍부한모레종체, 편평상피화생, 광범위한림프관침투등이며, 특징적소견인갑상샘내에넓게분포하는모레종체는방사선학적으로도중요한진단적요소이다. (10,11,17) 과거에는모레종체에의한미세석회화는연조직일반방사선촬영을이용하여관찰하였지만,(3) 현재는보편화된고해상초음파를통해방사선피폭없이쉽게진단할수있다. 고전형유두상암에대한초음파소견은많이알려져있지만,(18,19) DSPC 아형의초음파소견은문헌으로는드물게보고되고있다. DSPC의초음파소견으로편측혹은양측갑상샘에모레종체를시사하는미세석회화들이미만성으로산재하며, 내부에저에코음영결절들이동반될수있다. 광범위한섬유화와림프구의침윤으로미만성갑상샘종대와갑상샘실질에비균질적저에코음영등이관찰되며이러한초음파소견때문에만성갑상샘염과혼동하기쉽다.(9-11,16) 유두상암의수술전진단에있어서일반적인형태의고전형유두상암을공격적임상양상을보이는다른아형들과구별하는것은수술방법및향후치료계획을세우는데있어서매우중요하다.(1) 저자들의경우에서와마찬가지로세포학적분석을통한유두상암의진단은가능하나이를다양한아형들로분류하는것은어려운점이있다. DSPC 아형은초음파나 CT 검사에서종괴의형태가잘그려지지않는미만성미세석회화를보이며주변에전이성림프절을보이는등비교적특징적인방사선학적소견을보이므로, 미세바늘흡인세포검사를통한세포학적분석과영상소견을함께고려하면수술전진단이용이할수있다. 만약 DSPC 아형이의심될경우다른장기로의전이여부등좀더적극적이고정확한수술전검사가필요하며, 이를통해적절한치료계획을수립하는것이매우중요할것으로생각된다. REFERENCES 1) Furlan JC, Bedard YC, Rosen IB. Role of fine-needle aspiration biopsy and frozen section in the management of papillary thyroid carcinoma subtypes. World J Surg 2004;28: 880-5. 2) Gupta S, Sodhani P, Jain S, Kumar N. Morphologic spectrum of papillary carcinoma of the thyroid; role of the cytology in
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