Pictorial Essay pissn 1738-2637 / eissn 2288-2928 J Korean Soc Radiol 2013;69(5):365-371 http://dx.doi.org/10.3348/jksr.2013.69.5.365 Paragonimiasis: Pictorial Essay 1 폐흡충증의영상소견 : 임상화보 1 Kyung Nyeo Jeon, MD 1, Mi Jung Park, MD 1, Kyungsoo ae, MD 1, Hae Young hoi, MD 1, Ho heol hoi, MD 1, Jae oem Na, MD 1, Dae Seob hoi, MD 1, Ho heol Kim, MD 2, In Seok Jang, MD 3, Dong hul Kim, MD 4 Departments of 1 Radiology, 2 Internal Medicine, 3 Thoracic Surgery, 4 Pathology, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea Pleuropulmonary paragonimiasis is a parasitic infection caused by lung flukes including Paragonimus westermani. Paragonimiasis usually occurs from ingestion of raw or improperly cooked freshwater crabs or crayfish. Pleural or lung parenchymal lesions are commonly found on T or chest radiographs, and radiologic manifestations of pleuropulmonary paragonimiasis vary with the stage of the disease. Early findings include pneumothorax or hydrothorax, focal air-space consolidation, and linear opacities. Later findings include thin-walled cysts, mass-like consolidation, nodules, or bronchiectasis. Pulmonary paragonimiasis often can be mistaken for pulmonary tuberculosis in tuberculosis-endemic areas or lung cancer when it presents as a solitary pulmonary nodule. Intraperitoneal or ectopic lesions such as those in the retroperitoneum can form during migration of a juvenile worm from the small intestine to the lungs. lthough the symptoms and signs of pulmonary paragonimiasis are nonspecific, an early diagnosis can be made if radiologists understand the pathogenesis and typical imaging findings of the disease. The purpose of this report was to demonstrate the various imaging findings of pleuropulmonary paragonimiasis and to review articles to help radiologists make a proper diagnosis. Index terms Paragonimiasis Lung Infection omputed Tomography Received July 25, 2013; ccepted September 17, 2013 orresponding author: Kyungsoo ae, MD Department of Radiology, Gyeongsang National University Hospital, 79 Gangnam-ro, Jinju 660-702, Korea. Tel. 82-55-750-8211 Fax. 82-55-758-1568 E-mail: ksbae@gnu.ac.kr This is an Open ccess article distributed under the terms of the reative ommons ttribution Non-ommercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 서론 폐흡충증의원인으로아시아지역에서는 Paragonimus Westermani 가가장흔하며민물에사는다슬기, 가재나게를중간숙주로한다. 사람은민물가재나게등을날것으로, 또는적절히조리하지않고섭취함으로써감염된다. 한국, 일본, 태국, 인도, 라오스, 필리핀등의동아시아나동남아시아지역과남미, 아프리카등에서흔한데, 특히한국에서는민물가재즙을마시거나민물게장을즐겨먹는지역에서많이발생한다 (1). 음식과함께섭취된피낭유충이사람의소장에서탈낭 (excyst) 하여장관벽을뚫고복강으로나와횡격막을통과하여흉막을통해폐실질에침범하여성충으로자라고알을낳는병태생리가잘알려져있다 (Fig. 1)(2, 3). 그러므로복강에서폐실질로이동하는경로중병변이발견되는시기에따라다양한영상소견을볼수있다. 증상이비특이적인경우가많아영상소견에서폐 흡충증을의심하지못하는경우진단이지연될수있다. 영상소견과더불어말초혈액호산구증가가있고, 민물게나가재를생식한병력이있는경우의심할수있으며, 확진은객담이나기관지흡인물, 흉수, 조직, 대변등에서기생충의알을발견하거나혈청면역검사에서폐흡충의특이적항체를측정함으로써가능하다. 폐흡충증의영상소견을폐, 흉막, 그리고흉곽외병변으로나누어살펴보도록하자. 폐병변 폐흡충증의폐실질병변은병의진행단계와주위조직반응에따라다양한소견을보인다. 초기에는유충이흉막에서폐로이동하는과정에서출혈성폐렴이발생하고이는영상검사에서폐경화와주위간유리음영의형태로보인다 (Fig. 2). 추적영상검사에서종종폐경화와간유리음영의위치와모양이변 opyrights 2013 The Korean Society of Radiology 365
폐흡충증의영상소견 하는것을볼수있다. 이후에기생충은성장하면서폐실질에 정착하여기생충낭을형성하는데, 기생충낭이기관지와교통하 게되면영상소견에서주위에폐경결이나간유리음영을동반 Small intestine Larvae experience excystation Small intestine wall Peritoneal cavity Diaphragm pleura Fig. 1. Pathogenesis of pleuropulmonary paragonimiasis. Lung Mature to adult flukes 한공동성병변으로보이게된다 (Fig. 3). 반면, 기생충낭이기관지와교통하지않으면내부저음영부분을가진폐경화나주변부폐결절또는종괴의형태로보이게된다 (Fig. 4). 이것은병리적으로기생충이나성충이낳은알에의해소혈관이폐쇄되어실질에허혈성괴사가일어나고기관지가확장된것으로, 내부에암갈색의괴사성혹은출혈성액체가찬것이다 (3). 이처럼폐의주변부에결절이나종괴의형태로보이는경우내부저음영이부위를발견하는것이진단에도움이될수있다. 병변이폐실질에위치한경우다른질환과감별에있어흉막으로부터이어지는선상음영을발견하는것이진단에중요한단서가될수있는데, 이것은유충이이동한경로또는충란에의해소기도가폐쇄되어생기는국소무기폐의소견이다 (Fig. 3, 4). 최근우리나라 3차병원의보고에의하면, 폐흡충증이중 Fig. 2. Pleuropulmonary paragonimiasis in a 71-year-old man presented with fever for 1 month.. xial thin-section chest T at lung window setting shows a focal consolidation in right upper lobe abutting to the minor fissure (arrow) and multiple small subpleural and fissural nodules. Hydropneumothorax is also noted on the left.. serpentine tubular structure (arrowheads) is seen in right middle lobe, which suggests worm migration track. Paragonimus westermani antibody titer was increased, and the lesions were resolved after chemotherapy with praziquantel. Fig. 3. Pleuropulmonary paragonimiasis in a 43-year-old man.. xial thin-section chest T at lung window setting shows subpleural consolidation and an irregular cavity in left upper lobe. Note linear opacities connecting the pleura and the lesions (arrows).. nother consolidation with cavity and ground-glass opacity is seen in right lower lobe. 366 대한영상의학회지 2013;69(5):365-371 jksronline.org
전경녀외 년의환자에서특별한증상없이단일폐결절로보여폐암과의감별을요하는경우가많았다고하며, 이런경우조직검사나불필요한수술을하게되는경우도종종있다 (Fig. 5)(4, 5). 기관지주위에형성된기생충낭이기관지와교통하게되고, 기생충또는알에의해형성된육아종이기관지를막게되면폐엽또는폐구역허탈의소견을보일수있다 (Fig. 6). 병의후반기나치유기에는얇은낭성병변이나기관지확장의형태로보인다 (Fig. 7F). Fig. 4. Pleuropulmonary paragonimiasis in a 62-year-old man.. xial chest T scan shows multiple low attenuation cysts within peripheral consolidation in left upper lobe.. There is another small nodule in superior aspect. Note a linear opacity abutting the pleura (arrow). There was eosinophilia (19.5%) in the peripheral blood.. Microscopic examination reveals multiple granulomas (stars) containing eggs of Paragonimus westermani (arrows). Fig. 5. Pleuropulmonary paragonimiasis presenting as a solitary pulmonary nodule in a 52-year-old man.,. The nodule seems to be located centrally, but shows subpleural location with focal thickening of the mediastinal pleura (arrow in ).. Percutaneous transthoracic biopsy was done under T-guidance. High-power photomicrograph ( 400 μm) shows an egg of Paragonimus westermani (arrow). Fig. 6. Pleuropulmonary paragonimiasis presenting as lobar atelectasis in a 60-year-old woman.. Initial chest P shows left lower lobe atelectasis (arrows).. xial chest T scan at mediastinal window setting shows left lower lobe atelectasis with mucoid impaction in the bronchi. Ova morphologically resembling Paragonimus westermani were detected in sputum.. Follow-up chest P in 2 weeks after praziquantel treatment shows resolution of left lower lobe atelectasis. jksronline.org 대한영상의학회지 2013;69(5):365-371 367
폐흡충증의영상소견 폐흡충증의임상증상이기침, 발열, 객담, 혈담과같이폐결핵과유사하여폐결핵유병률이높은지역에서폐결핵으로오인되어진단이지연되고불필요한항결핵화학요법을받게되는경우가드물지않다 (5, 6). 폐결핵과의감별점은폐흡충증의경우첫째, 영상검사에서병변의모양과위치가빠르게변화하고둘째, 결절보다는경계가불분명한폐경화로나타나는경우가 더흔하며, 셋째로폐결핵과달리치료후에섬유화나폐실질파괴의후유증을남기는경우가드물다는것이다 (Fig. 7)(3, 6). 흉막병변 소장에서복강으로나온유충은감염후 3~8 주에횡격막을 D E F Fig. 7. Pleuropulmonary paragonimiasis in a 44-year-old woman working in a restaurant serving soybean sauced freshwater crabs (Kejang). -. hest T scans obtained at an outside clinic show focal consolidation with ground-glass opacity in right upper lobe, a peripheral nodule in right lower lobe, and a cavity with ground-glass opacity in left lower lobe. Right pleural effusion is also seen. nti-tuberculous medication was started without any bacteriologic evidence. D-F. hest T scans obtained after 2 months of anti-tuberculous medication show new lesions in left upper lobe and right middle lobe. avity in left lower lobe was changed to thin-walled cysts (arrow in F). Fig. 8. Pleuropulmonary paragonimiasis with pneumothorax in a 59-year-old woman.. xial chest T scan at lung window setting shows right side pneumothorax. Note a subpleural parenchymal lesion in right upper lobe (arrow).. t the lower level, bilateral pleural effusion is seen. 368 대한영상의학회지 2013;69(5):365-371 jksronline.org
전경녀외 Fig. 9. Pleuropulmonary paragonimiasis with focal pleural hemorrhage in a 59-year-old woman.. xial chest T scan at mediastinal window setting shows pleural effusion with focal hemorrhage (arrows) on the left.. small subpleural nodule with central low attenuation is seen in lingular segment. Fig. 10. Pleuropulmonary paragonimiasis in a 29-year-old woman.. xial chest T scan at mediastinal window setting shows pleural effusion with abscess (arrow) on the left.. cavitary lesion with subpleural linear opacity is noted in right upper lobe. Fig. 11. bdominal paragonimiasis in a 45-year-old man.. ontrast enhanced T scan shows a mass with central low density in the lesser omentum (arrow).. Multiple small cavities and a subpleural line are noted in left upper lobe. jksronline.org 대한영상의학회지 2013;69(5):365-371 369
폐흡충증의영상소견 Fig. 12. Retroperitoneal paragonimiasis in a 58-year-old man. ontrast enhanced T scans with axial () and coronal reformation () show an abscess in the left posterior pararenal space (black arrows). small nodule with central low attenuation is seen in left lower lobe (white arrow in ). 뚫고흉막을침범한다. 폐흡충증에의한흉막병변으로는국소흉막비후, 기흉, 흉수, 혈흉, 흉막농양등이생길수있다 (3, 7). 유충이폐실질로이동하기위해흉막을침범하는과정에서흉막결손이생겨서기흉이발생할수있고염증반응에의해흉수가흔히동반된다 (Fig. 8). 특별한원인없이양측성으로발생한기흉이나흉수가있는경우, 유병률이높은지역에서는반드시폐흡충증가능성을의심해야한다 (6). 후향적으로보면많은경우에서국소흉막비후가폐실질병변주위에서보이는데이것은병변이흉막으로부터기시하였음을시사하는것으로폐흡충증의진단에유용한단서가될수있다 (7). 유충의이동과정에혈관손상이생겨서국소혈흉이동반되기도하고 (Fig. 9), 드물게유충이나알에의한염증반응으로흉막표면에농양을형성하기도한다 (Fig. 10). 폐, 흉막외의병변 드물지만폐흡충에의해폐와흉막외의전신장기에이소성병변이생길수있다. 복부는폐흡충이이동하는경로에속하므로폐와함께흔히침범되는곳이다. 소장에서탈낭하여복강으로나온유충이폐로이동하는과정에서염증에의해복수가생기고복막이나대망에침윤과결절을형성하여결핵성또는악성복막염과유사한소견을보이거나, 큰종괴를형성하여악성종양과혼돈을일으킬수있다 (Fig. 11)(8-10). 결절이나종괴는기생충감염에의한육아종으로병의진행단계에따라고형또는낭성이거나석회화된소견으로보일수있다. 그외에도폐외의다양한경로로이동하여심낭등의종격동이나, 신장이나요관주위후복막강, 복벽, 피하, 간, 비장, 뇌나척수, 안구등의여 러장기에이소성병변을만들기도한다 (Fig. 12)(11, 12). 폐흡충증은대개 3일동안의일회성화학요법 (praziquantel) 으로치료가가능하다고알려져있지만, 증상이나타난기간이길고, 폐흡충에대한혈청면역검사에서항체의단위가높거나, 폐병변의수가많은환자의경우재발할수있으므로치료후추적검사가필요하다 (13). 이상의폐흡충증의병리기전을이해하고폐와흉막등에서보이는특징적인영상소견을인지하고있으면, 조기에진단을할수있고유사한영상소견을보이는병변과의감별에유용할것이다. 참고문헌 1. hoi DW. Paragonimus and paragonimiasis in Korea. Kisaengchunghak hapchi 1990;28 Suppl:79-102 2. hoi WY, Lee OR, Jin YK, hi JG. [Lung findings in experimental Paragonimiasis]. Kisaengchunghak hapchi 1979; 17:132-146 3. Im JG, Kong Y, Shin YM, Yang SO, Song JG, Han M, et al. Pulmonary paragonimiasis: clinical and experimental studies. Radiographics 1993;13:575-586 4. Song JU, Um SW, Koh WJ, Suh GY, hung MP, Kim H, et al. Pulmonary paragonimiasis mimicking lung cancer in a tertiary referral centre in Korea. Int J Tuberc Lung Dis 2011; 15:674-679 5. Jeon K, Koh WJ, Kim H, Kwon OJ, Kim TS, Lee KS, et al. linical features of recently diagnosed pulmonary para- 370 대한영상의학회지 2013;69(5):365-371 jksronline.org
전경녀외 gonimiasis in Korea. hest 2005;128:1423-1430 6. Im JG, Whang HY, Kim WS, Han M, Shim YS, ho SY. Pleuropulmonary paragonimiasis: radiologic findings in 71 patients. JR m J Roentgenol 1992;159:39-43 7. Kim TS, Han J, Shim SS, Jeon K, Koh WJ, Lee I, et al. Pleuropulmonary paragonimiasis: T findings in 31 patients. JR m J Roentgenol 2005;185:616-621 8. Kim SY, Ha HK. Peritoneal manifestations of parasitic infection. bdom Imaging 2008;33:172-176 9. Shim SS, Kim Y, Lee JK, Lee JH, Song DE. Pleuropulmonary and abdominal paragonimiasis: T and ultrasound findings. r J Radiol 2012;85:403-410 10. Lee H, Kim JH, Moon WS, Lee MR. Paragonimiasis in the abdominal cavity and subcutaneous tissue: report of 3 cases. Korean J Parasitol 2012;50:345-347 11. Jeong MG, Yu JS, Kim KW, Kim JK, Kim SJ, Kim HJ, et al. Retroperitoneal paragonimiasis: a case of ectopic paragonimiasis presenting as periureteral masses. J omput ssist Tomogr 1999;23:696-698 12. Kong Y, ho SY, Han MH, Goo JM, Yu IK, Shin YM, et al. n experimental study on cerebral paragonimiasis using cats. J Korean Radiol Soc 1994;30:1003-1012 13. Oh IJ, Kim YI, hi SY, an HJ, Kwon YS, Kim KS, et al. an pleuropulmonary paragonimiasis be cured by only the 1st set of chemotherapy? Treatment outcome and clinical features of recently developed pleuropulmonary paragonimiasis. Intern Med 2011;50:1365-1370 폐흡충증의영상소견 : 임상화보 1 전경녀 1 박미정 1 배경수 1 최혜영 1 최호철 1 나재범 1 최대섭 1 김호철 2 장인석 3 김동출 4 폐흡충증은 Paragonimus westermani 등의폐흡충에의한기생충감염질환으로, 주로날것이나적절히조리되지않은민물가재나게를섭취함으로써생긴다. 영상검사에서흉막과폐실질의병변을주로볼수있으며진단당시질병의단계에따라다양한영상소견을보인다. 초기에는기생충이이동하면서기흉, 흉수, 국소폐경결, 선상음영을보이고후기에는기생충낭에의한낭종이나폐결절, 기관지확장증의형태로보이게된다. 종종폐결핵과오인되기도하고단일폐결절의형태로보이는경우는폐암과혼동이되기도한다. 또한기생충이복강에서폐로이동하는과정에서복강에종괴를형성하거나후복막강등에이소성병변이생길수있다. 증상이비특이적이지만, 이러한병태생리를이해하고특징적인영상소견을숙지한다면조기진단할수있다. 이논문은폐, 흉막, 흉곽외부에나타난폐흡충증의다양한영상소견을제시하고문헌을제고하여폐흡충증의진단에도움을주고자한다. 경상대학교의학전문대학원경상대학교병원 1 영상의학과, 2 내과, 3 흉부외과, 4 병리과 jksronline.org 대한영상의학회지 2013;69(5):365-371 371