449Copyrights © 2013 The Korean Society of Radiology

INTRODUCTION

Pulmonary hamartomas are benign lesions composed of an abnormal mixture of epithelial and mesenchymal elements, such as cartilage, fat, fibromyxoid tissue, smooth muscle and bone (1, 2). These benign lesions used to be considered develop-mental abnormalities, but now they are considered benign mes-enchymal neoplasms. Pulmonary hamartomas are the third

most common type of pulmonary nodule, and they account for approximately 5% of solitary pulmonary tumors and 75% of be-nign lung tumors (3-5).

On CT, pulmonary hamartoma usually appears as a smooth or slightly lobulated, peripheral solitary pulmonary nodule (SPN) (5). The presence of fat or popcorn-like calcifications may enable a confident diagnosis; yet, these findings are only visual-ized by CT in approximately 30% of cases (5, 6). In many cases,

Original ArticlepISSN 1738-2637 / eISSN 2288-2928J Korean Soc Radiol 2013;69(6):449-455http://dx.doi.org/10.3348/jksr.2013.69.6.449

Received July 17, 2013; Accepted September 13, 2013Corresponding author: Yeon Joo Jeong, MDDepartment of Radiology, Pusan National University Hospital, Pusan National University School of Medicine, 179 Gudeok-ro, Seo-gu, Busan 602-739, Korea.Tel. 82-51-240-7354 Fax. 82-51-244-7534E-mail: jeongyj@pusan.ac.kr

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distri-bution, and reproduction in any medium, provided the original work is properly cited.

Purpose: To describe the dynamic CT findings of pulmonary hamartoma and to compare these findings with histopathologic findings.Materials and Methods: The Institutional Review Board approved this retrospec-tive study and the requirement for patient informed consent was waived. The he-modynamic CT features of 11 patients (M : F = 6 : 5; mean age, 53.6 years) with pathologically proven pulmonary hamartoma were evaluated. All 11 patients under-went enhanced dynamic CT using a helical technique. A series of images were ob-tained throughout each nodule with 2.5-mm collimation at 0, 30, 60, 90 and 120 seconds and at 4, 5 and 15 minutes after an intravenous injection of contrast medi-um. Extents and patterns of enhancement were correlated with histologic tumor components.Results: All 11 tumors showed persistent enhancement with variable degrees of net enhancement [mean tumor peak enhancement, 48.6 ± 19.0 Hounsfield unit (HU); mean tumor net enhancement, 31.9 ± 11.8 HU] and thick capsular and septal en-hancement. Histologically, all 11 tumors were composed of mature cartilage and loose mesenchymal tissue. A significant positive correlation was found between the net enhancement values and loose connective tissue component percentages (r = 0.749, p = 0.008); further, a negative correlation was found between the net en-hancement values and cartilaginous component percentages (r = -0.813, p = 0.002). Conclusion: On dynamic CT, hamartoma exhibited persistent enhancement without washout as well as thick capsular and septal enhancements. Net enhancement values were found to be positively correlated with the proportion of the loose connective tis-sue component. Thick capsular and septal enhancements were attributed histopatho-logically to loose connective tissue, separating tumors into cartilaginous lobules.

Index termsLung Neoplasm HamartomaMultidetector Computed TomographyPathology

Dynamic CT Findings of Pulmonary Hamartoma: A Comparison with Histopathologic Findings1

폐과오종의 역동적 전산화단층촬영 소견: 조직병리학적 소견과의 비교1

Wanglae Cho, MD1, Yeon Joo Jeong, MD1, Chang Hun Lee, MD2, Ji Won Lee, MD1, Kun-Il Kim, MD3, Jeong A Yeom, MD3, Yeong Dae Kim, MD4

Departments of 1Radiology, 2Pathology, 4Thoracic and Cardiovascular Surgery, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Busan, Korea3Department of Radiology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine and Medical Research Institute, Yangsan, Korea

Dynamic CT Findings of Pulmonary Hamartoma

450 jksronline.orgJ Korean Soc Radiol 2013;69(6):449-455

calcified SPN, ranging from 7 mm to 30 mm detected on the chest radiograph or non-enhanced chest CT scans. Written in-formed consent regarding the dynamic CT protocol was ob-tained from all patients. Before the IV injection of contrast mate-rial, an unenhanced series of images were obtained throughout each nodule, over 30 mm of the z-axis with 2.5-mm collimation at 120 kVp and 90 mA. Thereafter, an additional series of images were obtained at 30, 60, 90 and 120 seconds and at 4, 5 and 15 minutes intervals after commencing the contrast injection using the same imaging parameters used for the initial pre-enhance-ment series. An amount of 1.5 mL/kg (body weight) of Iomeron 300 (Iomeprol, 300 mg iodine/mL; Bracco; Milan, Italy) was in-jected at an infusion rate of 3 mL/s using a power injector (MCT Plus; Medrad; Pittsburgh, PA, USA). Immediately after dynamic imaging at 120 seconds, helical CT scans (125 mA, 120 kVp, 5-mm collimation) were obtained from the lower neck to the level of the middle portion of both kidneys. The estimated total lung radiation dose ranged from 4.1 to 6.8 mSv [mean ± stan-dard deviation (SD), 4.4 ± 1.7 mSv]. The image data were refor-matted with a section thickness of 2.5 mm for transaxial images, and the reconstructed images obtained were interfaced directly with picture archiving and a communication system (M-view; INFINITT Healthcare, Seoul, Korea), which displayed the im-ages on two monitors (2048 × 2560 image matrices, 10-bit view-able gray scale, and 145.9-ft-Lambert luminescence). Both me-diastinal [width, 400 Hounsfield unit (HU); level, 25 HU] and lung (width, 1500 HU; level, -700 HU) window images were viewed on these monitors.

Image Interpretation

Two chest radiologists, one with 10 and the other with 2 years of chest CT experience, independently evaluated the images.

The morphologic features of nodules determined by analyz-ing the unenhanced thin-section CT scans included size, shape, margin characteristics and the presence of calcification and fat. Nodule size was defined as the long-axis diameter on lung-win-dow images. Nodular shapes were classified as round, ovoid or rectangular, and margins were classified as smooth, lobulated or spiculated. Calcification was classified as stippled, central nodu-lar, laminated or diffuse. Final decisions regarding the morpho-logic features were reached by a consensus.

On the dynamic studies, we measured the nodule attenuation

the lack of fat or calcification makes it difficult to reach a diag-nosis by CT and therefore, invasive techniques, such as percuta-neous needle aspiration, biopsy or surgery, are required to con-firm diagnosis.

Previous studies have shown that dynamic CT could usefully differentiate benign and malignant nodules; moreover, several benign nodules have characteristic hemodynamic features (7). However, although the CT enhancement pattern of pulmonary hamartoma using a single helical CT has been reported (8), to the best of our knowledge, the diagnostic utility of a dynamic multidetector CT (MDCT) for the diagnosis of pulmonary ham-artoma has not been previously described in the English litera-ture. Accordingly, the purpose of this study was to describe the dynamic CT findings of pulmonary hamartoma presenting as a SPN as well as to correlate these findings with the histopatho-logic findings.

MATERIALS AND METHODS

Patients

This retrospective study was approved by our Institutional Re-view Board. We evaluated the morphologic and hemodynamic CT features of 11 patients (M : F = 6 : 5; mean age, 53.6 years; age range, 33-69 years) with surgical biopsy-proven pulmonary ham-artoma who registered at our institute between March 2004 and March 2012. These patients underwent wedge resection (n = 9) and segmentectomy (n = 2). In this study, we included only sur-gical biopsy-proven pulmonary hamartoma in order to correlate its dynamic CT findings with the histopathologic findings.

Nine of the 11 patients were asymptomatic. In these patients, tumors were identified incidentally as SPNs on the chest radio-graphs obtained during routine medical examinations. The oth-er two patients had nonspecific symptoms, such as a mild cough (n = 1) and pleuritic chest pain (n = 1).

Image Analysis

All 11 patients underwent contrast-enhanced helical CT us-ing a 64-dual energy MDCT (Discovery HD 750; GE Health-care, Milwaukee, WI, USA) or a four-row detector (LightSpeed QX/i; GE Healthcare, Milwaukee, WI, USA) scanner. In our in-stitution, dynamic CT scans were routinely preformed with the approval of our institutional review board in patients with non-

Wanglae Cho, et al

451jksronline.org J Korean Soc Radiol 2013;69(6):449-455

lage, loose connective tissue, fat, calcification and slit-like clefts lined with epithelium, were evaluated. The proportions of carti-laginous, loose connective tissue and fat components in whole tumors were automatically quantified with an image analyzer in sections that included the largest plane of tumor tissue.

Statistical Analysis

Statistical analysis was performed using SPSS software (SPSS for Windows, version 11.0, SPSS Inc., Chicago, IL, USA). The re-sults were expressed as mean ± SD for continuous variables. Spearman correlation coefficients were used to evaluate the cor-relation between the extents of CT enhancement and also deter-mined the tumor component percentages. Statistical significance was accepted for p values < 0.05.

RESULTS

The mean tumor long-axis diameter was 14.8 mm (SD, ± 5.8; range, 10-30 mm). Seven (64%) tumors were round and 4 (36%) were ovoid. Six (55%) tumors had smooth margins and 5 (45%) had lobulated margins. Only one tumor (9%) contained an in-tratumoral stippled calcification. Three nodules (27%) had focal areas of negative CT attenuation values, suggesting an intratu-moral fat component.

An enhanced dynamic CT study was feasible for all 11 pa-

values in the same regions on the selected images for each series of images. A circular region of interest (range: 16-200 mm², mean: 60.63 mm²) was placed over the nodule and was made as large as possible. Two radiologists independently measured the atten-uation values, and the two measurements obtained for each nod-ule at each imaging phase by the two radiologists were averaged. Several dynamic characteristics of tumor enhancement were cal-culated, that is; baseline attenuation (AVBase), peak enhancement (PE = attenuation at maximum), net enhancement (NE = PE - AVBase), attenuation value at 15-minutes (AVDelay) and washout value (attenuation difference between PE and AVDelay, WV = PE - AVDelay).

Capsular and septal enhancement of pulmonary hamartoma has been previously reported (8) and therefore, we evaluated the enhancement patterns (homogeneous vs. capsular and septal) and sought to determine the imaging phase that best visualized such enhancement patterns.

Pathologic Comparisons

The intervals between pathologic evaluations and chest CT scans ranged from 10 to 60 days (median, 33 days). A pulmo-nary pathologist (unaware of CT finding) with 19 years of expe-rience in lung pathology evaluated all specimens. With routine light microscopy and hematoxylin and eosin (H&E) staining, the compositions of tumor components, that is, mature carti-

Table 1. Dynamic CT and Histopathologic Characteristics of the 11 Pulmonary Hamartoma

Patient No.

Dynamic CT Characteristics Histopathologic Characteristics

AVBase (HU) PE (HU) AVDelay (HU) NE (HU) WV (HU) Cartilage (%) Connective Tissue (%) Fat (%)

1 10 49 49 39 0 54.97 40.52 4.51 2 24 67 67 43 0 53.21 46.79 0 3 -7 25 25 32 0 60.49 37.14 2.37 4 13 64 64 51 0 46.67 47.31 6.02 5 32 54 54 22 0 76.60 23.40 0 6 54 62 62 8 0 86.36 13.64 0 7 14 53 53 39 0 32.58 51.46 15.96 8 -11 13 13 23 0 68.22 31.78 0 9 41 73 73 32 0 52.07 47.93 010 -10 29 29 36 0 36.54 52.90 10.5511 20 46 46 26 0 67.56 32.44 0

Mean 16.4 48.6 48.6 31.9 0 57.8 38.7 3.58SD 20.9 19.0 19.0 11.8 0 16.3 12.4 5.36

Note.-AVBase = attenuation value at baseline, AVDelay = attenuation value at 15 minutes after commencing injection, HU = Hounsfield unit, NE = net en-hancement (PE - AVBase), PE = peak enhancement, SD = standard deviation, WV = washout value (PE - AVDelay), % = percentages of tissue components in whole tumors

Dynamic CT Findings of Pulmonary Hamartoma

452 jksronline.orgJ Korean Soc Radiol 2013;69(6):449-455

without washout and with a variable degrees of enhancement (range, 8-51 HU) (Figs. 1, 2).

All nodules showed a thick capsular and septal enhancement at different imaging phases [at 60 seconds (n = 1), at 90 seconds (n = 5), at 4 minutes (n = 3), at 5 minutes (n = 2)] (Figs. 1, 2).

tients. Dynamic CT and histopathologic characteristics of 11 cases are summarized in Table 1. For the enhanced dynamic CT studies, the mean AVBase was 16.4 HU (SD, ± 20.9; range, -11-54), mean PE value was 48.6 ± 19.0 HU and mean NE value was 31.9 ± 11.8 HU. All nodules showed a persistent enhancement

Fig. 1. A 39-year-old man (patient 2) with pulmonary hamartoma with persistent (PE, 67 HU; NE, 43 HU) and septal enhancement on dynamic CT.A. Targeted view of a transverse lung window CT scan shows a 13-mm-sized nodule with a lobulated margin in the left upper lobe.B. Targeted view of a transverse mediastinal window CT scan 90 seconds after contrast injection shows peripheral and septal enhancement.C. Sagittal section of an excised specimen in the same patient shows that the tumor consisted of glistening nodules of cartilage separated by clefts.D. Low-magnification photomicrograph shows multiple lobules of mature cartilage intersected by abundant loose connective tissue containing fat and smooth muscle and clefts lined by respiratory epithelium.E. Schema of tumor components, the percentages of cartilaginous component (areas within blue lines) and loose connective tissue components were 53.21% and 46.79%, respectively.Note.-HU = Hounsfield unit, NE = net enhancement, PE = peak enhancement

Fig. 2. A 54-year-old man (patient 6) with pulmonary hamartoma with persistent (PE, 62 HU; NE, 8 HU) and septal enhancement on dynamic CT.A. Targeted view of a transverse mediastinal window CT scan 5 minutes after contrast injection shows peripheral and septal enhancement.B. Low-magnification photomicrograph shows multiple lobules of mature cartilage with intersecting parse loose connective.C. Schema of tumor components, the percentages of cartilaginous component (areas within blue lines) and of loose connective tissue compo-nents were 86.36% and 13.64%, respectively.Note.-HU = Hounsfield unit, NE = net enhancement, PE = peak enhancement

E

B

B

D

A

A

C

C

Wanglae Cho, et al

453jksronline.org J Korean Soc Radiol 2013;69(6):449-455

mors into cartilaginous lobules (less enhancement portion).The persistent enhancement pattern without washout is ob-

served for many benign nodules and may be related to the amount and degree of fibrosis (9-11). Delayed uptake of contrast medi-um may be attributed to contrast redistribution, that is, in the early phase, well-vascularized tumor cell zones show contrast enhancement; however, after contrast medium has moved into the abundant fibrous tissue with scant blood supply during the late phase, it remains in this tissue, and thus, shows an enhance-ment of fibrotic portion of the nodule for a long time without washout. Pathologically, hamartomas of the lung are composed of an abnormal mixture of epithelial and mesenchymal elements, such as cartilage, fat, fibromyxoid tissue, smooth muscle and bone. Therefore, persistent enhancement without washout on dynamic CT scans may be related to abundant fibrous stroma. However, malignant nodules, such as adenocarcinoma, may show persistent enhancement without washout on dynamic CT (7). Therefore, dynamic enhancement patterns do not allow the possibility of lung cancer to be excluded. Potente et al. (8) re-ported septal enhancement in pulmonary hamartoma and cor-related the enhancement patterns with pathologic findings. Twenty-four (80%) of 30 pulmonary hamartomas showed sep-tal enhancement, separating tumors into less dense lobules on dynamic CT images. In the present study, thick septal and cap-sular enhancement was observed in all tumors. The discrepancy between percentages observed in the two studies may be related

All 11 tumors were composed of mature cartilage and loose mesenchymal tissue, which is typical of pulmonary hamartoma. Five tumors had fat components ranging from 2.37% to 15.96%. The percentages of tumor components are summarized in Table 1. Fig. 3 shows the relationship between NE values and patho-logic results. A significant positive correlation was found be-tween the NE values and loose connective tissue component percentages (r = 0.749, p = 0.008), and a negative correlation was found between the NE values and cartilaginous component percentages (r = -0.813, p = 0.002). A comparison of the en-hancement patterns and histopathologic findings revealed that contrast-enhanced septa corresponded to loose connective tis-sue, separating tumors into cartilaginous lobules. Peripheral contrast enhancement was found to correspond to loose con-nective tissue, and not to true capsules.

DISCUSSION

The important observations in this study are summarized as follows: pulmonary hamartoma exhibited a persistent enhance-ment with a variable degree of net enhancement without wash-out and thick capsular and septal enhancements on dynamic CT. NE values were found to be positively correlated with loose con-nective tissue component percentages and thick capsular and septal enhancement was attributed histopathologically to the loose connective tissue (contrast enhanced septa), separating tu-

Fig. 3. Correlation between dynamic CT NE values and pathologic results.A. The correlation between NE values and loose connective tissue component percentages (r = 0.749, p = 0.008).B. The correlation between NE values and cartilage component percentages (r = -0.813, p = 0.002).Note.-HU = Hounsfield unit, NE = net enhancement

A B

8.00 8.00

26.00 26.00

43.00 43.00

39.00 39.00

22.00 22.00

23.00 23.00

36.00 36.00

32.00 32.00

51.00 51.00

Net

enh

ance

men

t (H

U)

Net

enh

ance

men

t (H

U)

10.00 30.00

Connective tissue component (%) Cartilage component (%)

30.00 50.0050.00 80.0020.00 40.0040.00 70.0060.0060.00 90.00

Dynamic CT Findings of Pulmonary Hamartoma

454 jksronline.orgJ Korean Soc Radiol 2013;69(6):449-455

tion, such as popcorn-like calcification or visible fat component, due to relatively high radiation doses. Although we used scan-ning parameters with lower mA, the estimated total lung dose was 4.4 mSv, which is slightly higher than that of standard MDCT. A low-dose technique that presented a lower radiation risk or truncation of the dynamic CT technique would have been more advisable.

In conclusion, hamartoma was found to exhibit persistent en-hancement without wash-out and thick capsular and septal en-hancement by dynamic CT. NE values were found to be positively correlated with loose connective tissue component proportions. Thick capsular and septal enhancement was attributed histopath-ologically to loose connective tissue, which separates tumors into cartilaginous lobules. A follow-up dynamic CT showing persis-tent enhancement with thick capsular and septal enhancement could be helpful in the diagnosis of an ambiguous case of ham-artoma on the initial CT.

REFERENCES

1.GjevreJA,MyersJL,PrakashUB.Pulmonaryhamartomas.

MayoClinProc1996;71:14-20

2.SaqiA,ShahamD,ScognamiglioT,MurrayMP,Henschke

CI,YankelevitzD,etal.Incidenceandcytologicalfeatures

ofpulmonaryhamartomasindeterminateonCTscan.Cy-

topathology2008;19:185-191

3.SedaG,AmundsonD,LinMY.Predominantcartilaginous

hamartoma:anunusualvariantofchondromatousham-

artoma.SouthMedJ2010;103:169-171

4.SwensenSJ,BrownLR,ColbyTV,WeaverAL.Pulmonary

nodules:CTevaluationofenhancementwith iodinated

contrastmaterial.Radiology1995;194:393-398

5.SiegelmanSS,KhouriNF,ScottWWJr,LeoFP,Hamper

UM,FishmanEK,etal.Pulmonaryhamartoma:CTfind-

ings.Radiology1986;160:313-317

6.WhyteRI,DoningtonJS.Hamartomasofthelung.Semin

ThoracCardiovascSurg2003;15:301-304

7.JeongYJ,LeeKS,JeongSY,ChungMJ,ShimSS,KimH,et

al.Solitarypulmonarynodule:characterizationwithcom-

binedwash-inandwashoutfeaturesatdynamicmulti-

detectorrowCT.Radiology2005;237:675-683

8.PotenteG,MacoriF,CaimiM,MingazziniP,VolpinoP.

to the CT units and dynamic CT protocols used. Potente et al. (8) used single helical CT scans and obtained dynamic CT im-ages at 1-minute intervals for up to 3 minutes. However, in the present study, we used multidetector CT scans and obtained dy-namic CT images at detailed intervals for up to 15 minutes. A pathologic comparison study showed that contrast-enhanced septa and capsule corresponded to loose connective tissues, sep-arating tumors into cartilaginous lobules. Park et al. (12) also evaluated cleft-like or septal structures of pulmonary hamarto-ma using magnetic resonance imaging (MRI), and found that all six tumors had cleft-like structures, which were particularly evident on the T2-weighted images. Furthermore, pathological-ly, these structures were found to represent variable mesenchy-mal tissue components arrayed along the respiratory epithelial cells lining the cleft; they show richer vascularity compared to the main portion of pulmonary hamartoma.

Previous studies have reported several radiologic features of hamartoma (1, 5, 8, 13). Characteristic CT findings of hamarto-mas were found to be a lesion of 2.5 cm in diameter or smaller with a smooth margin and focal areas of fat or areas of calcifica-tion (5). The diagnosis of pulmonary hamartoma by CT is heav-ily dependent on the presence of detectable fat or popcorn-like calcifications within lesions. However, many cases fail to exhibit a macroscopic fat component. In the present study, intratumoral fat was observed in only 27% and calcification in only 9% on CT. In these cases, the hemodynamic features of tumors by dy-namic CT can aid the diagnosis. MRI with the chemical-shift technique may also be useful for detecting intracellular lipids in pulmonary hamartomas without definite fat density by CT (14). Although lung MRI has made important progress with respect to speed and image quality in recent years, the technique still has several limitations, such as high susceptibility differences between air spaces and pulmonary interstitium and the pres-ence of respiratory and cardiac motion artifacts, which make it unsuitable for routine clinical use, particularly for the evaluation of small SPNs.

Our study has several limitations. First, due to the rarity of pulmonary hamartoma, the number of cases recruited was too small to prove the power of statistical analysis. Second, the study suffers from selection bias because we only included histopatho-logically proven cases. In addition, dynamic CT scans were not performed in patients with tumors showing benign calcifica-

Wanglae Cho, et al

455jksronline.org J Korean Soc Radiol 2013;69(6):449-455

1230-1237

12.ParkKY,KimSJ,NohTW,ChoSH,LeeDY,PaikHC,etal.

DiagnosticefficacyandcharacteristicfeatureofMRI in

pulmonaryhamartoma:comparisonwithCT, specimen

MRI,andpathology.JComputAssistTomogr2008;32:

919-925

13.PoirierTJ,VanOrdstrandHS.Pulmonarychondromatous

hamartomas.Reportofseventeencasesandreviewofthe

literature.Chest1971;59:50-55

14.HochheggerB,MarchioriE,dosReisDQ,SouzaASJr,Souza

LS,BrumT,etal.Chemical-shiftMRIofpulmonaryhamar-

tomas:initialexperienceusingamodifiedtechniquetoas-

sessnodulefat.AJRAmJRoentgenol2012;199:W331-

W334

Noncalcifiedpulmonaryhamartomas:computedtomog-

raphyenhancementpatternswithhistologiccorrelation.J

ThoracImaging1999;14:101-104

9.MuramatsuY,TakayasuK,MoriyamaN,ShimaY,GotoH,

UshioK,etal.Peripherallow-densityareaofhepatictu-

mors:CT-pathologiccorrelation.Radiology1986;160:49-52

10.TakayasuK,IkeyaS,MukaiK,MuramatsuY,MakuuchiM,

HasegawaH.CTofhilarcholangiocarcinoma:latecontrast

enhancementinsixpatients.AJRAmJRoentgenol1990;

154:1203-1206

11.FurukawaH,TakayasuK,MukaiK,KanaiY, InoueK,Ko-

sugeT,etal.Latecontrast-enhancedCTforsmallpancre-

aticcarcinoma:delayedenhancedareaonCTwithhisto-

pathologicalcorrelation.Hepatogastroenterology1996;43:

폐과오종의 역동적 전산화단층촬영 소견: 조직병리학적 소견과의 비교1

조왕래1 · 정연주1 · 이창훈2 · 이지원1 · 김건일3 · 염정아3 · 김영대4

목적: 단일폐결절로 나타나는 폐과오종의 역동적 전산화단층촬영 소견을 기술하였으며, 이러한 소견을 병리조직학적 소

견과 비교하였다.

대상과 방법: 본 후향적 연구는 임상시험 심사위원회에 승인을 받았으며, 환자의 동의는 생략하였다. 2004년 3월부터

2012년 3월까지, 우리는 수술적으로 확정된 폐과오종 환자 11명(남성 : 여성 = 6 : 5, 평균연령: 53.6세)의 형태학적, 역

동적 전산화단층촬영 소견을 평가하였다. 11명의 모든 환자는 나선식 역동적 전산화단층촬영을 시행받았다(조영제 정맥

주입 후, 0초, 30초, 60초, 90초, 120초 그리고 4분, 5분, 15분 후 결절에 대해 2.5 mm 폭조절로 연속적인 영상을 획득

하였다). 조영증강 정도와 방식을 종양의 조직학적 구성성분과 비교하였다.

결과: 종양의 평균 장축은 14.8 mm, 표준편차는 ± 5.8 mm였다(범위, 10.0~30.0 mm). 6개의 종양은 매끄러운 경계

를 지니고 있었으며, 5개의 종양은 소형상 모양의 경계를 보였다. 전산화단층촬영에서 지방조직과 석회화는 각각 3개, 1

개의 종양에서 관찰되었다. 모든 11개의 종양은 지속적인 조영증강과 다양한 정도의 순조영증강을 보였다[평균 최고 조영

증강은 48.6 ± 19.0 Hounsfield unit (이하 HU); 평균 순조영증강은 31.9 ± 11.8 HU]. 모든 11개의 종양은 성숙된 연

골과 성긴 결합조직성분으로 구성되었다. 5개의 종양이 지방조직을 가지고 있었다. 순조영증강값과 성긴 결합조직 성분의

비율 간에 유의한 양의 상관관계를 보였으며, 순조영증강값과 연골 조직 비율 간의 음의 상관관계를 보였다.

결론: 역동적 전산화단층촬영에서, 과오종은 모든 경우에서 지속적인 조영증강과 다양한 정도의 순조영증강 그리고 두꺼

운 피막 및 격막 조영증강을 보였다. 순조영증강값은 성긴 결합조직 비율과 양의 상관관계를 보였으며, 두꺼운 피막 및 격

막 조영증강은 종양의 연골 소엽을 나누는 성긴 결합조직(조영증강된 격막)으로부터 기인하는 것으로 판단된다.

부산대학교 의과대학 부산대학교병원 1영상의학과, 2병리과, 4흉부외과, 3부산대학교 의과대학 양산부산대학교병원 영상의학과