Pulmonary tuberculosis occurred in patient with Tracheobronchopathia Osteochondroplastica / 고신대학교의과대학학술지

Tracheobronchopathia osteoplastica (TO) is a rare benign disease in which the anterior inner wall of the tracheobronchus changes because of abnormal chondrogenesis or ossification, while the posterior wall of the trachea is spared. The etiology is not clearly understood, but may relate with chronic infection, inflammation, and trauma. In some case studies, it has also been reported to be accompanied by other chronic diseases such as atrophic rhinitis and amyloidosis. However, Coexistence of TO and tuberculosis has rarely been reported, and has never been reported in Korea. Here, we report a case of a 70-year-old male patient who complained of hemoptysis and whose case was diagnosed as TO and pulmonary tuberculosis through bronchoscopy with bronchial washing and biopsy.

Cardiac Metastasis of Leiomyosarcoma Complicated with Complete Atrio-Ventricular Block and Ventricular Tachycardia

We described a case of a 54-year-old male who presented with dizziness and dyspnea due to cardiac metastasis of leiomyosarcoma. Cardiac metastasis of leiomyosarcoma caused both bradyarrhythmia and tachyarrhythmia in the patient. He was treated with implantation of a permanent pacemaker for management of complete atrio-ventricular block and anti-arrhythmic drug that suppressed ventricular tachycardia successfully.

Comparison of Iohexol-380 and Iohexol-350 for Coronary CT Angiography: A Multicenter, Randomized, Double-Blind Phase 3 Trial

OBJECTIVE: This multi-center, randomized, double-blind, phase 3 trial was conducted to compare the safety and efficacy of contrast agents iohexol-380 and iohexol-350 for coronary CT angiography in healthy subjects. MATERIALS AND METHODS: Volunteers were randomized to receive 420 mgI/kg of either iohexol-350 or iohexol-380 using a flow rate of 4 mL/sec. All adverse events were recorded. Two blinded readers independently reviewed the CT images and conflicting results were resolved by a third reader. Luminal attenuations (ascending aorta, left main coronary artery, and left ventricle) in Hounsfield units (HUs) and image quality on a 4-point scale were calculated. RESULTS: A total of 225 subjects were given contrast media (115 with iohexol-380 and 110 with iohexol-350). There was no difference in number of adverse drug reactions between groups: 75 events in 56 (48.7%) of 115 subjects in the iohexol-380 group vs. 74 events in 51 (46.4%) of 110 subjects in the iohexol-350 group (p = 0.690). No severe adverse drug reactions were recorded. Neither group showed an increase in serum creatinine. Significant differences in mean density between the groups was found in the ascending aorta: 375.8 ± 71.4 HU with iohexol-380 vs. 356.3 ± 61.5 HU with iohexol-350 (p = 0.030). No significant differences in image quality scores between both groups were observed for all three anatomic evaluations (all, p > 0.05). CONCLUSION: Iohexol-380 provides improved enhancement of the ascending aorta and similar attenuation of the coronary arteries without any increase in adverse drug reactions, as compared with iohexol-350 using an identical amount of total iodine.

A Case of Primary Subpleural Pulmonary Microcystic Myxoma Coincidentally Occurred with Pulmonary Adenocarcinoma

No abstract available.

A Case of Pneumonia Caused by Pneumocystis jirovecii Resistant to Trimethoprim-Sulfamethoxazole

A 50-year-old male visited the outpatient clinic and complained of fever, poor oral intake, and weight loss. A chest X-ray demonstrated streaky and fibrotic lesions in both lungs, and chest CT revealed multifocal peribronchial patchy ground-glass opacities with septated cystic lesions in both lungs. Cell counts in the bronchoalveolar lavage fluid revealed lymphocyte-dominant leukocytosis, and further analysis of lymphocyte subsets showed a predominance of cytotoxic T cells and few T helper cells. Video-assisted wedge resection of the left upper lobe was performed, and the histologic examination was indicative of a Pneumocystis jirovecii infection. Trimethoprim-sulfamethoxazole (TMP-SMX) was orally administered for 3 weeks; however, the patient complained of cough, and the pneumonia was aggravated in the follow-up chest X-ray and chest CT. Molecular studies demonstrated mutations at codons 55 and 57 of the dihydropteroate synthase (DHPS) gene, which is associated with the resistance to TMP-SMX. Clindamycin-primaquine was subsequently administered for 3 weeks replacing the TMP-SMX. A follow-up chest X-ray showed that the pneumonia was resolving, and the cough was also alleviated. A positive result of HIV immunoassay and elevated titer of HCV RNA indicated HIV infection as an underlying condition. This case highlights the importance of careful monitoring of patients with P. jirovecii pneumonia (PCP) during the course of treatment, and the molecular study of DHPS mutations. Additionally, altering the anti-PCP drug utilized as treatment must be considered when infection with drug-resistant P. jirovecii is suspected. To the best of our knowledge, this is the first case of TMP-SMX-resistant PCP described in Korea.

Annual Change in Pulmonary Function and Clinical Characteristics of Combined Pulmonary Fibrosis and Emphysema and Idiopathic Pulmonary Fibrosis: Over a 3-Year Follow-up / 결핵및호흡기질환

BACKGROUND: Combined pulmonary fibrosis and emphysema (CPFE) have different pulmonary function tests (PFTs) and outcomes than idiopathic pulmonary fibrosis (IPF). The intention of this study was to identify unknown differences between CPFE and IPF by a retrospective comparison of clinical data including baseline and annual changes in pulmonary function, comorbidities, laboratory findings, clinical characteristics and cause of hospitalization. METHODS: This study retrospectively enrolled patients with CPFE and IPF who had undergone PFTs once or several times per year during a follow-up period of three years. Baseline clinical characteristics and the annual changes in the pulmonary function during the follow-up period were compared between 26 with CPFE and 42 patients with IPF. RESULTS: The baseline ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC%) in patients with CPFE was lower than that in patients with IPF (78.6+/-1.7 vs. 82.9+/-1.1, p=0.041). The annual decrease in FEV1/FVC in the CPFE was significantly higher than in the IPF. The annual decreases in diffusion capacity of carbon monoxide and FVC showed no significant differences between the two groups. The symptom durations of cough and sputum were in the CPFE significantly lower than in the IPF. The serum erythrocyte sedimentation rate level at the acute stage was significantly higher than in the IPF. There were no significant differences in the hospitalization rate and pneumonia was the most common cause of hospitalization in both study groups. CONCLUSION: The annual decrease of FEV1/FVC was in patients with CPFE significantly higher than in the patients with IPF.

Annual Change in Pulmonary Function and Clinical Characteristics of Combined Pulmonary Fibrosis and Emphysema and Idiopathic Pulmonary Fibrosis: Over a 3-Year Follow-up / 결핵및호흡기질환

BACKGROUND: Combined pulmonary fibrosis and emphysema (CPFE) have different pulmonary function tests (PFTs) and outcomes than idiopathic pulmonary fibrosis (IPF). The intention of this study was to identify unknown differences between CPFE and IPF by a retrospective comparison of clinical data including baseline and annual changes in pulmonary function, comorbidities, laboratory findings, clinical characteristics and cause of hospitalization. METHODS: This study retrospectively enrolled patients with CPFE and IPF who had undergone PFTs once or several times per year during a follow-up period of three years. Baseline clinical characteristics and the annual changes in the pulmonary function during the follow-up period were compared between 26 with CPFE and 42 patients with IPF. RESULTS: The baseline ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC%) in patients with CPFE was lower than that in patients with IPF (78.6+/-1.7 vs. 82.9+/-1.1, p=0.041). The annual decrease in FEV1/FVC in the CPFE was significantly higher than in the IPF. The annual decreases in diffusion capacity of carbon monoxide and FVC showed no significant differences between the two groups. The symptom durations of cough and sputum were in the CPFE significantly lower than in the IPF. The serum erythrocyte sedimentation rate level at the acute stage was significantly higher than in the IPF. There were no significant differences in the hospitalization rate and pneumonia was the most common cause of hospitalization in both study groups. CONCLUSION: The annual decrease of FEV1/FVC was in patients with CPFE significantly higher than in the patients with IPF.

The Relationship between Coronary Artery Calcification and Renal Function in Nondialyzed Patients

PURPOSE: Coronary artery calcification (CAC) has been described in individuals with chronic kidney disease (CKD), and its presence is associated with an increased risk of cardiovascular death. However, it is unclear whether there is an independent relationship between renal function and CAC. Therefore, we evaluated the association between renal function and CAC. MATERIALS AND METHODS: We retrospectively reviewed 870 Korean patients who had undergone computed tomographic coronary angiography. The glomerular filtration rate (GFR) was estimated using the Modification of Diet in Renal Disease study formula with an ethnic factor for the Korean population. The CKD stages were classified using estimated GFR (eGFR) and proteinuria. RESULTS: The mean age of the participants was 56.8+/-11.8 years, and the mean eGFR was 89.4+/-16.5 mL/min/1.73 m2. Hypertension and diabetes were noted in 41.5 and 17.0% of patients, respectively. There were 584 and 286 patients with no CAC and with CAC, respectively. After adjusting for confounding variables, late stage CKD was associated with CAC [odds ratio (OR) 2.80, 95% confidence interval (CI) 1.05-7.46]. However, early stage CKD was not associated with CAC (OR 1.61, 95% CI 0.92-2.82). Diabetes was an independent risk factor of CAC (OR 2.06, 95% CI 1.36-3.13). There was no significant association between proteinuria and CAC (OR 1.65, 95% CI 0.96-2.85). CONCLUSION: CAC is related to late stage CKD in nondialyzed patients. These findings emphasize that individuals with CAC should be considered a high-risk population for decreased renal function.

A Paragonimiasis Patient with Allergic Reaction to Praziquantel and Resistance to Triclabendazole: Successful Treatment after Desensitization to Praziquantel

Paragonimiasis is an infectious disease caused by trematodes of the genus Paragonimus. This trematode can be treated successfully with praziquantel in more than 90% of the cases. Although praziquantel is generally well tolerated, anaphylactic reactions to this drug have been reported in a few cases. We report here a 46-year-old Korean female with paragonimiasis, presumed to be due to Paragonimus westermani, who displayed an allergic reaction to praziquantel and resistance to triclabendazole treatment. The patient was successfully treated with praziquantel following a rapid desensitization procedure. Desensitization to praziquantel could be considered when no alternative drugs are available.

Concurrent renal and hepatic angiomyolipoma with pulmonary involvement in two patients with tuberous sclerosis / 대한내과학회지

Tuberous sclerosis (TS) involves multiple organs. Angiomyolipoma of the liver or kidney is one of the clinical manifestations of TS. However, coexistent renal and hepatic angiomyolipoma associated with TS is a rare condition. Pulmonary involvement is extremely rare, and occurs in only 0.1~1% of TS. We report two cases of concurrent renal and hepatic angiomyolipomas with pulmonary involvement in patients with TS. The first case was a 35 year-old woman who showed multiple angiomyolipomas in the liver and both kidneys and cystic parenchymal changes in the lungs. The other case was a 27-year-old woman who showed multiple angiomyolipomas in the liver and both kidneys, and multinodular pulmonary shadows. To the best of our knowledge, this is the first reported case of renal and hepatic angiomyolipomas associated with pulmonary involvement in Korea.

A Case of Papillary Adenocarcinoma Presenting with Multiple Cysts / 결핵및호흡기질환

A 23-year old woman was admitted to our hospital with hemoptysis. The chest X-ray showed reticulonodular opacity and multiple cysts throughout the entire lung field. The chest CT scan revealed numerous bilateral cysts with various sizes, some of them with thickened walls. An open lung wedge resection was performed. The resected specimen showed scattered small nodules, 0.3 to 0.6 cm in size. Microscopically, each nodule was composed of atypical glands with an occasional papillary architecture spreading to the alveolar septa, which were morphologically consistent with a papillary adenocarcinoma with a bronchioloalveolar carcinoma growth pattern. Immunochemically, the tumor cells were negative for the S-100 protein. The patient was diagnosed with an adenocarcinoma of the lung. A variety of diseases can produce or mimic multiple, thin-walled cysts in the lung. Lung cancer with multiple cysts is quite rare. Nevertheless, adenocarcinoma should be a diagnostic consideration. We report a case of a multiple cystic adenocarcinoma of the lung.

(18)F-FDG PET versus (18)F-FDG PET/CT for Adrenal Gland Lesion Characterization: a Comparison of Diagnostic Efficacy in Lung Cancer Patients

OBJECTIVE: The aim of this study was to assess the diagnostic efficacy of integrated PET/CT using fluorodeoxyglucose (FDG) for the differentiation of benign and metastatic adrenal gland lesions in patients with lung cancer and to compare the diagnostic efficacy with the use of PET alone. MATERIALS AND METHODS: Sixty-one adrenal lesions (size range, 5-104 mm; mean size, 16 mm) were evaluated retrospectively in 42 lung cancer patients. Both PET images alone and integrated PET/CT images were assessed, respectively, at two-month intervals. PET findings were interpreted as positive if the FDG uptake of adrenal lesions was greater than or equal to that of the liver, and the PET/CT findings were interpreted as positive if an adrenal lesion show attenuation > 10 HU and showed increased FDG uptake. Final diagnoses of adrenal gland lesions were made at clinical follow-up (n = 52) or by a biopsy (n = 9) when available. The diagnostic accuracies of PET and PET/CT for the characterization of adrenal lesions were compared using the McNemar test. RESULTS: Thirty-five (57%) of the 61 adrenal lesions were metastatic and the remaining 26 lesions were benign. For the depiction of adrenal gland metastasis, the sensitivity, specificity, and accuracy of PET were 74%, 73%, and 74%, respectively, whereas those of integrated PET/CT were 80%, 89%, and 84%, respectively (p values; 0.5, 0.125, and 0.031, respectively). CONCLUSION: The use of integrated PET/CT is more accurate than the use of PET alone for differentiating benign and metastatic adrenal gland lesions in lung cancer patients.

The "Mini-Perc" Technique of Percutaneous Nephrolithotomy with a 14-Fr Peel-away Sheath: 3-year Results in 72 Patients

OBJECTIVE: To assess the efficacy and safety of a "mini-perc" technique of percutaneous nephrolithotomy using a 14-Fr peel-away sheath for the removal of pyelocaliceal stones, and to determine appropriate inclusion criteria. MATERIALS AND METHODS: From July 1999 to June 2002, the medical records and radiographic images of 72 patients who underwent the "mini-perc" technique of percutaneous nephrolithotomy with a 14-Fr peel-away sheath, were reviewed to determine clinical history, stone characteristics, immediate stone free rate, final stone free rate after additional procedures, complications, and hospital stay. We also analyzed the effect of the longest stone diameter, the cumulative longest diameter of stones, the cumulative stone burden, and the stone density on the immediate stone free rate using a Fisher exact test. RESULTS: The only major complication, arterial bleeding, occurred in a patient with Child A liver cirrhosis and was successfully treated by embolization with coils and a gelatin sponge. The immediate stone free rate was 80.6 %, which was significantly influenced by stone diameter but not stone density. The mean hospital stay after the procedure was 3.97 days. CONCLUSION: The "mini-perc" technique of percutaneous nephrolithotomy, which uses the 14-Fr peel-away sheath, is a safe and effective modality for treating renal calculi.

The Balloon Dilatation and Large Profile Catheter Maintenance Method for the Management of the Bile Duct Stricture Following Liver Transplantation

OBJECTIVE: We wanted to evaluate the therapeutic efficacy of the percutaneous balloon dilatation and large profile catheter maintenance method for the management of patients with anastomotic biliary strictures following liver transplant. MATERIALS AND METHODS: From May 1999 to June 2003, 12 patients with symptomatic benign biliary stricture complicated by liver transplantation were treated with the percutaneous balloon dilatation and large profile catheter maintenance method (1-6 months). The patients were eight males and four females, and their ages ranged from 20 to 62 years (mean age: 44 years). Ten patients underwent living donor liver transplantation and two underwent cadaveric liver transplantation. Postoperative biliary strictures occurred from two to 21 months (mean age: 18 months) after liver transplantation. RESULTS: The initial technical success rate was 92%. Patency of the bile duct was preserved for eight to 40 months (mean period: 19 months) in 10 of 12 (84%) patients. When reviewing two patients (17%), secondary balloon dilatations were needed for treating the delayed recurrence of biliary stricture. In one patient, no recurrent stenosis was seen during the further 10 months follow-up after secondary balloon dilatation. Another patient did not response to secondary balloon dilatation, and he was treated by surgery. Eleven of 12 patients (92%) showed good biliary patency for 8-40 months (mean period: 19 months) of follow-up. CONCLUSION: The percutaneous balloon dilatation and large profile catheter maintenance method is an effective therapeutic alternative for the treatment of most biliary strictures that complicate liver transplantation. It has a high success rate and it should be considered before surgery.

1024 Matrix Image Reconstruction: Usefulness in High Resolution chest CT

PURPOSE: We tried to evaluate whether high resolution chest CT with a 1,024 matrix has a significant advantage in image quality compared to a 512 matrix. MATERIALS AND METHODS: Each set of 512 and 1024 matrix high resolution chest CT scans with both 0.625 mm and 1.25 mm slice thickness were obtained from 26 patients. Seventy locations that contained twenty-four low density lesions without sharp boundary such as emphysema, and forty-six sharp linear densities such as linear fibrosis were selected; these were randomly displayed on a five mega pixel LCD monitor. All the images were masked for information concerning the matrix size and slice thickness. Two chest radiologists scored the image quality of each arrowed lesion as follows: (1) undistinguishable, (2) poorly distinguishable, (3) fairly distinguishable, (4) well visible and (5) excellently visible. The scores were compared from the the aspects of matrix size, slice thickness and the different observers by using ANOVA tests. RESULTS: The average and standard deviation of image quality were 3.09 (+/-.92) for the 0.625 mmx512 matrix, 3.16 (+/-.84) for the 0.625 mmx1024 matrix, 2.49 (+/-1.02) for the 1.25 mmx512 matrix, and 2.35 (+/-1.02) for the 1.25 mmx1024 matrix, respectively. The image quality on both matrices of the high resolution chest CT scans with a 0.625 mm slice thickness was significantly better than that on the 1.25 mm slice thickness (p < 0.001). However, the image quality on the 1024 matrix high resolution chest CT scans was not significantly different from that on the 512 matrix high resolution chest CT scans (p = 0.678). The interobserver variation between the two observers was not significant (p = 0.691). CONCLUSION: We think that 1024 matrix image reconstruction for high resolution chest CT may not be clinically useful.

Long-term Results of Percutaneous Ethanol Injection for the Treatment of Hepatocellular Carcinoma in Korea

OBJECTIVE: To evaluate the long-term follow-up results of percutaneous ethanol injection (PEI) for the treatment of hepatocellular carcinoma (HCC) in Korea. MATERIALS AND METHODS: Sixty-eight nodular HCCs initially detected in 64 patients, were subjected to US-guided PEI as a first-line treatment. Long-term survival rates, local tumor progression rates, and complications were evaluated, as were the influences of tumor size and Child-Pugh class on these variables. RESULTS: No major complications occurred. The overall survival rates of the 64 patients at three and five years were 71% and 39%, and their cancer-free survival rates were 22% and 15%, respectively. The overall survival rate of patients with a small HCC (< or = 2 cm) was significantly higher (p = 0.014) than that of patients with a medium-sized HCC (< or = 2 cm). The overall survival rate of patients with Child-Pugh class A was significantly higher (p = 0.049) than that of patients with Child-Pugh class B. Of 59 cases with no residual tumor, local tumor progression was observed in ablation zones in 18, and this was not found to be significantly influenced by tumor size or Child-Pugh class. CONCLUSION: The results of our investigation of the long-term survival rates of PEI in HCC patients in Korea (a hepatitis B virus-endemic area) were consistent with those reported previously in hepatitis C endemic areas. Patients with a smaller tumor or a better liver function exhibited superior survival rates.

Usefulness of Multidetector-row CT in the Evaluation of Reperfused Myocardial Infarction in a Rabbit Model

OBJECTIVE: To evaluate the usefulness of multidetector-row computed tomography (CT) in the evaluation of reperfused myocardial infarction. MATERIALS AND METHODS: Eleven rabbits were subjected to 90-min occlusion of the left anterior descending coronary artery followed by reperfusion. Multidetector-row CT was performed 31 hours+/-21 after the procedure and preand post-contrast multiphase helical CT images were obtained up to 10 min after contrast injection. The animals were sacrificed after 30 days and histochemical staining of the resected specimens was perfomed with 2'3'5-triphenyl tetrazolium chloride (TTC). RESULTS: In all 11 cases, the areas of myocardial infarction demonstrated with TTC-staining were identified on the CT images and the lesions showed hypoenhancement on the early phases up to 62 sec and hyperenhancement on the delayed phases of 5 min and 10 min compared with normal myocardial enhancement. The percentage area of the lesion with respect to the left ventricle wall on CT was significantly correlated with that of the TTC-staining results (p < 0.001 for both early and delayed phase CT) according to the generalized linear model analysis. The areas showing hypoenhancement on early CT were significantly smaller than those with hyperenhancement on delayed CT (p < 0.0001). CONCLUSION: Multidetector-row CT may be useful in the detection and sizing of reperfused myocardial infarction.

Radiofrequency Ablation of Rabbit Liver In Vivo: Effect of the Pringle Maneuver on Pathologic Changes in Liver Surrounding the Ablation Zone

OBJECTIVE: We wished to evaluate the effect of the Pringle maneuver (occlusion of both the hepatic artery and portal vein) on the pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone in rabbit livers. MATERIALS AND METHODS: Radiofrequency (RF) ablation zones were created in the livers of 24 rabbits in vivo by using a 50-W, 480-kHz monopolar RF generator and a 15-gauge expandable electrode with four sharp prongs for 7 mins. The tips of the electrodes were placed in the liver parenchyma near the porta hepatis with the distal 1 cm of their prongs deployed. Radiofrequency ablation was performed in the groups with (n=12 rabbits) and without (n=12 rabbits) the Pringle maneuver. Three animals of each group were sacrificed immediately, three days (the acute phase), seven days (the early subacute phase) and two weeks (the late subacute phase) after RF ablation. The ablation zones were excised and serial pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone were evaluated. RESULTS: With the Pringle maneuver, portal vein thrombosis was found in three cases (in the immediate [n=2] and acute phase [n=1]), bile duct dilatation adjacent to the ablation zone was found in one case (in the late subacute phase [n=1]), infarction adjacent to the ablation zone was found in three cases (in the early subacute [n=2] and late subacute [n=1] phases). None of the above changes was found in the livers ablated without the Pringle maneuver. On the microscopic findings, centrilobular congestion, sinusoidal congestion, sinusoidal platelet and neutrophilic adhesion, and hepatocyte vacuolar and ballooning changes in liver ablated with Pringle maneuver showed more significant changes than in those livers ablated without the Pringle maneuver (p < 0.05) CONCLUSION: Radiofrequency ablation with the Pringle maneuver created more severe pathologic changes in the portal vein, bile ducts and liver parenchyma surrounding the ablation zone compared with RF ablation without the Pringle maneuver. Therefore, we suggest that RF ablation with the Pringle maneuver should be performed with great caution in order to avoid unwanted thermal injury.

Selective Intra-Arterial Calcium Stimulation with Hepatic Venous Sampling for Preoperative Localization of Insulinomas

OBJECTIVE: To determine the value of selective intra-arterial calcium stimulation with hepatic venous sampling using serum insulin and C-peptide gradients for the preoperative localization of insulinomas. MATERIALS AND METHODS: Seven consecutive patients [three men and four women aged 15-77 (mean, 42.7) years] with hypoglycemia underwent selective intra-arterial calcium stimulation in conjunction with hepatic venous sampling. Insulin gradients were calculated by an individual blinded to all other preoperative imaging studies and operative findings. In all patients except one, C-peptide gradients were also analyzed. The results were compared with the preoperative findings of ultrasonography, computed tomography, arteriography and endoscopic ultrasonography, as well as with the intraoperative findings of ultrasonography and palpation at surgery. RESULTS: Eight insulinomas (mean diameter, 12.5 mm) were diagnosed after surgery. In six patients, the calcium stimulation test with insulin gradients allowed accurate localization of the pathologic source of insulin secretion. Both C-peptide and insulin gradients substantially increased diagnostic accuracy. In one patient, C-peptide gradients were more helpful than insulin gradients for tumor localization. CONCLUSION: Selective intra-arterial calcium stimulation with hepatic venous sampling is a highly accurate and safe method for the preoperative localization of insulinomas. Additional C-peptide gradients seem to be helpful in assessing tumor location, but further study is needed.

"Aorta-in-Aorta" Sign on Chest Radiograph Representing Enlarged Left Superior Intercostal and Hemiazygos Veins

We recently encountered a patient with membranous obstruction of the inferior vena cava in whom the left superior intercostal and hemiazygos veins were dilated. At chest radiography, the dilation simulated the presence of a second aortic knob and descending thoracic aorta lateral to the originals, and an "aorta-in-aorta" appearance was thus created.