Pulmonary involvement with Erdheim-Chester disease: radiographic and CT findings

OBJECTIVE

We determined the chest radiographic and CT findings of Erdheim-Chester disease with pulmonary involvement.

MATERIALS AND METHODS

We retrospectively reviewed the radiologic images of 15 patients with biopsy-proven Erdheim-Chester disease. Nine patients had chest radiographic images and CT scans that were available for review. Six men and three women were studied (age range, 25-70 years; mean age, 56 years). Two radiologists interpreted all images by consensus. Lung parenchyma was assessed for the type and distribution of disease. Bronchi, pleurae, hila, and mediastinal and extrathoracic structures were evaluated for abnormalities. Pathologic specimens from all patients were reviewed and correlated with radiologic findings.

RESULTS

Eight of nine patients had thoracic images with abnormal findings. The most common radiographic pattern was reticular interstitial opacities with fissural and interlobular septal thickening. CT revealed regions of ground-glass attenuation and centrilobular nodular opacities. Typically, extrapulmonary findings included pleural effusions (6/8 patients), pericardial fluid or thickening (4/8), and extrathoracic infiltrative soft-tissue masses (4/8).

CONCLUSION

The most common findings of Erdheim-Chester disease with pulmonary involvement include an interstitial process characterized by smooth interlobular septal thickening and centrilobular nodular opacities, fissural thickening, and pleural effusions. On CT, six of nine patients had pericardial fluid and thickening or extrathoracic soft-tissue masses. Such findings are characteristic of Erdheim-Chester disease with pulmonary involvement. Definitive diagnosis requires correlating skeletal findings and lung biopsy findings.

Lung nodule enhancement at CT: multicenter study

PURPOSE

To test the hypothesis that absence of statistically significant lung nodule enhancement (< or =15 HU) at computed tomography (CT) is strongly predictive of benignity.

MATERIALS AND METHODS

Five hundred fifty lung nodules were studied. Of these, 356 met all entrance criteria and had a diagnosis. On nonenhanced, thin-section CT scans, the nodules were solid, 5-40 mm in diameter, relatively spherical, homogeneous, and without calcification or fat. All patients were examined with 3-mm-collimation CT before and after intravenous injection of contrast material. CT scans through the nodule were obtained at 1, 2, 3, and 4 minutes after the onset of injection. Peak net nodule enhancement and time-attenuation curves were analyzed. Seven centers participated.

RESULTS

The prevalence of malignancy was 48% (171 of 356 nodules). Malignant neoplasms enhanced (median, 38.1 HU; range, 14.0-165.3 HU) significantly more than granulomas and benign neoplasms (median, 10.0 HU; range, -20.0 to 96.0 HU; P < .001). With 15 HU as the threshold, the sensitivity was 98% (167 of 171 malignant nodules), the specificity was 58% (107 of 185 benign nodules), and the accuracy was 77% (274 of 356 nodules).

CONCLUSION

Absence of significant lung nodule enhancement (< or = 15 HU) at CT is strongly predictive of benignity.

Lung nodules: dual-kilovolt peak analysis with CT--multicenter study

PURPOSE

To test the following hypothesis: The greater the increase in the mean computed tomographic (CT) number of a radiologically indeterminate lung nodule from the CT number on a 140-kVp CT image to that on an 80-kVp CT image, the more likely the nodule is benign (ie, contains calcium).

MATERIALS AND METHODS

Two hundred forty indeterminate lung nodules were prospectively studied at four institutions: Mayo Clinic Scottsdale, Ariz (n = 160); Mayo Clinic Rochester, Minn (n = 50); Shiga Health Insurance Hospital, Otsu, Japan (n = 25); and Duke University Medical Center, Durham, NC (n = 5). Of the 240 nodules, 157 met the entrance criteria for this study and had a diagnosis. All nodules included were solid, 5-40-mm diameter, relatively spherical, homogeneous, and without visible evidence of calcification or fat. Each nodule was evaluated by using 3-mm-collimation, nonenhanced CT scans with both 140- and 80-kVp x-ray beams.

RESULTS

There were 86 (55%) benign and 71 (45%) malignant nodules. The median increase in the nodule mean CT number from the CT number on 140-kVp images to that on 80-kVp images was 2 HU for benign nodules and 3 HU for malignant nodules. This difference was not statistically significant. The area under the receiver operating characteristic curve was 0.505.

CONCLUSION

Dual-kilovolt peak analysis with current CT technology does not appear to be helpful in the identification of benign lung nodules.

Radiologic findings of bronchogenic carcinoma with pulmonary metastases at presentation

PURPOSE

To describe the radiologic findings in patients with primary bronchogenic carcinoma and pulmonary metastases at presentation.

MATERIALS AND METHODS

A retrospective review of patients with bronchogenic carcinoma who at presentation had pulmonary metastases.

RESULTS

Fourteen (52%) men and 13 (48%) women with a mean age of 60 years were identified. Adenocarcinoma was the most common histology (70%). The number of nodules varied, although 78% of patients had greater than 50 nodules. Nodules size ranged from 2 to 30 mm, but 82% of patients had nodules less than 10 mm in diameter. Mediastinal lymphadenopathy was seen in 41% of patients, and pleural disease in 44% of patients. Only 37% had radiologic evidence of extrathoracic disease, with bone metastases (30%) being the most common.

CONCLUSION

Multiple pulmonary nodules may be the presenting thoracic manifestation of primary bronchogenic carcinoma, with patterns of metastases and survival rates similar to other stage IV patients.

Suspected non-small cell lung cancer: incidence of occult brain and skeletal metastases and effectiveness of imaging for detection--pilot study

PURPOSE

To estimate the incidence of occult metastases to the brain and skeleton in patients suspected of having non-small cell lung cancer (NSCLC) (stage higher than T1Nomo) with surgically resectable disease, to assess the accuracy of screening magnetic resonance (MR) imaging and radionuclide bone scanning for help in identifying occult metastases, and to determine the effectiveness of a high dose of MR contrast material.

MATERIALS AND METHODS

Twenty-nine patients suspected of having NSCLC localized to the lung or to the lung and regional nodes underwent preoperative MR imaging with contrast material enhancement and radionuclide bone scanning for detection of brain or skeletal metastases. Patients were followed up for 12 months to determine the incidence of clinical metastatic disease.

RESULTS

Eight (28%) patients had occult metastatic disease to the brain or skeleton. Brain metastases were identified on MR images in five of six patients. Bone metastases were identified on MR images in four of five patients and on bone scans in three of five patients. MR imaging was no more accurate than bone scanning for skeletal evaluation. A high dose of MR contrast material allowed detection of more metastases and of small lesions.

CONCLUSION

Contrast-enhanced MR imaging of the brain is indicated for the exclusion of brain metastases in patients with clinically operable known or possible NSCLC and a large (> 3-cm) lung mass. Skeletal imaging may be indicated if an isolated brain metastasis is detected.

Solitary pulmonary nodules: clinical prediction model versus physicians

OBJECTIVE

To determine whether a clinical prediction model developed to identify malignant lung nodules based on clinical data and radiologic lung nodule characteristics could predict a malignant lung nodule diagnosis with higher accuracy than physicians.

MATERIAL AND METHODS

One hundred cases were obtained by using a stratified random sample from a retrospective cohort of 629 patients with newly discovered 4- to 30-mm radiologically indeterminate solitary pulmonary nodules (SPNs) on chest radiography. A chest radiologist, pulmonologist, thoracic surgeon, and general internist made predictions of a malignant lesion and recommendations for management (thoracotomy, transthoracic needle aspiration biopsy, or observation) on the basis of radiologic and clinical data used to develop the clinical prediction rule. The predictions of a malignant lung nodule were compared with the probability of malignant involvement from a previously validated clinical prediction model to identify malignant nodules on the basis of three clinical characteristics (age, smoking status, and history of cancer greater than or equal to 5 years previously) and three radiologic characteristics (nodule diameter, spiculation, and upper lobe location).

RESULTS

Receiver operating characteristic analysis showed no significant difference between the logistic model and the physicians' predictions. Calibration curves revealed that physicians overestimated the probability of a malignant lesion in patients with low risk of malignant disease by the prediction rule; this finding suggests a potential for the decision rule to improve the management of patients with SPNs that are likely to be benign.

CONCLUSION

The prediction model was not better than physicians' predictions of malignant SPNs. The prediction rule may have potential to improve the management of patients with SPNs that are likely to be benign.

Erdheim-Chester disease: clinical, radiologic, and histopathologic findings in five patients with interstitial lung disease

Erdheim-Chester disease is a clinicopathologic entity defined by a characteristic pattern of symmetric osteosclerosis caused by an infiltrate of mononuclear cells that include prominent numbers of foamy histiocytes. About half of patients have extraskeletal manifestations, including involvement of the hypothalamus/posterior pituitary, orbit, retroperitoneum, skin, lung, and heart. Pulmonary involvement is an uncommon but important manifestation of Erdheim-Chester disease because it causes significant morbidity and mortality. A review of the Mayo Clinic files produced four patients with confirmed Erdheim-Chester disease in whom lung biopsy had been performed. One additional patient was included from the University of Pittsburgh. Four patients were women. The mean age was 53.6 years (range 25-70 years). All patients had bilateral and symmetric sclerotic bone lesions characteristic of Erdheim-Chester disease, although in three the skeletal abnormalities were discovered only after lung biopsy. Four patients had dyspnea, and one also had a dry cough. One patient died 17 months after diagnosis. Chest radiographs showed diffuse interstitial infiltrates in all patients, with an upper zone predominance in three. Thoracic computed tomography (CT) scans showed thickening of the visceral pleura and interlobular septa with patchy associated fine reticular and centrilobular opacities and ground glass attenuation. Lung biopsy specimens showed an infiltrate of foamy histiocytes, lymphocytes, and scattered Touton giant cells with associated fibrosis in a striking lymphatic distribution. The infiltrate involved visceral pleura, interlobular septa, and bronchovascular bundles. Immunohistochemical stains were positive for CD68 in all cases and S-100 protein in four cases. Stains for CD1a were consistently negative. Ultrastructural studies in one case showed no Birbeck granules. Although in bone the histologic features of Erdheim-Chester disease may overlap with Langerhans' cell histiocytosis, its expression in the lung is distinct. Lung involvement in Erdheim-Chester disease has emerged as a unique radiographic and histologic entity.

Colchicine versus prednisone in the treatment of idiopathic pulmonary fibrosis. A randomized prospective study. Members of the Lung Study Group

Twenty-six symptomatic subjects with clinical evidence plus either high-resolution computed tomography (HRCT, n = 25) or open-lung biopsy (OLB, n = 1) patterns typical for idiopathic usual interstitial pneumonia (idiopathic UIP) were entered into a randomized prospective treatment trial using high-dose prednisone (n = 12) versus colchicine (n = 14). The minimum dose of prednisone used was 60 mg/d for 1 mo, tapered to 40 mg/d over the second month, tapered to 40 mg every other day during the third month, with subsequent doses adjusted as clinically indicated. The dose of colchicine was 0.6-1.2 mg/d, as tolerated. The presence of a rim of subpleural honeycomb change was present in all of the 25 subjects who had HRCT. Subjects treated with high-dose prednisone alone experienced a higher incidence of serious side effects and also exhibited a trend (not statistically significant, p = 0.391) to more rapid decline of pulmonary function and shortened survival than did those treated with colchicine alone. In most subjects with typical clinical and HRCT features of idiopathic UIP, neither prednisone nor colchicine resulted in objective improvement, and the disease continued to progress in the majority. Colchicine appears to be a safer alternative to a trial of high-dose prednisone but may be no different than no therapy.

Advanced multiple beam equalization radiography: receiver operating characteristic comparison with screen-film chest radiography

OBJECTIVE

To test the hypothesis that the advanced multiple beam equalization radiography (AMBER) imaging system is superior to conventional chest radiography in the demonstration of diffuse infiltrative lung disease, emphysema, pulmonary nodules, calcification within nodules, and mediastinal or hilar masses and lymphadenopathy.

MATERIAL AND METHODS

The study involved 115 patients, each of whom underwent chest computed tomography (CT), AMBER, posteroanterior chest radiography, and conventional posteroanterior stereoscopic chest radiography (two films). All radiographs were obtained with the InSight Thoracic Imaging System. Four chest radiologists independently analyzed the 115 AMBER studies, 115 unpaired single conventional radiographs (a single film from a stereoscopic pair), and 115 stereoscopic conventional radiographs (2 films) for the presence of diffuse infiltrative lung disease, emphysema, pulmonary nodules, calcification within nodules, and mediastinal or hilar masses and lymphadenopathy. For each abnormality detected, the radiologists described their level of confidence based on a scale of 1 to 5. The 115 CT examinations were interpreted by consensus among 3 of the chest radiologists. The CT results were considered the standard. Receiver operating characteristic (ROC) techniques were used for statistical analysis.

RESULTS

No statistically significant differences were found with ROC techniques between the AMBER system and single or stereoscopic conventional screen-film radiography for the abnormalities studied.

CONCLUSION

We noted no clinically significant difference between AMBER and either single or stereoscopic conventional screen-film radiography in this prospective study of 115 patients in which CT (performed within 1 week of both radiographic examinations) was the standard.

Accuracy of high-resolution CT in diagnosing lung diseases

OBJECTIVE

The purpose of our study was to determine if high-resolution CT facilitates the diagnoses of three diseases that cause cystic air spaces in the lungs: pulmonary eosinophilic granuloma, pulmonary lymphangiomyomatosis, and emphysema.

MATERIALS AND METHODS

Retrospective review of high-resolution CT findings in patients with pathologically proven pulmonary eosinophilic granuloma (n = 10), pulmonary lymphangiomyomatosis (n = 9), and emphysema (n = 10) and five control patients without cystic air spaces was conducted by two thoracic radiologists unaware of the pathologic diagnosis. After reviewing the scans, the radiologists made a diagnosis and indicated their level of confidence in the diagnosis on a three-point scale.

RESULTS

High-resolution CT allowed the two radiologists to be confident of the diagnosis of pulmonary eosinophilic granuloma in 84% of CT scans, lymphangiomyomatosis in 79%, and emphysema in 95%. When confident, the observers were correct in 100% of the cases. Agreement between observers was good for confident diagnoses based on high-resolution CT scans of pulmonary eosinophilic granuloma (kappa = .77), lymphangiomyomatosis (kappa = .88), and emphysema (kappa = 1). Distribution of cystic changes differed on high-resolution CT scans for lymphangiomyomatosis and pulmonary eosinophilic granuloma. No consistent distribution pattern was observed for emphysema. Lack of a perceptible cyst wall was unique to cases of emphysema. All patients with lymphangiomyomatosis lacked nodules in the intervening lung parenchyma, whereas most patients with pulmonary eosinophilic granuloma had parenchymal nodules.

CONCLUSION

High-resolution CT can help radiologists reliably diagnose pulmonary eosinophilic granuloma, lymphangiomyomatosis, and emphysema.

Technical aspects of twin screen-film chest radiography: cost effective lung and mediastinal imaging

OBJECTIVE

To determine the sensitometry and 'cross-talk' of a twin screen-film cassette and to assess its clinical potential.

MATERIALS AND METHODS

The twin cassette utilises two sets of screens, divided by filter material, to provide an optimised image of the mediastinum and the lungs. The exposure difference for the two images was measured sensitometrically. The contribution to film density of visible light and K-characteristic radiation, from adjacent screens in the absence of a dividing filter, was investigated.

RESULT

Clinical experience indicated that an exposure difference of 3.4 between the front and back screens, was optimal. Visible light and K-characteristic radiation from the front screens, contributed up to 20 and 24% respectively, of the back film exposure and screen absorbed energy respectively. This was reduced to 0 and 6% with the use of the filter.

CONCLUSIONS

The twin screen-film cassette provides extended latitude to enable optimal visualisation of the lung and mediastinal regions. Adjacent screen 'cross-talk' has been overcome to allow standard and portable chest applications.

Clinical evaluation of twin screen-film chest radiography: cost effective lung and mediastinal imaging

OBJECTIVE

A new twin screen-film cassette system optimised for conventional chest radiography was evaluated by four thoracic radiologists.

MATERIALS AND METHODS

The twin screen-film cassette system produces two film images, the front film optimised for the mediastinal region of the chest, the rear for the lung region. Image degradation on either screen-film system due to internal photon scatter has been virtually eliminated due to the use of a dividing filter. Fifty patients were included in a trial that resulted in a set of chest images for each patient, taken on the same inspiration, by both the twin screen-film cassette and the conventional system. The resultant fifty sets of images were evaluated by four chest radiologists who scored 12 radiographic features of the chest and patient pathologies present, using a paired difference technique.

RESULTS

The image quality of the twin screen-film cassette system was judged to be significantly superior to the conventional screen-film system in nine of the 12 radiographic features scored (P < 0.003). In the three other regions and for the patient pathologies, no significant conclusions were drawn.

CONCLUSION

The new twin screen-film system showed improved visualisation of radiographic features, particularly in the mediastinal and retrocardiac lung regions. This new system shows promise in both standard and portable clinical applications.

Late-onset noninfectious pulmonary complications after allogeneic bone marrow transplantation

We examined the incidence and clinical outcome of late-onset noninfectious pulmonary complications (LONIPC) in a series of 234 patients who underwent allogeneic bone marrow transplantation at our institution between April 1982 and October 1996. The 179 patients who survived 3 months or more were evaluated. Clinical, radiologic, pulmonary function, and pathologic tests were reviewed to identify 18 patients (10%) who fulfilled the diagnostic criteria of LONIPC. Accordingly, the pulmonary processes included bronchiolitis obliterans (BO, five patients), bronchiolitis obliterans with organizing pneumonia (BOOP, three patients), diffuse alveolar damage (DAD, one patient), lymphocytic interstitial pneumonia (LIP, one patient), and nonclassifiable interstitial pneumonia (NCIP, eight patients). Various methods of enhanced immunosuppressive therapy resulted in marked durable remission in nine patients (50%) (3/3 with BOOP, 3/8 with NCIP, 1/1 with DAD, 1/1 with LIP, 1/5 with BO). The presence of chronic graft-versus-host disease (cGVHD) and prophylaxis for GVHD with cyclosporine and prednisone were the only variables significantly associated with the development of LONIPC (P = 0.0001 and 0.008, respectively). Regardless of histology, a reduction in the forced expiratory volume to < 45% of the predicted range was associated with poor response to treatment. These findings suggest a strong association between cGVHD and LONIPC and that the risk of LONIPC development may be influenced by the particular method of GVHD prophylaxis. Most patients with BOOP or mild airflow limitation at diagnosis achieved durable remissions.

Mosaic attenuation pattern on thin-section CT scans of the lung: differentiation among infiltrative lung, airway, and vascular diseases as a cause

PURPOSE

To determine whether infiltrative lung, airway, or vascular disease can be differentiated as the cause of mosaic attenuation on thin-section computed tomographic (CT) scans of the lung.

MATERIALS AND METHODS

Thin-section CT scans were reviewed in 70 patients examined at three institutions. A mosaic attenuation pattern and pathologic or clinical proof of a specific type of disease were demonstrated. Causes of the mosaic pattern included infiltrative lung disease (n = 37), airway disease (n = 22), and vascular disease (n = 11). Thin-section CT findings were assessed independently by two observers blinded to clinical findings.

RESULTS

The type of disease was identified correctly at CT in 58 (83%) of 70 patients by observer 1 and 57 (81%) of 70 patients by observer 2. Infiltrative lung disease was diagnosed correctly by both observers in 34 (92%) of 37 cases. Observer 1 identified 21 (95%) of 22 cases of airway disease and three (27%) of 11 cases of vascular disease. Observer 2 identified 19 (86%) of 22 cases of airway disease and four (36%) of 11 cases of vascular disease.

CONCLUSION

Infiltrative lung disease and airway disease may be differentiated reliably as the cause of mosaic attenuation on lung CT scans, whereas vascular disease is often misinterpreted as infiltrative lung disease or airway disease.

Diffuse lung disease: diagnostic accuracy of CT in patients undergoing surgical biopsy of the lung

PURPOSE

To determine if there is a subset of patients undergoing surgical biopsy for diffuse lung disease in whom accurate diagnosis can be made with computed tomography (CT) only.

MATERIALS AND METHODS

Two chest radiologists retrospectively reviewed the CT scans of 85 patients in whom surgical biopsy for diffuse lung disease was performed. Thin-section CT images were available in 58 (68%) of the 85 cases. By consensus, the radiologists listed the three most likely diagnoses in order of probability and rated their level of confidence in the first choice.

RESULTS

Each of 85 patients with diffuse lung disease had one of 16 diseases. In 79 (93%) cases, the correct diagnosis was one of the three choices. In 54 (64%) cases, the correct diagnosis was the radiologists' first choice. A high level of confidence in the first choice was reached in 20 (24%) cases; all 20 cases were forms of chronic lung disease. In 18 (90%) of these 20 cases, the first choice was correct.

CONCLUSION

In a subset of patients with diffuse lung disease who undergo surgical biopsy, accurate diagnosis can be made with CT findings only.

Mosaic pattern of lung attenuation on CT scans: frequency among patients with pulmonary artery hypertension of different causes

OBJECTIVE

The purpose of this study was to determine the frequency with which a mosaic pattern of lung attenuation is seen on chest CT scans in patients with various causes of pulmonary artery hypertension (PAH).

MATERIALS AND METHODS

Chest CT scans of 64 patients with known PAH were reviewed to assess the patterns of lung attenuation. Patterns of lung attenuation were divided into three categories: class I, homogeneous lung parenchymal attenuation; class II, slightly heterogeneous lung attenuation that does not conform to the anatomic boundaries of the secondary pulmonary lobule; and class III (mosaic pattern), heterogeneous lung attenuation in geographic regions with well-defined borders corresponding to the anatomic units of single or multiple secondary pulmonary lobules. The patients medical histories were reviewed to determine the primary cause of PAH for each patient.

RESULTS

Peak pulmonary artery pressure of the patients in our study averaged 74 mm Hg (range, 36-194 mm Hg). Twenty-one patients had PAH due to lung disease: 17 patients, due to cardiac disease; and 23 patients, due to vascular disease. Three other patients had PAH due to miscellaneous causes. Of the 23 patients with PAH due to vascular disease, 17 patients (74%) had a mosaic pattern of lung attenuation. Of the 21 patients with PAH due to lung disease, one patient (5%) had a mosaic pattern of lung attenuation. Among the 17 patients with PAH due to cardiac disease, two patients (12%) had a mosaic pattern of lung attenuation. A mosaic pattern of lung attenuation was seen significantly more often in patients with PAH due to vascular disease than in patients with PAH due to cardiac or lung disease.

CONCLUSION

A mosaic pattern of lung attenuation can be seen on CT scans in patients with PAH due to vascular disease, cardiac disease, or lung disease. However, the mosaic pattern is seen significantly more often in patients with PAH due to vascular disease than in patients with PAH due to cardiac or lung disease.

Organizing pneumonia. Features and prognosis of cryptogenic, secondary, and focal variants

BACKGROUND

Organizing pneumonia (OP) is a non-specific response to many types of lung injury. Clinicians frequently encounter pathology reports of OP in patients with no underlying condition (cryptogenic OP, also known as BOOP or bronchiolitis obliterans OP) or in association with drugs or nonpulmonary disease. The goals of this study are to describe the clinical course and outcomes in patients with 3 clinical variants of OP.

METHODS

A retrospective study of patients with OP seen at the Mayo Clinic, Rochester, Minn, from January 1, 1984, through June 30, 1994, was conducted. Initial features were obtained from medical records. Chest radiographs and pathology specimens were reviewed for this study. Resolution, relapse, and survival were obtained from medical records and a follow-up patient questionnaire.

RESULTS

Seventy-four patients had pathologically confirmed OP. Organizing pneumonia was classified into 3 clinical groups: symptomatic cryptogenic OP; symptomatic OP related to underlying hematologic malignant neoplasm, collagen vascular disease, or drugs (secondary OP); and asymptomatic OP presenting as a focal nodule (focal OP). Thirty-seven patients (50%) had cryptogenic OP and 27 patients (36%) had secondary OP. No difference was found between cryptogenic and secondary OP in type or severity of symptoms, signs, laboratory and pulmonary function tests, or radiologic or pathologic findings. Corticosteroids were given at a similar initial dose (prednisone, about 50 mg/d). Resolution of symptoms was more frequent in patients with cryptogenic OP than those with secondary OP. Relapse was infrequent in both of these groups. Five-year survival was higher in patients with cryptogenic OP (73%) than in secondary OP (44%), and respiratory-related deaths were more frequent in patients with secondary OP. Organizing pneumonia was an asymptomatic focal rounded opacity in 10 patients (14%), most often detected on chest radiograph and diagnosed on lung biopsy done for suspicion of lung cancer. Patients with focal OP required no treatment and had no relapse or respiratory-related deaths.

CONCLUSIONS

Clinical classification of OP is useful to predict clinical course and outcome. Cryptogenic OP most often was a symptomatic bilateral lung process that had an overall favorable prognosis with prolonged corticosteroid therapy. Patients with secondary OP had a high mortality rate when the disease was associated with predisposing conditions or drugs. Patients with asymptomatic focal OP had an excellent prognosis.

The probability of malignancy in solitary pulmonary nodules. Application to small radiologically indeterminate nodules

BACKGROUND

A clinical prediction model to identify malignant nodules based on clinical data and radiological characteristics of lung nodules was derived using logistic regression from a random sample of patients (n = 419) and tested on data from a separate group of patients (n = 210).

OBJECTIVE

To use multivariate logistic regression to estimate the probability of malignancy in radiologically indeterminate solitary pulmonary nodules (SPNs) in a clinically relevant subset of patients with SPNs that measured between 4 and 30 mm in diameter.

PATIENTS AND METHODS

A retrospective cohort study at a multispecialty group practice included 629 patients (320 men, 309 women) with newly discovered (between January 1, 1984, and May 1, 1986) 4- to 30-mm radiologically indeterminate SPNs on chest radiography. Patients with a diagnosis of cancer within 5 years prior to the discovery of the nodule were excluded. Clinical data included age, sex, cigarette-smoking status, and history of extrathoracic malignant neoplasm, asbestos exposure, and chronic interstitial or obstructive lung disease; chest radiological data included the diameter, location, edge characteristics (eg, lobulation, spiculation, and shagginess), and other characteristics (eg, cavitation) of the SPNs. Predictors were identified in a random sample of two thirds of the patients and tested in the remaining one third.

RESULTS

Sixty-five percent of the nodules were benign, 23% were malignant, and 12% were indeterminate. Three clinical characteristics (age, cigarette-smoking status, and history of cancer [diagnosis, > or = 5 years ago]) and 3 radiological characteristics (diameter, spiculation, and upper lobe location of the SPNs) were independent predictors of malignancy. The area (+/-SE) under the evaluated receiver operating characteristic curve was 0.8328 +/- 0.0226.

CONCLUSION

Three clinical and 3 radiographic characteristics predicted the malignancy in radiologically indeterminate SPNs.

Colchicine versus prednisone as treatment of usual interstitial pneumonia

OBJECTIVE

To assess the results with colchicine and prednisone as initial single-drug therapy in patients with usual interstitial pneumonia (UIP).

MATERIAL AND METHODS

We reviewed the serial pulmonary function test results in 22 patients with typical clinical and high-resolution computed tomographic features of UIP who were treated with colchicine as initial single-agent therapy and compared them with a group of 22 historical patients with UIP of similar severity diagnosed by open-lung biopsy who were given prednisone as initial single-drug therapy.

RESULTS

No significant difference was detected in the rate of decline of pulmonary function or in the time to "failure" between the two study groups. A trend was suggested for more rapid decline of pulmonary function in the prednisone-treated than in the colchicine-treated group. The design of this study does not allow distinction between a possible beneficial effect of colchicine and a possible adverse effect related to weaning from high-dose prednisone. Colchicine was well tolerated; few side effects other than mild diarrhea were noted in those patients able to take the drug long enough to return for pulmonary function testing at 3 months. In comparison, the side effects of prednisone were more serious and were not always reversible with cessation of therapy.

CONCLUSION

This study lends further support to the assumption that colchicine may be a satisfactory and less hazardous substitute for prednisone in the treatment of patients with UIP.

Cigarette smoking: CT and pathologic findings of associated pulmonary diseases

The health risks associated with cigarette smoking are well known. Cigarette smoking is the most important causative factor in the development of bronchogenic carcinoma. Pulmonary diseases such as chronic bronchitis, centrilobular and panacinar emphysema, respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and pulmonary Langerhans cell histiocytosis are also related to cigarette smoking. In adenocarcinoma and squamous cell carcinoma, the most common manifestation at computed tomography (CT) is a solitary pulmonary nodule; in small cell carcinoma, hilar and mediastinal adenopathy secondary to metastases; and in large cell carcinoma, a mass with central necrosis or cavitation in the lung periphery. For chronic bronchitis, the most common CT finding is bronchial wall thickening, but this finding is nonspecific. Emphysema, both centrilobular and panacinar associated with alpha-1-antitrypsin deficiency, usually manifests as areas of decreased attenuation and may involve bullous changes. However, centrilobular emphysema more commonly involves the upper lungs, whereas panacinar emphysema more commonly involves the lower lungs. Most patients with RB-ILD have normal high-resolution CT scans; however, abnormalities may be present, the most common of which are areas of ground-glass attenuation. CT appearance of pulmonary Langerhans cell histiocytosis varies depending on the disease stage: In the early stage, typical CT findings include multiple nodules, usually accompanied by cystic spaces with thin, well-defined walls. As the disease progresses, the cystic spaces become more numerous and the number of nodules decreases.

Thoracic cross-sectional imaging of amyloidosis

OBJECTIVE

Our objective was to determine the thoracic manifestations on cross-sectional imaging of patients with tissue-proven amyloidosis.

MATERIALS AND METHODS

We reviewed the records of 300 patients with the diagnosis of amyloidosis on whom cross-sectional imaging was done at our institution between 1985 and 1995. After exclusions, 19 patients with tissue-proven amyloidosis and cervicothoracic cross-sectional imaging were included. Seven patients had localized amyloidosis and 12 patients had systemic amyloidosis. Eighteen patients underwent CT scans and the remaining patient, MR imaging.

RESULTS

Two patients with systemic amyloidosis had widespread noncalcified adenopathy. A third patient had an infiltrative soft-tissue process in the mediastinum and axillae containing thick linear and focal calcifications. Five patients with localized amyloidosis had pulmonary nodules: Three patients had solitary nodules, one patient had two nodules, and one patient had 10 nodules. Nodules ranged in size from 8 mm to 3 cm. Eight patients with systemic amyloidosis had diffuse lung disease. One patient with systemic amyloidosis had recurrent right pleural effusions. Two patients with localized amyloidosis had laryngotracheobronchial amyloidosis. One of the two patients had focal thickening of the right aryepiglottic fold. The other patient had diffuse concentric soft-tissue thickening within the trachea.

CONCLUSIONS

Localized amyloidosis can occur in patients as pulmonary nodules or as laryngotracheobronchia involvement. Nodules are typically solitary (60%) with a smooth or lobular contour and are frequently in a subpleural or peripheral location. Calcification is not common (20%). Systemic amyloidosis can occur in patients as a combination of adenopathy (75%), multiple pulmonary nodules (50%), and diffuse irregular lines or interlobular septal thickening (50%).

Pulmonary artery sarcoma. Clinical features

STUDY OBJECTIVES

To define characteristic clinical and radiographic presentations of patients found to have primary sarcoma of the pulmonary artery and differentiate this entity from acute and chronic pulmonary thromboembolism. To review pathologic characteristics of pulmonary artery sarcoma.

DESIGN

A retrospective review of medical records at a large medical center and a review of the literature.

SETTING

Tertiary care medical center.

PATIENTS

Patients found to have pulmonary artery sarcoma based on surgical or autopsy findings.

INTERVENTIONS

Review of medical records.

MEASUREMENTS AND RESULTS

Presenting symptoms of patients with pulmonary artery sarcoma are similar to those of patients with other pulmonary vascular disease, including progressive dyspnea, cough, hemoptysis, and chest pain. Symptoms not commonly associated with pulmonary vascular disease consist of progressive weight loss, anemia, and fever, which are symptoms commonly associated with malignancy. The diagnosis is often not suspected prior to surgery, which is often undertaken with an alternative diagnosis such as bronchogenic carcinoma or chronic pulmonary thromboembolism. Prolonged survival is rare; most patients survive only a few months. Survival longer than 3.5 years was not observed. Recent experience with MRI of the thorax and transesophageal echocardiography suggests that these diagnostic entities may be rewarding in separating the abnormalities seen on chest radiographs and angiography from thrombus in the pulmonary artery, mediastinal adenopathy, or primary bronchogenic carcinoma.

CONCLUSIONS

Although a rare entity, the key is to suspect the presence of pulmonary artery sarcoma in evaluation of patients with atypical presentations of pulmonary vascular disease especially if associated with symptoms such as weight loss, fever, or anemia.

Lung nodule enhancement at CT: prospective findings

PURPOSE

To determine if lung nodule enhancement measured with computed tomography (CT) is directly related to the likelihood of malignancy and to nodule vascularity.

MATERIALS AND METHODS

Radiologically indeterminate 7-30-mm pulmonary nodules were studied in 107 patients with malignant neoplasms (n = 52), granulomas (n = 51), and benign neoplasms (n = 4). Attenuation was recorded from serial thin-section CT scans before and after injection of contrast material. Twenty-four histologic specimens were graded after immunoperoxidase vascular staining with antibody to factor VIII-associated antigen.

RESULTS

Malignant neoplasms were enhanced (median, 46.5 HU; range, 11-110 HU) statistically significantly more than granulomas and benign neoplasms (median, 8 HU; range, -10 to 94 HU) (P < .001). With 20 HU as the threshold for a positive test result, the sensitivity was 98%, specificity was 73%, and accuracy was 85% (prevalence of malignancy, 49% ¿52 of 107 nodules]). The degree of enhancement was statistically significantly related to the amount of central vascular staining (P < .001).

CONCLUSION

Enhancement appears to be an indicator of malignancy and vascularity. These prospective findings corroborate previously reported results.

Pulmonary venoocclusive disease: CT findings in eight patients

OBJECTIVE

The objective of the study was to describe the CT findings of pulmonary venoocclusive disease.

MATERIALS AND METHODS

Eight patients with CT scans of the thorax and a diagnosis of pulmonary venoocclusive disease were identified from three institutions. The six males and two females had a mean age of 32 years old (range, 5-58 years old). All scans were evaluated with consensus reading by two chest radiologists. Lung parenchyma were assessed for the type and distribution of disease. Bronchi, pleura, hila, mediastina, and chest walls were evaluated for abnormalities. Pathologic specimens from five patients were reviewed and specifically correlated with the radiologic findings.

RESULTS

Seven of the eight patients had interlobular septal thickening. All eight patients had regions of ground-glass opacity. Four of the eight patients had a mosaic pattern of lung attenuation. No enlarged hilar or mediastinal nodes were revealed. Five patients had bilateral pleural effusions.

CONCLUSION

The most common CT findings in these eight patients with pulmonary venoocclusive disease were smooth interlobular septal thickening, diffuse multifocal regions of ground-glass opacity, pleural effusions, enlarged central pulmonary arteries, and pulmonary veins of normal caliber. Four patients had a mosaic pattern of lung attenuation on the CT scans. These findings are highly suggestive of pulmonary venoocclusive disease and may be helpful in difficult cases. Definitive diagnosis requires lung biopsy.