Asbestosis: high-resolution CT-pathologic correlation

High-resolution computed tomography (HRCT) was performed in seven inflated and fixed postmortem lungs from seven asbestos-exposed patients with pathologically proved asbestosis. The parenchymal abnormalities seen at in vitro HRCT included thickened intralobular lines (n = 7), thickened interlobular lines (n = 7), pleural-based opacities (n = 7), parenchymal fibrous bands (n = 5), subpleural curvilinear shadows (n = 4), ground-glass appearance (n = 4), traction bronchiectasis (n = 4), and honeycombing (n = 2). The thickened intralobular lines were shown histologically to be due to peribronchiolar fibrosis. Thickened interlobular lines were due mainly to interlobular fibrotic thickening in four lungs and edema in three. The peribronchiolar fibrosis was most severe in the subpleural lung regions, creating curvilinear line shadows and pleural-based areas of opacity. Some subpleural fibrosis extended proximally along the bronchovascular sheath to create bandlike lesions. Areas of ground-glass appearance on HRCT scans were shown to be the result of mild alveolar wall and interlobular septal thickening due to fibrosis or edema. Postmortem HRCT findings were similar to premortem HRCT findings and correlated well with the pathologic findings of asbestosis.     

The fibromatoses: CT-pathologic correlation

Although CT has been used in the evaluation of benign fibroblastic tumors (fibromatoses), data are lacking on radiologic-histopathologic correlation. In an attempt to explain the variable CT appearance of these lesions, a retrospective analysis was carried out of CT findings and histopathologic features in nine patients with fibromatoses. In three of four patients who had precontrast CT scans, the tumors were hyperdense relative to muscle, whereas in one patient the lesion was hypodense. The postenhancement appearance was variable. The pathologic specimens were analyzed and graded for collagen content, cellular content, tumor necrosis, and tumor vascularity. No consistent relationship could be established between the CT appearance of these lesions and their histologic appearance.     

Centrilobular emphysema: CT-pathologic correlation

Over a 5-year period, 25 patients who had undergone chest computed tomography (CT) died and were autopsied. Their lungs were fixed in the inflated state and were assessed for the presence and severity of centrilobular emphysema (CLE). Three radiologists independently evaluated the CT scans for nonperipheral low-attenuation areas, peripheral low-attenuation areas, pulmonary vascular pruning, pulmonary vascular distortion, and pulmonary density gradient. The CT criterion that best correlated with the presence and severity of CLE was the nonperipheral low-attenuation area. With this CT criterion, lung destruction was correctly identified in 13 of 15 cases. The absence of this criterion resulted in correct identification of eight of ten normal lungs. These preliminary data suggest that CLE can be reliably identified and quantified with current CT scanners.     

Fibrosing alveolitis in patients with neurofibromatosis.

Fibrosing alveolitis, or interstitial pulmonary fibrosis, is a common manifestation of neurofibromatosis, and was observed in 7 of 70 patients with the disease. Though neurofibromatosis is congenital, fibrosing alveolitis does not appear until adulthood, and occurs in 20% of patients with the disease who are over 30 years old. Characteristic radiographic findings include linear, interstitial density, and large upper lobe bullae; this combination limits the differential diagnosis. Pathological examination demonstrates alveolar wall thickening progressing to fibrosis and lung destruction. Pulmonary function tests can show obstructive or restrictive lung disease.     

Pulmonary metastatic nodules: CT-pathologic correlation.

To elucidate the characteristics of pulmonary metastatic nodules on high-resolution computed tomographic (HRCT) scans, a correlative computed tomographic (CT)-pathologic study was performed with five human lungs after autopsy. The relationship of metastatic nodules to pulmonary vessels was studied with HRCT scans, radiographs of the specimen, and stereomicroscopic study in 264 nodules 0.6-9.0 mm in diameter. On radiographs and stereomicroscopic images, 190 small nodules (less than 3 mm in diameter) were in contact with the pulmonary lobule on the central bronchovascular bundles (n = 33 [17.4%]), located between the central bronchovascular bundle and the perilobular structure (n = 127 [66.8%]), or attached to perilobular structures (n = 30 [15.8%]). On HRCT scans, 21 small nodules (11.1%) were located on the central bronchovascular bundle; 130 small nodules (68.4%), between the central bronchovascular bundle and the perilobular structure; and 39 small nodules (20.5%), on the perilobular structure. On radiographs and stereomicroscopic images, 43 of 74 large nodules (greater than 3 mm in diameter) (58%) compressed both bronchovascular bundles and perilobular structures. The central bronchovascular bundle was invaded in only 13 large nodules (18%).     

Malignant thymic epithelial tumors: CT-pathologic correlation

OBJECTIVE: The purpose of our study was to describe and compare the CT and pathologic findings of atypical thymoma and thymic carcinoma. MATERIALS AND METHODS: Twenty-seven consecutive patients (14 men, 13 women ranging in age from 22 to 77 years [mean age, 52 years]) with pathologically proven atypical thymoma (n = 9) and thymic carcinoma (n = 18) constituted the study population. The chest CT findings in each of the 27 patients were reviewed retrospectively in consensus by two chest radiologists. These findings were correlated with pathologic findings. RESULTS: The tumors were located in the anterior mediastinum, and most tumors had a lobulated margin (24/27, 89%). Atypical thymomas were significantly smaller (mean, 4.7 cm) than thymic carcinomas (mean, 7.2 cm) (p = 0.041) on CT. The findings of invasion of the great vessels, lymph node enlargement, extrathymic metastases, and phrenic nerve palsy were seen only in patients with thymic carcinoma. The frequencies of necrosis, intratumoral calcification, pleural effusion, pleural implants, pericardial effusion, and obliteration of the mediastinal fat plane were not significantly different between atypical thymomas and thymic carcinomas (p > 0.05). Various histologic subtypes were included in thymic carcinoma. The tumor necrosis and calcification seen on CT were confirmed at pathologic examination. CONCLUSION: When a large thymic tumor appears with invasion of the great vessels, lymph node enlargement, phrenic nerve palsy, or extrathymic metastases on CT, thymic carcinoma rather than atypical thymoma should be considered.     

Multicentric adenocarcinoma of the lung: CT-pathologic correlation

To evaluate the sensitivity of computed tomography (CT) in detecting multicentric primary bronchogenic adenocarcinoma manifesting as a pulmonary nodule, the authors reviewed CT scans and pathologic specimens of 158 consecutive patients who underwent resection of a pulmonary nodule. Two independent observers assessed the scans without knowledge of the pathologic findings. Lung specimens were fixed in inflation and sectioned transversely, analogous to the plane of the CT scans. In 88 patients the nodule represented adenocarcinoma. Multicentric adenocarcinoma was present in 19 of these patients (22%). The sensitivity of CT in correctly detecting the presence and location of two or more lesions was 0.63 and 0.68 for two observers, with a specificity of 0.86 for both. The CT appearance of multicentric disease varied from well-defined nodules to ill-defined hazy opacities simulating pneumonitis. The data indicate that (a) multicentric adenocarcinomas are more common than generally reported in the literature and (b) meticulous evaluation of CT images enables detection of multicentricity in a high percentage of cases.     

Fibrosing alveolitis: prognostic implication of ground-glass attenuation at high-resolution CT.

To evaluate the prognostic implication of ground-glass attenuation at high-resolution computed tomography (HRCT) in assessing response to treatment in fibrosing alveolitis, the authors correlated HRCT findings with the improvement in pulmonary function, as represented by the increase in percentage predicted values on pulmonary function tests after corticosteroid therapy. Nineteen patients underwent HRCT before treatment and pulmonary function testing before and after treatment. The HRCT scans were reviewed by two independent observers. Areas of ground-glass attenuation were quantified subjectively by using a 0%-100% scale with 10% increments. The extent of ground-glass attenuation at HRCT was significantly correlated with improvement in diffusing capacity for carbon monoxide (r = .67, P = .0019), forced vital capacity (r = .71, P = .0007), and forced expiratory volume in 1 second (r = .64, P = .0034) after steroid treatment. These results suggest that ground-glass attenuation at HRCT is a good predictor of response to treatment in fibrosing alveolitis.     

CT-pathologic correlation in small peripheral lung cancers

To evaluate the morphology of small peripheral lung cancers, we studied thin-section CT images of 18 small peripheral lung cancers (14 adenocarcinomas, two squamous-cell carcinomas, one large-cell carcinoma, and one carcinoid) in 17 patients. After surgical resection, specimens were sliced transversely, and the gross morphology and histology were correlated with the appearance of the lesion on preoperative thin-section CT images. CT images showed fine speculations in 78%, a notch in 83%, pleural retraction in 78%, and convergence of peripheral vessels in 83% of the 18 lung cancers. Furthermore, in cases of papillary adenocarcinoma, the lesions had heterogeneous densities (78%) and small cavitations (67%). CT showed a peripheral fluffy zone in most of the well- or moderately differentiated papillary adenocarcinomas. This correlated well with tumor cells lining the alveolar walls, observed in pathologic studies. Comparison of thin-section CT images with pathologic data suggests that the demonstration of the lung-tumor interface and the tumor's internal texture, while not specific for malignant lesions, can make the CT diagnosis of small peripheral lung cancers more accurate.     

Benign tumors of the tracheobronchial tree: CT-pathologic correlation

OBJECTIVE: The purpose of this essay is to illustrate the CT findings of variable benign tumors of the tracheobronchial tree and to correlate the CT and pathologic findings in 17 patients. CONCLUSION: The tracheal tumors were eccentric, well-defined, polypoid masses in all cases. The endobronchial tumors were masses confined within the bronchus in all cases, and atelectasis or pneumonia of the distal parenchyma was frequently associated. Of the six hamartomas, one was a fatty mass, and two were nodules with calcification. The others were soft-tissue-density nodules. The lipomas manifested as fat density on CT scans in both cases. The other benign tumors were low-attenuating, soft-tissue-density masses without characteristic findings on CT scans.     

Peripheral low-density area of hepatic tumors: CT-pathologic correlation

To aid in the distinction between colorectal cancer metastasis to the liver and hepatocellular carcinoma, findings on computed tomographic (CT) scans taken more than 5 minutes after contrast material administration ("late-enhanced CT scans") and pathologic findings were compared. Late-enhanced CT scans of metastatic adenocarcinoma showed a peripheral low-density area (PLDA) that corresponded to viable tumor and a central high-density area that represented fibrous connective tissue. This phenomenon was recognized in 15 of 20 (75%) patients with metastatic adenocarcinoma and in one of 50 (2%) patients with hepatocellular carcinoma. Late-enhanced CT scans may be useful in distinguishing between metastatic nonmucinous colorectal cancer and hepatocellular carcinoma.     

Radiolucencies and cavitation in bronchioloalveolar carcinoma: CT-pathologic correlation

Bronchioloalveolar carcinoma (BAC) is a polymorphic lung cancer the incidence of which is rising. The presence of intratumoral radiolucencies is an important feature of bronchioloalveolar carcinoma.The aim of this study was to present pictorially the spectrum of intratumoral radiolucencies visible in BAC. In 57 BACs studied with thin-slice CT, we identified six types of radiolucencies: (a) patent intratumoral bronchioles (air bronchiologram); (b) pseudocavitations; (c) cavitation; (d) serpentine radiolucencies; (e) internal alveologram; and (f) multiple cystic lesions. Received: 31 December 1997; Revision received: 23 March 1998; Accepted: 28 April 1998     

Primary papillary serous carcinoma of the peritoneum: CT-pathologic correlation

We present the CT findings of three cases of primary papillary serous carcinoma of the peritoneum. All patients presented with massive ascites. CT of the abdomen and pelvis showed omental caking in all patients. The parietal peritoneum of the pelvis showed diffuse enhancement with nodular thickening in all patients. No calcification was noted in the omental and parietal peritoneal masses, although psammoma bodies were present microscopically in one case. The ovaries were normal in size but showed a fine enhancing surface nodularity similar to the pelvic peritoneum. The CT findings of primary papillary serous carcinoma of the peritoneum are nonspecific, but this diagnosis should be considered when peritoneal carcinomatosis is seen on CT with normal-sized ovaries in the absence of other primary malignant neoplasms.     

Parietal pleura and extrapleural space in chronic tuberculous empyema: CT-pathologic correlation

PURPOSE: The purpose of this work was to describe CT findings of the parietal pleura and extrapleural space in patients with chronic tuberculous empyema and to compare them with histopathologic findings following decortication. METHOD: Chest CT scans obtained from 13 patients with chronic tuberculous empyema who underwent decortication were retrospectively reviewed. All patients were men from 18 to 67 years old (mean 42 years old). CT findings of the parietal pleura and extrapleural space were correlated with histopathologic findings in all patients. RESULTS: Histopathologically, the enhanced parietal pleural peel on CT was fibrous collagenous tissue, and a low attenuated layer with 2 mm thickness within the parietal pleural peel (n = 2) was either a layer of histiocytes or caseation necrosis. The extrapleural space seen as an intermediate attenuation in six patients on CT was the proliferation of vessels, inflammatory cells, and granulomas in loose collagen background. The linear soft tissue attenuation interrupting the extrapleural fat (n = 5) on CT was a collagenous fibrous layer with proliferation of vessels and inflammatory cells. CONCLUSION: A layer of low attenuation in the parietal pleural peel may be due to different episodes of infection. The extrapleural space with intermediate attenuation may indicate ongoing inflammation. Linear soft tissue attenuation interrupting the extrapleural fat represents a fibrous layer rather than the subcostalis muscle.     

Mucinous cystadenocarcinoma of the lung: CT-pathologic correlation in three cases.

Mucinous cystadenocarcinoma (MCA) is a rare tumor that is considered to be a cystic variant of mucin-producing lung adenocarcinoma. MCA expands grossly by storing mucus and contains few neoplastic cells. We present the CT images of three patients with MCA and correlate them with pathologic specimens. The CT findings of MCA include a uniform low-attenuation, focal thickening of the cystic wall and enhancing septa.