Basement membrane patterns, gelatinase A and tissue inhibitor of metalloproteinase-2 expressions, and stromal fibrosis during the development of peripheral lung adenocarcinoma

To clarify the process and mechanisms of the development and progression of peripheral lung adenocarcinoma, we investigated the relationships among the patterns of basement membrane (BM), stromal fibrosis, and the expressions of gelatinase A and tissue inhibitor of metalloproteinases-2 (TIMP-2) in 33 lesions of atypical alveolar cell hyperplasia (AAH) and 48 lesions of lung adenocarcinoma, including 24 lesions of bronchioloalveolar carcinoma (BAC). We found that the architecture of alveolar BM was intact in all 33 AAH lesions and 11 nonsclerosing BAC lesions that formed no central scar, suggesting that these lesions are early-stage intraepithelial neoplasia. The preexistent BM of the lung was disrupted, and the BM components around the neoplastic glands were disrupted or absent in the area of the central scar of some sclerosing BAC lesions with collapse fibrosis alone (2 of 4) and in those of all of the adenocarcinoma lesions associated with desmoplastic stromal fibrosis (nine sclerosing BAC and 24 non-BAC tumors). These results suggested that, in lung adenocarcinomas, destruction of the BM was correlated with the formation of a central scar, particularly with desmoplasia. It is likely that adenocarcinomas with a central scar are advanced and invasive cancers potentially having metastatic activity. The expression of gelatinase A and TIMP-2 was associated with central scar formation as well as with destruction of the BM components. Both the neoplastic and stromal cells expressed gelatinase A and TIMP-2 and probably play a role in tumor cell invasion.     

Pulmonary elastic fiber degradation in paraquat toxicity. An electron microscopic immunohistochemical study

To study the morphologic alterations of pulmonary elastic fibers in cynomolgus monkeys with paraquat toxicity, peroxidase- and ferritin-labeled antielastin antibodies were used for the light and electron microscopic localization of elastin. One week after paraquat, alveolitis, tissue damage and alveolar dilatation were present; elastic fibers were frayed and more diffusely and intensely stained than those of control animals. In the latter, staining was localized in peripheral regions of the amorphous components and, to a lesser extent, in some microfibrils of elastic fibers. At 3 to 4 weeks, diffuse staining was evident in damaged interstitial elastic fibers and in newly formed elastic fibers in areas of intraalveolar fibrosis. At 8 weeks, the interstitium contained many elastic fibers which showed staining only in peripheral regions of the amorphous components. These observations suggest that: 1) preembedding immunohistochemical staining for elastin is localized in peripheral regions of normal elastic fibers because the antielastin antibody can penetrate into mature and undamaged amorphous components only to a very limited extent; 2) in early stages of paraquat toxicity this staining is more diffuse and intense because elastase from inflammatory cells partially degrades the elastic fibers and permits greater penetration of the antibody into the amorphous materials; 3) in later stages the staining pattern returns to normal as inflammation subsides and elastic fibers are repaired; however, newly formed elastic fibers in areas of intraalveolar fibrosis stain diffusely, reflecting increased penetration of the antibody because of immaturity and incomplete cross-linking, and 4) degeneration of elastic fibers of alveolar walls in paraquat lung may lead to alveolar dilatation, which is associated with irregular fibrosis and constitutes one of the processes of pulmonary structural remodeling in paraquat lung.(ABSTRACT TRUNCATED AT 250 WORDS)     

Elastic fibers in myocardial scars in rats: development teraction with other components

This work was designed to determine the course of development of elastic fibers in myocardial scars in rats and their relationship to other components of such structures. Light and electron microscopic observations were made on tissues from 24 rats, killed at sequent stages from 4 to 24 days postinjury. By both techniques, elastic fibers, shown to be forming by 4 days, had increased in size and number with maturation of the scar. At later stages they became interdigitated with the stumps of viable myocytes. We also saw that these fibers often had formed close contacts with the cell surfaces of myofibroblasts and nonvascular smooth muscle cells; a process found in some other situations but not previously in myocardial scars. This information is relevant, in particular, to the dynamics of myocardial scars and thus to the maintenance of function in the injured heart, but also to elastic fiber behavior in general. The integral role of elastic fibers in cell-matrix interactions as well as their biomechanical function is emphasized.     

Role of elastic fiber degradation in emphysema-like lesions of pulmonary lymphangiomyomatosis

To study the pulmonary structural remodeling in pulmonary lymphangiomyomatosis, electron microscopy and light and electron microscopic immunohistochemical observations for elastin and alpha 1-antitrypsin were performed on five open lung biopsy samples. Lung specimens showed emphysema-like changes in areas of abnormally accumulated smooth muscle cells. In the alveolar walls having accumulated smooth muscle cells, elastic fibers were decreased in number, disrupted, granular, and occasionally accumulated. Ultrastructurally, elastic fibers in areas of smooth muscle cell accumulation showed poorly outlined amorphous components and a few microfibrils, and occasionally showed electron-dense granular deposits in and around the amorphous components. Spiraling collagen fibrils were frequently found associated with these abnormal elastic fibers. Immunohistochemistry for elastin showed even staining of amorphous components of elastic fibers in the areas of smooth muscle cell accumulation. alpha 1-Antitrypsin was also detected evenly in amorphous components of elastic fibers in the areas of smooth muscle cell accumulation. It is proposed that the emphysema-like lesions of lymphangiomyomatosis are mediated by the degradation of elastic fibers, and these degraded elastic fibers are related to an imbalance of the elastase/alpha 1-antitrypsin system similar to the probable pathogenesis of emphysema.     

Papillary adenoma of the lung with a peculiar raw macroscopic feature

We report a case of papillary adenoma of the lung with a peculiar raw macroscopic feature at intraoperative consultation. A 52-year-old man was admitted to our hospital for the evaluation of a solitary peripheral nodule in the left lower lobe which was detected with chest CT. When we took staples off from the stump of the partially resected lung in order to make a frozen section diagnosis, granular fragments leaked out from the stump. On the cut surface, the dark reddish and granular tumor grew expansively; however, hemorrhage and necrosis were absent. Histologically, granular fragments were mainly composed of papillary structures, which consisted of a single layer of cuboidal to low columnar cells with round to oval nuclei lining the surface of the fibrovascular cores. Characteristically, papillary structures lacked elastic fibers in the stroma and were packed within an elastic fiber framework derived from pre-existing alveolar structures. We considered that high intratumoral pressure might have made the granular fragments leak out of the stump as soon as we removed staples and that peculiar macroscopic findings before fixation may be a diagnostic clue for papillary adenoma.     

Elastic Fibers in Myocardial Scars in Rats: Development Teraction with Other Components

This work was designed to determine the course of development of elastic fibers in myocardial scars in rats and their relationship to other components of such structures. Light and electron microscopic observations were made on tissues from 24 rats, killed at sequent stages from 4 to 24 days postinjury. By both techniques, elastic fibers, shown to be forming by 4 days, had increased in size and number with maturation of the scar. At later stages they became interdigitated with the stumps of viable myocytes. We also saw that these fibers often had formed close contacts with the cell surfaces of myofibroblasts and nonvascular smooth muscle cells; a process found in some other situations but not previously in myocardial scars. This information is relevant, in particular, to the dynamics of myocardial scars and thus to the maintenance of function in the injured heart, but also to elastic fiber behavior in general. The integral role of elastic fibers in cell-matrix interactions as well as their biomechanical function is emphasized.     

Myofibroblast activity of radial scars

Radial scars from 38 cases, comprising 12 associated with cancer and 26 with benign lesions, have been examined by electron microscopy. One-third of the lesions, regarded as being at an early stage of development, showed abundant spindle cells, which displayed the ultrastructural characteristics of myofibroblasts. These included many profiles of endoplasmic reticulum, prominent myofilaments and a close association with collagen and elastic fibres. The remaining ‘mature’ radial scars showed relatively few myofibroblasts, sparsely distributed in the stroma. The stromal cells associated with the ‘early’ lesions were seen in close proximity to degenerating parenchymal struclures, which frequently showed loss of basal lamina. Obliteration of the central parenchymal component appeared to be a prominent feature of radial scar formation. The ultrastructural appearances are consistent with a progressive development of the lesion, associated with sporadic myofibroblast activity.     

The extracellular matrix of peripheral lung cancer in the scar and of pneumosclerosis of different origins (the immunohistochemistry and electron microscopy of the collagens)]

Collagen types and ultrastructural features of the stroma and scar extracellular matrix in the peripheral lung carcinoma, post-tuberculosis and post-pneumonia pneumosclerosis foci, fibrosing alveolitis interstitium were studied on the material of operational and transbronchial lung biopsies. It is established that by the collagen composition the scars in the peripheral carcinoma are identical to the pneumosclerosis foci and are distinguished from the carcinoma stroma by a higher concentration of type IV and V collagens (p less than 0.05). Accumulation of type III collagen in the lung carcinoma stroma reflects anaplasia of the tumour as the domination of type III collagen is characteristic of the embryonal tissue. The decrease of collagen type IV in the cancer stroma correlates with an increase of its malignancy. Pneumosclerosis in the fibrosing alveolitis is distinct from the focal forms of pneumosclerosis by a higher content of collagen I and a lower content of collagen V this being probably due to the character of sclerosis morphogenesis in this disease.     

Diabetic macro- and microangiopathy of the lungs

Results of histologic, immunohistochemical and ultrastructural examination of pulmonary vessels of 85 necropsy cases (65 patients had diabetes and 20 were controls with atherosclerosis). In the lung vessels in diabetes the changes in the arteries of the elastomuscular and muscular types were frequently found (73.8 and 81.5%, respectively) which were regarded as manifestations of diabetic macroangiopathy, as well as those of arterioles, capillaries (81.5 and 55.4%, respectively) which are the expression of diabetic macroangiopathy. Macroangiopathy is represented by thickening of the endothelial basal membrane, destruction of the internal elastic lamina, its mucoid edema. An extreme manifestation is lipogranulomatosis of the arteries of muscle type. These changes are frequently associated with arterial thrombosis. Diabetic microangiopathy is characterized by plasmorrhagy and hyalinosis of the wall (lipohyaline) with the development of the nodular arteriolo-hyalinosis, the thickening of the endothelial basal membrane and frequent necrosis of capillary pericytes. A specific feature of the diabetic angiopathy is lipidosis of all cells in the lung artery system and its extracellular structures combined with lipidosis of type II pneumocytes producing surfactant and phagocyting alveolar macrophages and polinuclear leukocytes.     

Peripheral cancer of the lung and tuberculosis

Morphological analysis of 90 observations with a clinical diagnosis of a small peripheral lung carcinoma is performed. The examination of an operation material confirmed diagnosis in 71 cases. Tuberculomas are found in 19 cases. The peripheral lung carcinoma was found to develop in 91.5% (65 cases) against the background of preexisting scars which in 73.8% (48 cases) had a post-tuberculosis and 26.2% (17) post-pneumonia origin. Scars were most frequently related to the healed forms of a focal secondary tuberculosis (30 cases) and sclerotic changes around tuberculomas (8). Post-tuberculosis scars provoking sclerosis and deformation of vessels, bronchi, bronchioles and alveoles with the development of an epithelial dysplasia, are one of the risk factors in the development of a peripheral lung carcinoma. The degradation and fibrinoid changes of a scar tissue infiltrated by a tumour and followed by destruction of scars are observed in peripheral lung carcinomas with a diameter more than 3 cm.     

Microangiitis in lupus-induced pulmonary hemorrhage

The authors describe four patients with systemic lupus erythematosus (SLE) and massive pulmonary hemorrhage in whom open-lung biopsies showed a distinctive small-vessel vasculitis. This lesion is characterized by acute inflammation and necrosis involving capillaries, arterioles, and small muscular arteries and is termed microangiitis to reflect the small size of the affected vessels. The involvement of capillaries is manifested by an infiltrate of necrotic neutrophils within alveolar septa often associated with destruction of the alveolar wall. This capillaritis was present in all cases, while involvement of arterioles and small arteries was seen in three. Immunofluorescence and electron microscopy demonstrated immune complexes in only two. The finding of acute microangiitis in a lung biopsy from a patient with pulmonary hemorrhage should suggest the diagnosis of SLE, and it may be a more reliable diagnostic feature than the demonstration of immune complexes.     

Pulmonary tuberculosis with unusual cystic change in an immunocompromised host

We present a rare case of upper zone cystic change of the lung with disseminated tuberculosis of a non-smoking 30-year-old immunocompromised male. He suffered from repeated pneumothorax. The basic pathological feature of video-assisted thoracoscopic lung biopsy revealed granulomatous involvement in the respiratory bronchioles with poorly developed epithelioid cells and disruption of elastic fibers. Electron microscopy demonstrated a decrease in elastic fibers and disruption of the epithelial basement membrane of the respiratory bronchiole and no Langerhans cells in the lesion. Autopsy of the lung revealed centroacinar distribution of multiple cystic lesions in the bilateral upper lobe. Almost all cystic walls showed loss of elastic fibers and cysts frequently involved the respiratory and terminal bronchioles, alveolar ducts and, occasionally, alveoli. Some larger cystic lesions revealed communication to the bronchi. The cystic changes in this case of pulmonary tuberculosis may be caused by a check-valve mechanism due to granulomatous involvement of the bronchioles and also by excavation of caseous necrotic material by draining bronchi.     

Basement Membranes in Bronchogenic Squamous Cell Carcinoma: An Immunohistochemical and Ultrastructural Study

Basement membrane (BM) deposition at the interface of tumor cells and stroma was studied in 27 bronchogenic squamous cell carcinomas. Specimens from peripheral and central parts of each tumor were collected. These were frozen, formalin fixed and paraffin embedded or fixed in Karnovsky's fixative, and processed for electron microscopy. With the use of antibodies to type IV collagen and laminin, the BM was visualized by light microscopy with an indirect immunoperox-idase technique. Light microscopic findings were compared to ultrastructural observations. The peripheral parts of the tumors showed continuous BM in a recognizable preexisting alveolar pattern without evidence of invasive growth into the alveolar septa. In contrast, central parts showed highly variable BM deposition ranging from continuous to almost completely absent. Alveolar patterns were not observed in the tumor centers. The stromal compartment of the tumor centers contained many spindle cells with irregular pericellular BM-like material that could be identified ultrastructurally as myofibroblasts. Electron microscopy and immuno-histochemistry yielded virtually identical results. It is concluded that invasive growth in bronchogenic squamous cell carcinomas occurs in central parts of the tumor when the tumor periphery shows expansive growth without invasion of alveolar septa. The situation is different in invasive squamous cell carcinomas originating from other organs because of anatomical differences between the lung and solid organs.     

Long-term prognosis of scar and non-scar cancers of the breast

The prognostic significance of histopathologic classification of ductal breast carcinoma as scar and non-scar types was studied among 311 patients with breast cancer, followed up for a minimum of 22 years after the diagnosis or until death. Ninety-six (31%) cancers were of scar type and they had a more favourable prognosis than the cancers of non-scar type (p = 0.0001). The scar cancers were more often well differentiated (p less than 0.0001), had more pronounced inflammatory cell reaction (p less than 0.0001), less nuclear pleomorphism (p less than 0.0001), less tumor necrosis (p less than 0.0001), and a lower mitotic rate (p less than 0.0001) than the non-scar cancers. It was less common for patients with scar cancer to have axillary lymph node metastases (p = 0.01) and their primary tumor was smaller (p = 0.006). In flow cytometric analysis the scar cancers were more often DNA diploid (p = 0.004) with S-phase fraction below the median (p = 0.0002). In a multivariate analysis the association of cancer with a scar did not appear as an independent prognostic factor, whereas histologic grade (p less than 0.001) and extent of tumor necrosis (p less than 0.001) did. We conclude that the classification of breast cancer as scar and non-scar types has less prognostic value than the conventional histopathologic grading.     

Intraluminal fibrosis and elastic fiber degradation lead to lung remodeling in pulmonary Langerhans cell granulomatosis (histiocytosis X).

To evaluate the morphogenesis of lung remodeling in pulmonary Langerhans cell granulomatosis (LCG; previously called histiocytosis X or eosinophilic granuloma), lung tissues obtained by open biopsy from 62 patients with pulmonary LCG were studied by light and electron microscopy. Tissues from 20 patients were also studied by immunohistochemical methods for the detection of fibronectin, elastin, and S-100 protein, and samples from six patients were studied using OKT6 monoclonal antibody. In early stages of pulmonary LCG, the epithelial lining cells were detached and Langerhans cells, inflammatory cells, and myofibroblasts migrated into intraluminal spaces through gaps in the epithelial basement membranes in and around the granulomatous lesions. In late stages, intraluminal fibrosis led to obstruction of alveolar spaces and airways and to coalescence of alveolar walls in and around the granulomatous lesions. Adjacent to these lesions, irregularly dilated alveoli were found with degraded and disrupted elastic fibers. Together, these observations suggest that intraluminal fibrosis and elastic fiber degradation are important processes of lung remodeling in pulmonary LCG.     

An autopsy study of the structure of the small vessels in biopsies from the lingula and upper and lower lobes: implications for vascular assessment

We examined the structure of the muscular pulmonary arteries in the three lung sites most often used for lung biopsy. In a subset of cases, we also examined tissue from the central portion of the lower lobe. In each vessel we measured the area of intima and muscle media and expressed these data as a percentage of the total tissue area; vessel size was standardized by using the length of the internal elastic lamina. We found that no one biopsy site best represented the arterial structure of the central aspect of the lower lobe. The lingula had greater numbers of arteries which met the criteria for assessment from than did the other biopsy sites. The vessel structure was similar between the lingula and peripheral aspect of the upper lobe, but the lingula had a slightly increased area of muscle media and decreased intima when compared with the superior segment of the lower lobe. This was not a function of vessel size, since the overall cumulative distribution curve of percent muscle divided by length of internal elastic lamina was also shifted between lingula and lower lobe. We conclude that, in the assessment of arterial vascular structure, any of the standardly used biopsy sites can be representative of the lung. Although there may be differences in structure between the sites in individual patients depending on concurrent disease in any of the sites, there is no consistent site effect on vessel structure. If a formal morphometric evaluation of arterial structure is required, the lingula appears to have more vessels which fit the criteria for assessment.     

Considerations on the mechanisms of alveolar remodeling in centriacinar emphysema

Chronic obstructive pulmonary disease is mainly characterized by irreversible airflow limitation, and its major pathological change is alveolar destruction and enlargement, which induces emphysema. In this study, we used stereoscopic microscopy to observe the cut surfaces of 21 surgically resected or autopsied lungs showing centriacinar emphysema. We identified columnar structures of various sizes in the cystic spaces. These columnar structures constituted two types: one that was associated with pulmonary artery and another that was not. We examined these structures in detail by light microscopy and performed statistical analyses. Columnar structures without pulmonary artery showed destruction and accumulation of alveoli, including abnormally aggregated elastic fibers. In contrast, pulmonary architecture was preserved in columnar structures with pulmonary artery. In columnar structures without pulmonary artery, statistically significant correlations were observed between the thickness of columnar structures and size of centriacinar cystic spaces and between the thickness of columnar structures and aggregation of elastic fibers in columnar structures. Electron microscopy showed that the columns were composed of aggregated elastic fibers, collagen fibers, mesenchymal cells, pigmented macrophages, and the alveolar epithelial cells covering them. Immunohistochemistry showed that the aggregated elastic fibers were positive for α-1 antitrypsin. We concluded that columnar structures without pulmonary artery are a hallmark of alveolar wall destruction seen in pulmonary emphysema.     

A case of hepatocellular carcinoma with respiratory failure caused by widespread tumor microemboli

A 76-year-old man with hepatocellular carcinoma (HCC) was admitted to our hospital suffering from rapidly progressing dyspnea. Chest computed tomography on admission merely showed ground-glass patterns in both lung fields without thrombi in the pulmonary trunk. On the third day, pulmonary blood flow scintigraphy was performed because of progression of his dyspnea, and showed multiple defects indicating widespread thrombi in the peripheral pulmonary arteries. He died of respiratory failure on day 13. A needle necropsy revealed the presence of multiple foci of adenocarcinoma nests in the lungs, suggesting venous thrombi from the poorly differentiated HCC. Although HCC frequently metastasizes to the lung, patients with lung metastasis rarely result in respiratory failure. It is well known that some patients with adenocarcinoma including HCC can develop respiratory failure owing to pulmonary tumor thrombotic microangiopathy (PTTM). In our case, however, pathological examination showed widespread tumor microemboli in the lung, but no stenosis or fibrocellular intimal proliferation in the small arteries and arterioles, which are essential findings of PTTM. Although we concluded that the respiratory failure in this case was mainly caused by widespread tumor microemboli, it remains unclear why such dissemination rapidly developed.     

Immunohistochemical distribution of SP-D,compared with that of SP-A and KL-6, in interstitial pneumonias

The immunohistochemical distribution of SP-D was compared with that of SP-A and KL-6 using a monoclonal antibody in lung tissues of 15 cases of collagen vascular disease-associated interstitial pneumonia (CVD-IP), 4 cases of hypersensitivity pneumonitis (CHP), and 6 cases of other diseases to determine their differences in distribution. In this study, the main targets were alveolar epithelial cells, especially those in the regenerating stage, as well as lymph vessels and stroma. The cytoplasm of type II alveolar epithelial cells and Clara cells was positive for SP-D, with sharp margins; interestingly, however, during the process of regeneration large positive cells were intermingled with relatively small negative cells, even in the same row of cells. In sharp contrast, staining for SP-A and KL-6 was positive in the cytoplasm of all the regenerating alveolar epithelial cells, as well as Clara cells. Staining for KL-6 was usually positive in the surface of air spaces in linear fashion. Staining for SP-A was also positive in elastic fibers in vascular walls. In areas of destruction of pulmonary structures, loose stroma and the endothelial cells of lymph vessels as well as their contents were distinctly positive for SP-A and/or KL-6 but not SP-D. Judging from these results in pulmonary tissues of CVD-IP and HP, SP-D might be a marker for maturity of regenerating epithelial cells. Both SP-A and KL-6 were detected in intimate relationship to the stage of regeneration of alveolar epithelial cells and were expressed before SP-D. In addition, the lymph vessels play a very important role in transfer of KL-6 into the bloodstream.     

Increased elastin production in experimental granulomatous lung disease.

In the normal, healthy lung, elastin production is restricted to periods of development and growth. However, elastin expression in the adult lung has been observed in some forms of pulmonary injury, including pulmonary fibrosis. Here, we report that elastin production is significantly increased within precise interstitial compartments of the lung in an experimental model of granulomatous lung disease. An increase in the number and volume of elastic fibers within the alveolar walls was apparent on histological examination of Verhoeff-van Gieson-stained sections of silicotic rat lungs. Quantitation of mature elastin cross-links indicated that silicosis was accompanied by a 17-fold increase in lung elastin content when compared with values from saline-treated controls. In situ hybridization for tropoelastin mRNA revealed that elastin production was absent from granulomatous lesions yet was prominent at nonfibrotic alveolar septal tips, where a high density of elastic fibers is seen in the normal lung. Immunohistochemistry indicated tropoelastin was being expressed by alpha-smooth muscle actin-containing cells. Transforming growth factor-beta was immunolocalized to granulomatous regions of the silicotic lung but was absent from regions showing increased tropoelastin expression. These data indicate that the reinitiation of tropoelastin gene expression is associated with granulomatous lung disease, and this expression leads to the aberrant accumulation of mature elastin in the lung.