Myofibroblasts and related cells in malignant fibrous and fibrohistiocytic tumors.

Myofibroblasts were detected by electron microscopy in five of five cases of fibrosarcoma and in five of six cases of malignant fibrous histiocytoma. In some areas myofibroblasts constituted up to 75 per cent of the tumor cells. Most myofibroblasts contained only sheaves of myofilaments along the margins of the cells, but some cells contained larger bundles of myofilaments and very closely resembled smooth muscle cells. An additional related type of cell was seen in several cases; it was large and possessed abundant eosinophilic cytoplasm, resembling a rhabdomyoblast at the light microscopic level. By electron microscopy this type of cell was seen to contain plentiful rough endoplasmic reticulum and large aggregates of fine filaments with rare dense bodies. These findings suggest that fibrosarcomas and malignant fibrous histiocytomas contain cells showing a spectrum of differentiation from fibrocytic to myogenic and that at the ultrastructural level the distinction between fibroblast and smooth muscle tumors may be blurred.

Numbers of asbestos bodies in urban patients with lung cancer and gastrointestinal cancer and in matched controls.

We compared the numbers of asbestos bodies extracted from the lungs of 103 patients with lung cancer and 50 patients with gastrointestinal malignant neoplasms to the numbers of bodies extracted from lungs of control patients matched for age, sex, smoking habits, and, in some cases, occupation. All patients were urban dwellers over the age of 40 years, and none was a primary asbestos worker. No differences in the counts of asbestos bodies were observed between the tested and control populations. The numbers of asbestos bodies did correlate well with occupation; the highest counts were found in male manual laborers. We conclude that in the urban population studied herein, the numbers of asbestos bodies alone do not correlate with the presence of pulmonary or gastrointestinal carcinoma; however, uncoated asbestos fibers are also known to be present in the lung, and the possibility that such tumors may be related to the numbers of these fibers in lungs remains to be explored.

Correction of congenital diaphragmatic hernia in utero. II. Simulated correction permits fetal lung growth with survival at birth.

Infants with congenital diaphragmatic hernia (CDH) die because their lungs are hypoplastic. If hypoplasia is a developmental consequence of compression by herniated viscera, decompression before birth may allow pulmonary development and survival at term. A conical silicone rubber balloon progressively inflated (60 to 150 ml) in the left hemithoraxi of fetal limbs (days 100 to 145) simulated compression by growing viscera ("CDH"). Six of six neonates delivered by cesarean section died of severe respiratory insufficiency, despite maximal resuscitation. Lungs were hypoplastic. Lung weight and air capacity were significantly reduced (P less than 0.01) as compared with controls. Pressure-volume curves revealed decreased compliance and barium gelatin injections revealed decreased cross-sectional area of the pulmonary vascular bed. Deflation of the balloon at day 120 (simulated "correction") allowed sufficient lung growth and development to alleviate respiratory insufficiency and to assure survival in five of five lambs delivered by cesarean section. Simulated correction produced a significant (P less than 0.01) increase in lung weight, air capacity, compliance, and area of the pulmonary vascular bed. Efficacy of in utero correction was confirmed by three twin studies in which simulated CDH in one twin was compared with simulated correction in the other. Infants with CDH may be salvaged by in utero correction.

The significance of pulmonary changes associated with cerebral perfusion with hypoxic blood in monkeys.

Parameters of cerebral and pulmonary function were studied in ten animals whose brains were perfused with hypoxic right atrial blood according to the Moss method. All animals died as a result of cerebral hypoxia at about 95 minutes after the onset of perfusion. Gross pulmonary congestion, edema, and leukocyte plugs occurred in the seven animals breathing spontaneously, but positive pressure ventilation prevented these changes in three. The resumption of cerebral perfusion with oxygenated blood after 30 minutes of the Moss procedure did not prevent the pulmonary changes and, of more importance, did not prevent cerebral swelling and death at about the same time as that of all the other animals. There were no changes in oxygen uptake or in arterial oxygen tension to indicate that progressive pulmonary failure contributed to death. It is concluded that this model produces brain swelling and brain death with incidental pulmonary pathological changes indistinguishable from early findings in hemorrhagic shock models and that the cerebral hypoxic perfusion model in monkeys is not suitable for studying the effects of "shock lung" therapy.

Production of acute pulmonary injury by leukocytes and activated complement.

The adult respiratory distress syndrome (ARDS) frequently occurs after sepsis and major trauma. Since both sepsis and trauma may cause activation of the complement system, we have infused rabbits with complement-activated plasma (AP) and have studied the effects on leukocyte counts, respiratory rate, PaO2, and lung morphology. Sustained AP infusion caused: (1) early granulocytopenia, (2) progressive hypoxemia and tachypnea, and (3) pulmonary vascular plugging by aggregates of degenerating granulocytes with interstital edema and endothelial injury. These changes were not observed in control animals infused with unactivated plasma or in animals rendered leukopenic with nitrogen mustard. Complement activation in patients with sepsis and trauma may be an etiologic factor in the development of ARDS.

Changing trends in US mesothelioma incidence.

AIMS: To report the temporal pattern and change in trend of mesothelioma incidence in the United States since 1973. METHODS: The Surveillance, Epidemiology, and End Results (SEER) programme of the National Cancer Institute has since 1973 provided annual age adjusted incidence for mesothelioma in representative cancer registries dispersed throughout the USA. SEER data are analysed to describe the trend of male mesothelioma incidence in the USA. RESULTS: The US male mesothelioma incidence data indicate that after two decades of increasing incidence, a likely decline has been observed since the early 1990s, when a highly significant change in the upward course occurred. CONCLUSIONS: Increasing male mesothelioma incidence for many years was undoubtedly the result of exposure to asbestos. The high mesothelioma risk was prominently influenced by exposure to amphibole asbestos (crocidolite and amosite), which reached its peak usage in the 1960s and thereafter declined. A differing pattern in some other countries (continuing rise in incidence) may be related to their greater and later amphibole use, particularly crocidolite. The known latency period for the development of this tumour provides biological plausibility for the recent decline in mesothelioma incidence in the USA. This favourable finding is contrary to a widespread fear that asbestos related health effects will show an inevitable increase in coming years, or even decades.

Asbestos and other ferruginous bodies: their formation and clinical significance.

Analyses of asbestos bodies from the general population have confirmed that these structures, like asbestos bodies from the lungs of asbestos workers, contain an asbestos core. In members of the general population this core is almost always an amphibole, whereas asbestos workers may have bodies formed on either amphibole or chrysotile. Most adults have a few bodies, and increasing numbers are seen in blue collar workers and others who handle small amounts of the fiber, with the highest levels being seen in asbestos workers. In men with minimal or extensive occupational exposure, asbestos bodies are formed on the commercial fibers, amosite and crocidolite, whereas women also form a significant number of bodies on the noncommercial fibers, anthophyllite and tremolite. These findings suggest that women may be exposed to specific asbestos-containing products, eg, cosmetic talc. The commercial fibers found in women and white collar men probably reflect atmospheric pollution with asbestos. At the highest levels of exposure, numbers of asbestos bodies correlate in a general way with the presence of asbestosis, although no precise value has been determined above which asbestosis is always found. In persons with much lower or environmental exposure, there does not appear to be any correlation between numbers of bodies and disease, in particular between numbers of bodies and carcinoma of the lung or gastrointestinal tract. The situation for mesothelioma is uncertain.

The ultrastructure of pulmonary hamartoma.

Ultrastructural and histochemical examination of chondromatous pulmonary hamartomas revealed the epithelial component to be comprised elements similar to those lining the distal bronchioles and the alveoli of adult lung. The stromal cells nearest the epithelium include a population resembling mature fibroblasts and a population of glycogen-containing, primitive appearing cells. More deeply situated stromal cells showed features of chrondroid differentiation.

Analysis of the cores of ferruginous (asbestos) bodies from the general population. III. Patients with environmental exposure.

Typical asbestos bodies visible by light microscopy were isolated from the lungs of 29 persons with fewer than 100 such bodies per gram of lung, a level that is considered indicative of environmental rather than occupational asbestos exposure. Of 144 bodies examined by electron diffraction, 143 contained an amphibole asbestos core and one contained a chrysotile asbestos core. Thirty-five bodies from 21 patients were also analyzed by electron microprobe. Of these, 21 were chemically consistent with amosite or crocidolite asbestos, 13 with anthophyllite asbestos, and one with tremolite asbestos. Certain differences in chemical fiber types between men and women became apparent. Although cores of amosite and crocidolite predominated in men (12 of 14, 86 per cent), anthophyllite and tremolite comprised 57 per cent (12 of 21) of the cores found in women, a statistically significant difference. These differences suggest that the major commerical varieties of amphibole asbestos (amosite and crocidolite) are the source of the fibers in men, whereas in women a major source may be cosmetic talc, which is often contaminated with anthophyllite and tremolite. On the basis of this study and our previous studies, we conclude that almost all typical asbestos bodies from the lungs of the general population contain an amphibole asbestos core.

Association of asbestos and bronchogenic carcinoma in a population with low asbestos exposure.

Quantitative counts of ferruginous bodies were performed on digests of lungs from 100 control and 30 lung cancer patients. It was found that the lung cancer group had significantly higher levels, although only 1 patient was known to be occupationally exposed to asbestos. It is suggested that even extremely low levels of asbestos exposure may have a carcinogenic effect.

So-called "minute pulmonary chemodectoma": a tumor not related to paragangliomas.

Twenty-six cases of so-called "minute pulmonary chemodectoma" are presented. The patient population showed a marked female preponderance, and there appeared to be an association of the lesion with pulmonary injury from a variety of causes including cardiac failure, chronic bronchitis and emphysema, and thromboemboli. Half the cases had multiple tumors. Microscopically, the tumors consisted of nests of cells in the interstitial tissue near small veins. Argentaffin and argyrophil stains failed to demonstrate cytoplasmic granules in any case. By electron microscopy, the nests were composed of large cells with broadly interdigitating processes connected by many well-formed desmosomes. The cytoplasm was filled with numerous 60-A filaments. The Golgi apparatus was prominent, while other organelles were sparse. No secretory granules were identified. It is concluded that the fine structure and lack of silver-positive granules are inconsistent with the morphology of previously reported paragangliomas, but that there is a resemblance at the light and electron microscopic level to meningeal arachnoed cells and the cells of meningiomas.

Abscess formation in recurrent liposarcomas of the abdomen and retroperitoneum: relevance to treatment.

Stimulated by the unexpected finding of gross abscesses in two cases of abdominal liposarcoma, we initiated a retrospective study to determine the incidence of this finding. Sixteen patients were analyzed, and correlations were made between histologic features and clinical course. Microscopic or macroscopic evidence of abscess was present in four cases. There appears to be an association between tumor necrosis or abscess and tumors with prognostically poor histology (e.g., pleomorphic tumors). Clinicians who treat patients with these tumors should be aware of the substantial risk of abscess and modify their therapy accordingly.

Unusual roentgenographic presentation of a congenital cystic malformation of the lung.

We describe here an infant with a large, solitary, fluid-filled lung cyst and hyperinflation of adjacent lung tissue in the same lobe. The combination of a fluid-filled cyst and ectatic emphysema in the same lobe suggests bronchial collapse and airway obstruction as a contributory mechanism for this unusual roentgenographic presentation of a congenital cystic malformation of the lung.

Pulmonary alveolar proteinosis and aluminum dust exposure.

A 44-yr-old male presented with shortness of breath, diffuse X-ray infiltrates, and physiologic evidence of a restrictive lung disease. Biopsy revealed pulmonary alveolar proteinosis. The patient had worked for the previous 6 yr as an aluminum rail grinder in a very dusty environment. Analysis of his lung tissue revealed greater than 300 X 10(6) particles of aluminum/g dry lung; all of the particles appeared as spheres of less than 1 mu diameter. We believe that this case represents an example of pulmonary alveolar proteinosis induced by inhalation of aluminum particles; this finding confirms animal studies which suggest that proteinosis can be produced by very large doses of many types of finely divided mineral dust.

Fly ash lung: a new pneumoconiosis?

A laborer who worked in a steel mill and in a shipyard developed a nonspecific pulmonary interstitial fibrosis. Postmortem samples of his lung were digested, and the inorganic material present was extracted and examined using transmission electron microscopy, electron diffraction, and electron microprobe analysis. Uncoated asbestos fibers were present (1.4 X 10(5)/g wet lung), but the surprising finding was the presence of a large number of fly ash particles (6 X 10(6)/g wet lung). Fly ash, the particulate material produced during coal combustion, has not previously been reported to be present in human lung tissue. Although the contribution of the asbestos to this man's lung disease is uncertain, we believe, based on previous studies implicating aluminum silicates in pneumoconiosis, that the fly ash, an aluminum silicate, may be a contributing factor.