Central lymph node changes and progressive massive fibrosis in coalworkers.

Lungs from 123 coalworkers coming to necropsy were examined to determine the association between dust related changes in the central lymph nodes and progressive massive fibrosis and secondary foci in the lung parenchyma. Increasingly extensive changes of the central nodes were scored macroscopically, the highest scores indicating erosion through the walls of adjacent bronchi or branches of the pulmonary artery or both. In 88 cases (mainly with extensive changes) microscopic assessment was also made. Increasingly extensive changes of central nodes were associated with the presence of progressive massive fibrosis in the lungs (p less than 0.001) and the presence of secondary foci in lungs without progressive massive fibrosis (p less than 0.03). Microscopic assessments agreed fairly well with macroscopic assessments, but tended to be assigned lower scores. A hypothesis for the pathogenesis of progressive massive fibrosis is proposed whereby dust, accumulating in central lymph nodes, leads eventually to spread through the capsule and rupture into bronchi or pulmonary vessels, thereby sending dust laden activated cells back into the lungs to produce progressive massive fibrosis. These preliminary results are consistent with the hypothesis but more detailed studies are required.

Post-mortem study of emphysema in coalworkers and non-coalworkers.

A post-mortem survey of emphysema in coalworkers and non-coalworkers was carried out in men aged 50-70 years dying of ischaemic heart disease (IHD). It was determined that in such men selection for necropsy was similar in coalworkers and non-coalworkers. All lungs were examined in a standard way and the amounts of centrilobular and panacinar emphysema were scored on numerical scales. Emphysema in men dying of IHD was significantly more frequent in coalworkers than in non-coalworkers even after age and smoking habits were accounted for by stratification. In the coalworkers, the severity of emphysema was related to the amount of dust in simple foci in the lungs. Because both groups were selected similarly from their parent populations the relative frequency of emphysema found in this study reflects that in the whole populations of coalworkers and non-coalworkers in the study area and confirms an excess of emphysema in coalworkers. This excess is likely to be due to occupational factors.

Emphysema in smoking and non-smoking coalworkers with pneumoconiosis.

The relationships between coalworkers' pneumoconiosis, cigarette smoking and emphysema in a group of 139 deceased coalminers, 19 of whom were non or ex-smokers of 10 years standing, were studied from available clinical and morphological evidence. There was 95 cases of simple pneumoconoiosis and 44 cases with early (Cat. A) progressive massive fibrosis (PMF). The objects were to compare the amounts and types of emphysema in the smokers and non-smokers and also their ventilatory findings. The emphysema content of all the 139 cases of smokers and non-smokers was measured by a standard method and the amounts compared. In addition, the emphysema content of the 19 non- and ex-smokers plus 32 appropriate control cases drawn from the smoking group were measured afresh by a new method devised by the pathologists for the estimation of the extent and type of both emphysema and coalworkers, pneumoconiosis, from large paper lung sections and histological preparations. Both methods compared well in estimating emphysema content and both indicated that the amounts of emphysema in the smoking and non-smoking groups were similar. These findings still applied when both the life-long non-smokers and the cases with simple pneumoconiosis only were looked at separately. It was found that centrilobular emphysema was much commonest type encountered in both smokers and non-smokers. The non-smokers were less disabled in terms of impairment of FEV1.0 than the smokers, although the difference was not statistically significant. The relationship between the centrilobular emphysema and coalworkers' pneumoconiosis is discussed.

Current views on pathological aspects of asbestosis (the unresolved questions and problems).

The present criteria for the diagnosis of asbestosis are discussed, as are previous attempts to correlate the pathological with the clinical and radiological findings and the problem of the variable distribution of asbestos forms in routine sections taken from undoubted cases of asbestosis. Establishing lesser degrees of asbestosis is important, and lower limits need to be defined. Evidence is presented, with illustrative examples, of the value of concentration techniques; even for diagnostic purposes there is occasionally a need for more sophisticated electron microscopy techniques. The occurrence and the extent of diffuse interstitial inflammatory changes as part of the biological effects of asbestos exposure are illustrated; and the difficulties inherent in cases where there has been exposure to other dusts as well as to asbestos are described.

Primary lymphoproliferative conditions of lung.

The clinical, laboratory, and pathological features of six primary lymphoproliferative conditions of the lung are described. These comprise two patients with malignant lymphomas, one with pseudolymphoma, one with lymphoid interstitial pneumonia (LIP), one with lymphomatoid granulomatosis, and one with plasma cell granuloma. We recommend that the term 'premalignant lymphoma' be used for pseudolymphoma since the condition, although tending to remain localised, has a malignant potential. A combination of dyspnoea, cough, and pyrexia were the presenting features in our cases of premalignant and malignant lymphoma although they may often be discovered accidentally by chest radiography. The patient with LIP presented with the usual symptoms of dyspnoea and cough. The initial manifestations of the patient with lymphomatoid granulomatosis were skin radh and peripheral neuropathy nine months before the pulmonary symptoms, a not unusual occurrence. Plasma cell granuloma is often asymptomatic but our patient presented with cough, chest pain, haemoptysis. Premalignant lymphoma tends to pursue a benign course although exceptionally it may become disseminated. Malignant lymphoma may remain localised for many years but a significant proportion metastasise. Lymphomatoid granulomatosis and LIP have a varied course but both may terminate in malignant lymphoma. Plasma cell granuloma is always benign. The interrelationships of these conditions and their differential diagnosis are discussed.

Lymphosarcoma in Crohn's disease: report of a case.

In a patient who had a family history of ulcerative colitis and colonic carcinoma, a jejunal lymphosarcoma developed four years after resection for Crohn's disease of the small intestine. It is suggested that the association of lymphosarcoma with Crohn's disease is more than a chance association.

Aspergillus prosthetic valve endocarditis.

The clinical, laboratory, and histopathological features of seven cases of Aspergillus fumigatus prosthetic valve endocarditis are presented. The exact nature of the lesion, a combination of infective fungal endocarditis and thrombosis on the prosthetic valve, is discussed and the difficulties in clinical diagnosis are emphasized. Helpful indications were sudden unexplained heart failure with the appearance of new murmurs, and emboli to large or medium-sized systemic arteries. Fever and anaemia were inconstant, and in no case was blood culture or precipitin investigation helpful. Spore contamination of operating theatre air was the likely source of infection, and measures taken to overcome this and other predisposing factors are discussed. Since medical diagnosis is usually late and the few reported cures in this condition have included replacement of the prosthesis, early surgical intervention combined with antifungal chemotherapy is advised.

Hypersensitivity pneumonitis after exposure to isocyanates.

Four patients exposed to isocyanate vapour developed dyspnoea associated with restriction and reduced gas transfer as well as moderate airways obstruction on lung function testing. In one patient bilateral radiographic shadowing was present and an open lung biopsy was performed. The microscopic appearances ranged from acute inflammation to end-stage fibrosis but the centribular accentuation of disease and the presence of areas resembling bronchopulmonary aspergillosis suggested that the process was a hypersensitivity response to inhaled allergen. Challenge tests with albumin and toluene diisocyanate-albumin were carried out in sensitized and control rabbits. The sensitized animals developed extensive lung damage of the type associated with an Arthus reaction. It is suggested that patients exposed to isocyanates may occasionally develop a hypersensitivity pneumonitis rather than the more usual asthmatic syndrome.

Pulmonary responses to particulate materials capable of activating the alternative pathway of complement.

The cellular sequence of events evoked by the intratracheal injection of both respirable mouldy hay dust and zymosan in unsensitized rats and rabbits was markedly similar and contained many features seen in lung biopsies from farmer's lung cases. It is considered that a combination of ability to activate the alternative pathway of complement and the particulate nature of mouldy hay dust and zymosan produced the pulmonary response seen and as such, considerable insight has been gained into mechanisms by which unsensitized individuals respond to dust inhalation. It is suggested that alternative pathway activation may produce an attack of farmer's lung in the absence of precipitins or other forms of hypersensitivity to the dust or its components and that cases designated as 'pulmonary mycotoxicosis' are more rationally explained by this mechanism.