SUMMARY Mast cells were identified by electronmicroscopy in the alveolar wall of the lung in 20 subjects (10 normal, 10 abnormal). A quantitative and qualitative study was made of the mast cells. In the normal lung there was an average concentration of 350 mast cells/mm2 of alveolar wall and in the abnormal 523/mm2. Mast cells occupied approximately 1-6-2-1 % of the area of the alveolar wall. There was marked variation in the structure of the mast cell granules but no differences between those in the normal and abnormal lungs. There was evidence that constant degranulation of mast cells may be occurring in the lung. The role that alveolar mast cells may play in the vasoconstrictor response to alveolar hypoxia is discussed. It is suggested that the tachypnoea present in asthma may partly be due to release of mediators from sensitised mast cells within the alveolar wall.It has been generally thought that mast cells in the human lung are found deep to the bronchial mucous membranel 2and also around blood vessels particularly venules deep in connective tissue. 3 During the course of routine electronmicroscopic study of human lungs we were suprised to see mast cells within the alveolar wall. We therefore studied systematically by electronmicroscopy both qualitatively and quantitatively the distribution of mast cells within alveoli in normal and abnormal human lung tissue. Material and methodsLung tissue was obtained by thoracotomy from 20 patients of which lung disease was present in 10 ( Table 1). The assessment of disease in the lung was made by examining paraffin sections of lung tissue adjacent to the areas from which the sections for electronmicroscopy were taken. A piece of lung tissue (about 1 cm x 1 cm x 0-5 cm) was taken immediately after the specimen was removed, and placed in Karnovsky fixative at 4°C: after one hour the tissue was cut into pieces approximately 2 mm x 2 mm x 1 mm and allowed to fix for a further three hours. The specimens were washed overnight in cacodylate-sucrose buffer at 4°C, then postfixed in 1 % osmium tetroxide for one hour at 4°C. This was Accepted for publication 6 May 1981 followed by washing in distilled water for five minutes and block staining in 2 % aqueous uranyl acetate for one hour. The tissue was dehydrated to absolute alcohol and placed in two changes of epoxypropane for 15 min each, and then in warmed (60°C) Araldite for one hour. The tissue was then embedded in fresh Araldite at 600Cfor at least 48 h. Sections were cut at 2 ,urm, stained with toluidine blue, and areas showing alveolar walls were selected for ultrathin sections. These were then cut with gold interferencecolourmounted on G200 HT copper grids and contrasted with 2 % uranyl acetate and lead citrate and examined in a Philips EM 201.

Nineteen cases of mucinous carcinoma of the breast were studied. Twelve tumours were of the pure type, and seven were mixed. All had abundant neutral and acidic mucin, and stained strongly with CAM 5.2. Of the 12 pure mucinous tumours, six were devoid of argyrophilic granules and were S-100 negative, and only one was CEA positive. All six patients are alive with no evidence of recurrence (mean follow-up 42 months). The other six pure mucinous tumours were rich in argyrophilic granules. Five of these showed S-100 positivity and all were CEA positive. One patient developed local recurrence and one died of myocardial infarction with no evidence of tumour recurrence (mean follow-up 80 months). Of the seven mixed tumours, only one contained an occasional cell with argyrophilic granules and four had variable degrees of CEA positivity. Two patients died and one developed bony metastasis (mean follow-up 40 months). Our findings emphasise the microscopic and prognostic differences between the three subtypes of mucinous carcinoma of the breast, and support the concept of dividing pure mucinous tumours into two distinct subtypes. We suggest that the latter subtyping can be qualitatively made on the basis of the presence or absence of argyrophilic granules in the tumour cells.

We report the pathological changes in liver biopsies from 10 patients (four female transexuals and six impotent males) after treatment with 150 mg methyltestosterone daily for periods of up to 3 years, and in a hemihepatectomy specimen from a female transexual who developed a liver adenoma after 37 months of this treatment. Hepatocyte hyperplasia and mild focal sinusoidal dilatation was found in most cases. In some cases there were microcysts and dissociation of hepatocytes. In nine patients there was accumulation of hepatocytes between the endothelium and the supporting collagen of hepatic veins which often resulted in either partial occlusion of their lumina or disruption of their walls. These vascular changes do not appear to have been reported before. It is postulated that a single pathological process-hyperplasia, perhaps related to the anabolic effect of methyltestosterone--could be partly responsible both for the formation of cysts through mechanical obstruction of hepatic veins and for the formation of nodules and tumours.

SUMMARYThe electron microscopic structure of cilia from the inferior turbinate of the nose was studied in 12 adults, four with chronic sinusitis, one with allergic rhinitis, two with bronchiectasis, three with deviated nasal septum, and two normals. The changes are compared with those found in nasal cilia in 14 patients with retinitis pigmentosa.There were compound cilia in the seven cases with chronic sinusitis, allergic rhinitis, and bronchiectasis but, apart from this, the structure of the cilia was similar in all 12 cases. There were variations in the microtubular pattern in about 4 % of cilia, dynein arms were not seen in 4 %, and in the rest an average of 5-6 dynein arms were seen in each cilium. The orientation of the cilia was 0 to 900.In the retinitis pigmentosa patients there was a highly significant increase in cilial abnormalities.The establishment on a quantitative basis of the variations in normal structure of nasal cilia facilitated the recognition of an association between cilial abnormalities and retinitis pigmentosa and should help in the identification of associations that may exist between cilial abnormalities and other diseases.In a recent study of ultrastructural abnormalities in nasal cilia in retinitis pigmentosa' we found it essential to establish in some quantitative form the type and range of abnormalities present in nasal cilia from a group of control subjects. This information will also be useful in the investigation of chronic lung diseases2-6 and sterility in men,7 8 in which there are known abnormalities in cilia, and should enable one to recognise associations of cilial abnormalities with other diseases.The electron microscopic structure of normal cilia and various abnormalities found are described, and quantitative measurements of the various changes are made and compared with those found in patients with retinitis pigmentosa. Subjects studied and methodsTwelve subjects (8 men, 4 women) were studied: two healthy volunteers, three patients with deviated

No abstract