Necrotizing sialometaplasia of the lip simulating squamous cell carcinoma

A case of necrotizing sialometaplasia of the lip in an 68-year-old pipe smoker is described. Necrotizing sialometaplasia is a self-healing non-neoplastic disease probably of ischaemic nature. Thirty-nine cases of sialometaplasia are described in the literature up to early 1979. These cases appeared in the palate, nasal cavity, gingiva, lip, hypopharynx and maxillary sinus. Six cases have also been reported from major salivary glands. Histologically there is necrosis of mucous cells with partial replacement by squamous epithelium. This entity has often been mistaken for squamous or mucoepidermoid carcinoma. One has to be familiar with the existence of necrotizing sialometaplasia in ordeg surgery.

Squamous metaplasia of the endometrium. Endometrial response to intrauterine presence of fibroblast-carrying Ivalon sponge

Squamous metaplasia of the endometrium was detected in 3 women out of ten in which fibroblast-carrying Ivalon sponge (produced by implanting the sponge subcutaneously for 6 to 8 weeks) was inserted into the uterus following dilatation and curettage. The experiments were carried out in view of previous successful similar procedures in rabbits to produce fibroblastic bridges inside the uterus, and to avoid the patients from undergoing major surgery (hysterectomy) if possible, and at the same time to use the experiment as a model of contraception procedure. Since no improvement was experienced by the patients, which continued to have excessive blood loss, hysterectomies were performed at a later date, and the specimens were thoroughly examined. The possible effect of the Ivalon sponge (acting as IUCD) on the endometrium is discussed.

Histological appearances of the gastric mucosa 15--27 years after partial gastrectomy

Sixty-three patients, who had had a partial gastrectomy 15--27 years previously, were examined by endoscopy and multiple mucosal biopsies. No patient had a completely normal gastric mucosa; they showed varying degrees of gastritis, intestinal metaplasia, and dysplasia: 21% had significant dysplasia, and these are regarded as an 'at-risk' group requiring frequent follow-up examinations. One patient had severe dysplasia (carcinoma-in-situ), but no case of infiltrating carcinoma was found.

Pulmonary carcinogenesis in rats given implants of cigarette smoke condensate in beeswax pellets

Lungs of inbred OM/NCR and outbred Sprague-Dawley rats were given implants, through a thoracotomy, of pellets of cigarette smoke condensate (CSC) suspended in a beeswax-tricaprylin vehicle. The pellets slowly released material into the surrounding parenchyma, which resulted in a dose-related increased incidence of lung cancer, predominantly invasive and metastasizing epidermoid carcinoma. A 42% prevalence of pulmonary carcinoma was present in the highest dosage group, which received 67 mg CSC, exposing approximately 1.65 cm2 bronchiolar epithelium. Squamous metaplasia associated with the implanted site preceded the appearance of the carcinomas and was more severe, with the larger pellets having more concentrated CSC. No difference was observed in incidence of pulmonary carcinomas with the use of CSC containing high or low concentrations of nicotine. The potential value of this bioassay system were discussed.

Inhalation toxicity studies on cigarette smoke (VI). 6-week comparative experiments using modified flue-cured cigarettes: histopathology of the lung

Rats were exposed twice daily for 6 weeks to diluted smoke derived from cigarettes with a range of deliveries of particulate matter. The inhaled smoke reached the alveolar surface, increased the size and number of free macrophages and provoked epithelial metaplasia but did not appear to alter the lymphoid reaction to spontaneous infection. The hypertrophy of the macrophages was typically alveolar and their hyperplasia was directly proportional to the particulate delivery of cigarettes smoked. Alveolar metaplasia was incipient, developed characteristically near the respiratory bronchiole in close association with macrophage clusters and only in rats exposed to smoke from cigarettes with the highest delivery of particulate matter.

Experimental canine tracheal grafts with reversible squamous metaplasia

A technique for making bistomal tracheal pedicle grafts in dogs is described. The grafts were placed subcutaneously in the neck, and their mucosa was readily accessible to serial manipulations, endoscopic examinations, and biopsies, without requiring anesthesia. Squamous metaplasia developed in 5 of 8 grafts, or 63 per cent, within 1 week. Within 12 weeks, squamous metaplasia was seen in all grafts, and it was consistently accompanied by basal hyperplasia. After orthotopic reimplantation of the grafts, the squamous metaplasia proved to be reversible within 4 weeks. The preparation used for making these observations is a valuable research tool for sequential studies of the respiratory tract mucosa.

Squamous epithelial cancer in metaplastic pleura following extrapleural pneumothorax for pulmonary tuberculosis

During the period 1947-1955, 148 patients underwent extrapleural pneumolysis for pulmonary tuberculosis in Stockholm City Chest Hospital at Söderby. In 121 tuberculosis healed following operation. Ten of these later developed pain and a feeling of tension on the operated side and were operated upon with evacuation of the extrapleural sac. In four of them a highly differentiated keratinizing aquamous cell carcinoma had developed. In addition, two more cases of carinomas of the same type operated on at other hospitals are described. Five of the six patients died of cancer. Squamous cell carcinoma occurring in metaplastic mesothelial cells has hitherto not been reported on and the phenomenon is discussed and compared with the more common scar cancers within lung tissue caused by damage from tuberculosis.

Squamous metaplasia of the tracheal epithelium in children

Thirty-seven (1-6%) tracheas from 2170 children showed squamous metaplasia. (Cases with tracheo-oesophageal fistula and congenital heart disease were excluded). The metaplasia extended into the bronchi in 15 cases. Features of pulmonary retention were present in seven cases. Respiratory infection, probably viral, seemed to be the most significant causative factor in 20 children, including those with cystic fibrosis. Tracheal instrumentation was a possible factor in 11 cases but oxygen therapy alone did not seem important. The metaplasia was almost certainly congenital in one child and probably in two others but no stillborn infants showed metaplasia. In many children the metaplasia seemed to be due to a combination of factors.

[Bronchioloalveolar metaplasia during experimental influenza in mice--histological and ultrastructural study]

Squamous and "adenomatous" metaplastic changes which developed in the lungs of mice during the healing phase of experimental influenza were studied by histology and electron microscopy. The squamous nests contained epithelial cells possessing bundles of tonfibrils and being similar to bronchial basal cells. The "adenomatous" cavities were lined, either by cells related to Clara cells or by basal type-cells, which underlined cells related to Clara cells. A local and transitory hyperplasia of type II pneumocytes occurred by the third week. Both kinds of metaplasia seemed to proceed from the bronchial or bronchiolar epithelium. The adenomatous cavities might partly result from progressive differentiation of squamous epithelial cells into cells of glandular type. A ten-month long histologic survey failed to exhibit carcinomatous transformation of metaplasia. Pleiomorphism of influenza regenerative metaplasia might arise from extensive and severe epithelial changes involving all levels of the lower respiratory tract. Such a long persistence of metaplastic changes remains unexplained.

Endometrial ossification

Irregular growth of bone was seen in endometrial tissue curetted from a 41-year-old woman, 12 months after an abortion. Bone was present in a second specimen taken later. On hysterectomy 22 months after the abortion, no trace of the abnormal tissue was found. The heterotopia is considered to be due to metaplasia occurring in cells initially concerned in the post-abortion reparative process.

Surface alterations due to endotracheal intubation

The varied complication of prolonged endotracheal intubation, including tracheal stenosis, stricture and tracheomalacia, are thought to be directly related to lateral tracheal wall pressure. To investigate the initiation, relevance and duration of these changes, studies were undertaken to assess the effects of intubation on the surface anatomy of the trachea by scanning electron microscopy. Tracheal mucosal morphology was studies in (1) anesthetized "normal" dogs; (2) d-ogs sacrificed 2 hours after intubation with cuff deflated or inflated to the "just seal" point using a cuff system producing the lowest tracheal wall pressure; and (3) dogs intubated for 2 hours and then examined at 2 and 7 days after extubation. Intubation without cuff inflation resulted in distinct linear areas of nearly complete ciliary denudation along the tract of tubal insertion within 2 hours. Inflated cuffs produced similar but more widespread changes especially over tracheal rings, indicating that pressure in areas of least resiliency significantly contributes to these alterations. Regeneration of cilia could be seen 2 days after extubation, but many anatomic features remained distorted; at 7 days, regeneration was nearly complete, but isolated areas of denudation could still be identified. Scanning electron micrographs of human tracheas taken at autopsy from patients who had had prolonged intubation with the same cuff system correlated well with those obtained from dogs.

Leprosy of the upper respiratory tract. A clinical bacteriological, histopathological and histochemical study of twenty cases

Twenty cases clinically diagnosed as leprosy were thoroughly examined for E.N.T. lesions. These lesions were subjected to bacteriological, histopathological and histochemical studies. The results have been tabulated and discussed with special stress on some findings which are of help in diagnosing the disease.

Mucous metaplasia and gap junctions in the vitamin A acid-treated skin tumor, keratoacanthoma

Desmosomes are the usual cell junctions found in normal rabbit epithelium as well as in the untreated keratoacanthoma. This study reports the finding of a second cell junction, the gap junction, when epithelium, normal or tumorous, is subjected to topical applications of vitamin A acid. The gap junction forms early in mucous metaplasia (after 2 days of application of vitamin A acid) and appears before the gross appearance of mucus. The presence of the gap junction occurs when there is an increase in the rough-surfaced endoplasmic reticulum and Golgi cisternae and vesicles. It is possible that the early appearance of the gap junction facilitates and mediates the mucous metaplasia. This suggestion is strengthened by the fact that the gap junction, once present in the mucus-producing tumor, is sparse when the tumor reverts back to the dry, keratotic condition upon cessation of vitamin A acid applications.

Erosive gastritis with special reference to the role of aspirin and bile

The high mortality associated with the surgical treatment of erosive gastritis is related to the postoperative continuing haemorrhage rate. Immediate gastroscopy has significantly improved preoperative diagnosis, and in 30 cases treated by the Billroth I operation continuing haemorrhage was seen on only one occasion.The frequent association of chronic gastritis and drug-associated erosive gastritis suggests that the gastritic mucosa is unusually susceptible to aspirin. Experiments designed to investigate the effect of biliary diversion on aspirin-induced gastric mucosal damage demonstrated a significant increase in such damage.Intestinal metaplasia and chronic gastritis of the gastric mucosa develop when upper intestinal secretions are diverted into the stomach either surgically or by pyloric regurgitation. Postoperative gastric aspiration indicates that the Billroth I operation is associated with far less regurgitation of upper intestinal secretions postoperatively than either the Polya operation or vagotomy and drainage. It is suggested that the efficacy of the Billroth I operation in controlling haemorrhage in the immediate postoperative period is related to this. In the long term the reduced incidence of intestinal metaplasia in the Billroth I gastric remnant reflects a minimal tendency to biliary reflux.