Bengt Carlsöö

Recurrent primary pleomorphic adenomas of salivary gland origin

The rate of tumor recurrence after surgery for benign salivary gland pleomorphic adenoma varies considerably in different clinical settings and seems to depend to a great extent on the surgical technique used. The importance of tumor spillage for subsequent recurrence has recently been questioned. The current follow‐up study was undertaken to ascertain whether intrasurgical rupture, tumor spillage, or any histopathologic feature might have had an impact on the rate of recurrence.

Experimentally induced polyps in the sinus mucosa : a structural analysis of the initial stages

To document polyp formation in the sinus mucosa, the authors of this study subjected New Zealand white rabbits to different modes of manipulation intended to induce inflammation of the maxillary sinus. These manipulations included a combination of bacterial infection and mechanical trauma, the deposition of agarose into the sinus cavity, and the deposition of N‐formyl‐methionyl‐leucyl‐phenylalanine, a chemotactic peptide, into the sinus cavity. A majority of animals developed polyps, which were examined by light and electron microscopy.

Regeneration of Maxillary Sinus Mucosa following Surgical Removal Experimental Study in Rabbits

A rapid regeneration of the epithelium takes place in the maxillary sinus in rabbits after experimental operative removal of the mucosa. Two weeks postoperatively the previously denuded areas have reepithelialized. The subepithelial glands, however, do not seem to regenerate. The normal sinus mucosa contains numerous serous glands in the lamina propria, but in the regenerated mucosa these glands are replaced by dense connective tissue. Atypical glands and polyp formations are sometimes encountered, but goblet cells are sparse. Furthermore, the sinus cavity on the operated side is reduced in size compared with the nonoperated side because of fibrosis and periosteal reactions including bone degradation and neogenesis. This study indicates that although the mucosa is reepithelialized within 2 weeks, the regeneration of the lamina propria is incomplete, and reactive cellular processes such as bone remodeling, fibroblast proliferation, and formation of polyps and “atypical glands” are characteristic of regenerating mucosa.

Histopathological observations in chronic maxillary sinusitis

Biopsy samples from the maxillary sinus mucosa of patients with purulent, non-purulent and recurrent sinusitis were studied histologically and compared with those from a maxillary sinus of patients with no previous history of sinus disease on the side of sampling. Basement membrane thickening, atypical gland formation, goblet cell hyperplasia, mononuclear inflammatory cell infiltration and subepithelial oedema were observed in all groups irrespective of the appearance of the effusion. Although the inflammatory variables in selected areas of the mucosa seemed to show an increase in severity with the increasingly severe forms of sinusitis, neither the endoscopic mucosal appearance nor the nature of the sinus effusion corresponded to any specific histological pattern.

Experimental Acute Sinusitis in Rabbits: A Bacteriological and Histological Study

A bacteriological and histological study of experimentally induced acute pneumococcal sinusitis was performed in 69 New Zealand White rabbits. The sinus ostium was blocked on one side on the first day of the experiment. On the second day, 10(7)-10(9) Streptococcus pneumoniae in 1 ml were injected into the same sinus cavity. Purulent sinusitis developed unilaterally in all rabbits. Histological examination of the sinus mucosa revealed edema, dilated venules, leukocytic infiltration of the mucosa as well as localized epithelial lesions. On staining with acridine orange at pH 4.0, the bacteria were observed in the secretion but not in the mucosa. When we used Streptococcus pneumoniae subjected to an animal passage, the bacteria were re-isolated in 9/10 infected sinuses. Neither sole occlusion of the ostium nor injection of pneumococci into a sinus cavity with a patent ostium resulted in a bacterial sinusitis. Obstruction of the sinus ostium and the use of a virulent Streptococcus pneumoniae strain were essential for the induction of sinusitis in rabbits.

Experimental maxillary sinusitis induced by Bacteroides fragilis. A bacteriological and histological study in rabbits.

Experimental anaerobic maxillary sinusitis was induced in New Zealand White rabbits by blocking the ostium and inoculating Bacteroides fragilis, strain NCTC 9343. The animals were examined histologically and bacteriologically after 5 days, and 2, 3 and 4 weeks. All the infected sinuses displayed signs of moderate or severe inflammation throughout the study period. Ciliary damage and desquamation, hyperplasia and metaplasia of the epithelium were characteristic features. Furthermore, heavy leukocyte- and, particularly, round cell-infiltration, fibrosis, periosteal hyperplasia and bone degradation and -formation were also frequently encountered. The secretory cell count in the epithelium increased, including the regeneration of goblet cells. After 4 weeks no obvious recovery could be seen, and the inducing microorganism was re-isolated in the majority of cases. In comparison with experimental pneumococcal sinusitis, the B. fragilis infection exerts a more prolonged and severe inflammation.

Formation of Mucosal Polyps in the Nasal and Maxillary Sinus Cavities by Infection

Unilateral maxillary sinusitis was experimentally induced in New Zealand White rabbits with Streptococcus pneumoniae serotype 3, Bacteroides fragilis NCTC 9343, and Staphylococcus aureus V8. In another group of rabbits, sinusitis was induced by blocking of the sinus ostium only. Bacteriologic and light microscopic analysis was performed after 5 days to 1 month. Granulation-like polyps developed after deep mucosal inflammatory trauma initiating fibroblast proliferation, angiogenesis, and epithetlial migration to cover the polyp. In regions of a more superficial trauma—characterized by epithetlial desquamation and fibroblast growth—proliferation and differentiation of basal cells resulted in the formation of microcavities dissecting off edematous polyps. Polyps could be found in all sinusitis groups, irrespective of inducing agent. The cellular events of polyp formation appear to be the result of a continuous inflammatory reaction and are not directly related to the presence of a certain microorganism. Instead, the potential of any microorganism to induce a deep mucosal trauma or epithelial desquamation seems essential for its ability to initiate polyp formation. (OTOLARYNGOL HEAD NECK SURG 1993;109:522-9.)

HISTOLOGIC EVALUATION OF TEFLON GRANULOMAS OF HUMAN VOCAL CORDS A Light and Electron Microscopic Study

It is sometimes necessary to remove Teflon from convex vocal cords to improve the quality of voice. This has provided material which shows the histologic effect of Teflon injection in the vocal cord at intervals varying from four weeks to sixteen years after injection. In the study, vocal cord specimens were obtained from twelve patients. These were all examined with light microscopy and some observations have also been made with electron microscopy.

Mucosal Pathology of the Nose and Sinuses: A Study in Experimental Maxillary Sinusitis in Rabbits Induced by Streptococcus Pneumoniae, Bacteroides Fragilis, and Staphylococcus Aureus

Unilateral maxillary sinusitis was experimentally induced in New Zealand White rabbits with Streptococcus pneumoniae serotype 3, Bacteroides fragilis NCTC 9343, and Staphylococcus aureus V8 in order to study possible differences in the inflammatory response of the sinus and nasal mucosa at different time-intervals during a 12-week period of infection. The initial sinus mucosal response, most pronounced in pneumococcal sinusitis, was characterized by leukocytosis, epithelial desquamation, and squamous cell metaplasia. Tissue reactions at later intervals included fibrosis of lamina propria, gland involution, polyp formation, and bone remodelling, and were most pronounced in S. aureus and B. fragilis sinusitis. The nasal mucosa was altered with a redistribution of goblet cells, development of polyps in the ethmoidal region, involution of Bowmans glands and locally, areas of degenerated olfactory sensory epithelium. These findings endorse that the degree of local pathology depends on the infecting microorganisms specific pathogenetic factors. However, local tissue factors guiding the cellular inflammatory proliferative and regenerative processes are also of fundamental importance for the type of pathological changes occurring in an infected nasal or sinus mucosa.

Mucosal Fine Structure in Experimental Sinusitis

Rabbit maxillary sinuses were inoculated with Streptococcus pneumoniae and Bacteroides fragilis, and the histologic response in the sinus mucosa was observed over a 12-week period. An increased height of the cylindric cells and hyperplasia of the basal cells were frequent findings irrespective of the pathogen inoculated. The disease was found to influence the character of the secretory product from epithelial secretory cells and to degranulate the subepithelial glands. Ciliary loss was a transitional finding. A reduction in the number of mitochondria, the occurrence of deformed short microvilli, and cytoplasmic blebbing were seen in the cells devoid of normal cilia. It is inferred from this study that pneumococcal sinusitis in rabbits is a self-limiting process, and the mucosal sequelae of the acute infection are persisting goblet cells, slight focal fibrosis, and edema. Inoculation with B fragilis produces a chronic inflammatory process, with infiltration of mononuclear cells, luminal dilatation of the glands exhibiting zymogen granule depletion, and an increased thickness of the whole mucosal layer.