[Role of perimatrix fibroblasts in development of acquired middle ear cholesteatoma. A hypothesis]

The Relationship between the M1/M2 Macrophage Polarization and the Degree of Ossicular Erosion in Human Acquired Cholesteatoma: An Immunohistochemical Study

The differential involvement of the macrophage activation phenotypes (M1 vs. M2) has been linked to disease severity in various chronic inflammatory disorders. Pharmacologic manipulation of the M1/M2 macrophage polarization has shown therapeutic potential. Cholesteatoma is a destructive chronic middle ear disease with potentially life-threatening complications. The distribution of macrophage polarization phenotypes in middle ear cholesteatoma has not been described. In the present study, human cholesteatoma specimens acquired during tympanomastoidectomy were retrospectively retrieved and immunohistochemically characterized using a combination of antibodies labeling M1 macrophages (CD80), M2 macrophages (CD163), and total macrophages (CD68). The correlations between the immunohistochemical findings and clinical presentation were assessed. The findings revealed that cholesteatomas with more extensive ossicular erosion demonstrated a significantly higher number of M1 (CD80+) cells and a higher M1/M2 ratio than less invasive cholesteatomas (Wilcoxon test, p < 0.05). The extent of ossicular erosion correlated significantly with the M1/M2 ratio (Spearman correlation coefficient ρ = 0.4, p < 0.05). Thus, the degree of ossicular erosion in human acquired cholesteatoma appears to be related to the M1/M2 macrophage polarization. The investigation of macrophage polarization and functions in various clinical presentations of middle ear cholesteatoma is of great interest since it may contribute to the development of pharmaceutical treatment approaches.

Complex Evaluation of Tissue Factors in Pediatric Cholesteatoma

The aim of this study was to describe the appearance and distribution of tissue remodeling markers (MMP-2, MMP-9, TIMP-2, TIMP-4), Sonic hedgehog gene protein (Shh), pro- and anti-inflammatory cytokines (IL–1, IL–10), transcription factor (NF-κβ), proliferation marker (Ki–67), angiogenetic factor (VEGF), tissue defensins (HβD–2, HβD–4) of the pediatric cholesteatoma. Sixteen cholesteatoma samples were obtained from children, eleven skin controls from cadavers. Tissues were stained for MMP-2, MMP-9, TIMP-2, TIMP-4, Shh, IL–1, IL–10, NF-κβ, Ki–67, VEGF, HβD–2, HβD–4. Non-parametric statistic, Mann–Whitney, and Spearman’s coefficient was used. A statistically significant difference was seen between Shh and HβD–2 in perimatrix and control connective tissue, between NF-κβ in cholesteatoma and control skin, and between HβD–4 in matrix and skin epithelium. Complex intercorrelations between MMPs, NF-κβ and VEGF cause the intensification of angiogenesis in cholesteatoma. The persistent increase in Shh gene protein expression in cholesteatoma perimatrix suggests the stimulation of the cholesteatoma growth in children. Similar expression of IL-1 and IL-10 and their intercorrelation, proves there is a balance between pro- and anti-inflammatory cytokines. NF-κβ, and not Ki-67, seems to be the main inducer of cellular proliferation. The main antimicrobial protection is provided by HβD-2.

Pattern of cholesteatomas under a scanning electron microscope - a risk factor for bone resorption

Objective

The damaging effect of cholesteatomas presents mainly as bone resorption by osteoclasts located in the space between the bone and perimatrix. This process is initiated by the molecular cascade of osteoclast differentiation factors. The aim of the study is to analyse cholesteatoma microstructures via scanning electron microscope (SEM), and associate them with risk and grade of bone erosion.

Methods

Pathological middle ear tissue fragments with cholesteatoma visible under a microscope were collected from 58 patients operated on for chronic otitis media with features of bone defects in the middle ear walls. These fragments were examined under a scanning electron microscope.

Results

Analysis of the cholesteatomas' surface under a SEM revealed both regular and irregular structure of the matrix, most being the latter. Irregular matrix structures were observed in cases with a short disease history and in patients for whom this was the first surgical procedure. In our analysis, a cholesteatoma matrix with regular structures was associated with less bone destruction of the middle ear space.

Conclusions

The microstructure of cholesteatomas that showed regular layers under SEM coincides with reduced destruction of the middle ear bone walls. An irregular structure (pathognomonic for a process with a short medical history, and in patients operated on for the first time) is characterised by a tendency towards deeper destruction of bone tissue.

Hystology findings' correlation between the ossicular chain in the transoperative and cholesteatomas

Chronic otitis media is hystopathologycaly defined as the presence of irreversible inflammatory tissue changes in the middle ear. Ossicular lesions represent the most prevalent change.

AIM

to correlate the degree of ossicular chain changes seen during surgery with the inflammatory histological degree and the thickness of the cholesteatoma perimatrix.

STUDY DESIGN

Cross-sectional study.

METHODS

Seventy-one descriptions of surgeries done in patients submitted to tympanomastoydectomy were reviewed. Cholesteatoma were collected and fixed in 10% formaldehyde. Two slides were made for each cholesteatoma, one stained with HE and another with picrossirius. Images were obtained from light microscopy and digitally processed and "blindly" analyzed using Image Pro-Plus Software. For statistical analysis we used Spearman's coefficient. Differences were considered statistically significant if P< or =0.05.

RESULTS

the ossicular chain was involved in 65 cases. The incus was the most frequently affected bone, followed by the stapes and the malleus. When the Spearman's coefficient was employed considering ossicular chain change degree with patient's age by the time of surgery, perimatrix thickness and histological degree of inflammation, correlations were not established.

CONCLUSION

Our findings indicate that ossicular chain changes are practically universal when a cholesteatoma is present. We didn't find correlations related with bone erosion and cholesteatoma's histological findings.

Correlation of cholesteatomas perimatrix thickness with patient's age

Cholesteatoma may occur either in children as in adults; in children, however, they have a more aggressive and extensive growth.

Objective

To compare the thickness of the perimatrix, in μm, between adults (> 18 years old) and children cholesteatomas.

Study design

transversal cohort.

Material and Method

74 cholesteatomas (35 of children) obtained from othologic surgeries were included, fixed in formol 10%. It was made laminas with HE and Picrossisius, with were studied at the optic microscope. We obtained digital images of the laminas at the Image Pro-Plus and we used Spearman's coefficient for data analysis. Differences were considered statistically significant if P.

Association between human beta defensin expression and cholesteatoma formation

OBJECTIVE

To investigate an association between human beta defensin (hBD) expression and cholesteatoma formation.

METHODS

hBD-2 mRNA expressions were assessed in healthy external acoustic meatus skin organ cultures before and after stimulation with Pseudomonas aeruginosa. In addition, hBD-1 and hBD-2 protein production of stimulated and non-stimulated external acoustic meatus skin was visualized by immunohistochemistry. Furthermore, hBD-1 and hBD-2 mRNA expression was analyzed in 25 external acoustic meatus skin, 29 cholesteatoma, and 18 non-cholesteatoma control samples. Non-stimulated meatal tissue preparation did not express hBD-2, whereas incubation with P. aeruginosa demonstrated hBD-2 induction.

RESULTS

The hBD-1 mRNA expression was detected in cholesteatoma (14/17), meatal skin, and middle ear mucosa (11/18). hBD-2 mRNA expression was shown in eight cholesteatoma (28.5%) and in three middle ear mucosa tissue samples (37.5%).

CONCLUSION

Our data suggest constitutional hBD-1 and inducible hBD-2 expression in chronic middle ear infection and cholesteatoma. Failure of hBD-1 and hBD-2 expression might dispose to exacerbation of cholesteatoma disease. The organ culture model of the external acoustic meatus skin is effective in order to evaluate germ stimulation experiments.

Photodynamic effect of argon and diode laser on cholesteatoma cell cultures after intravital staining with absorption enhancers

Chronic epitympanic otitis media, or chronic suppurative osteitis, is a destructive form of chronic middle-ear inflammation. The therapy of choice is complete surgical removal of the squamous epithelium from the middle ear. It is often impossible to inspect all areas of the middle ear with the posterior canal wall intact. Not all recesses can be reliably monitored with the microscope, particularly in the area of the antrum and hypotympanum. Residual squamous epithelium here causes frequent recurrences following cholesteatoma surgery. This study examines the effect of argon and diode lasers on cholesteatoma tissue. The aim is to develop a laser treatment selectively directed against cholesteatoma cells that can be performed after cholesteatoma surgery to eliminate any residual squamous epithelium. Intraoperatively harvested monolayer-cultured cholesteatoma cells stained in vivo with various absorption enhancers served as the in vitro examination model. Argon (499 nm) and diode lasers (810 nm) were applied since their irradiation has an appropriate tissue penetration depth and is absorbed by various chromophores such as neutral red (475-500 nm), fluorescein (488 nm), and indocyanine green (790-810). Intracellular staining of cultured cells increased the optical density at the wavelength corresponding to the dye. Neutral red damaged 50-60% of cultured cells merely by intracellular accumulation at high concentrations. An additive cell destruction of about 30% was achieved by also applying argon laser irradiation. Fluorescein diacetate caused no appreciable stain-induced damage to cultured cholesteatoma cells. Argon laser irradiation destroyed up to 60% of the cultures. Indocyanine green resulted in only minor damage to cultured cells. The diode laser destroyed up to 60% of the irradiated cells. Selective staining of cholesteatoma cells was not achieved with any of the dyes examined. Thus, other stained tissue could be damaged. Staining and subsequent laser irradiation destroys up to 60% of cultured cholesteatoma cells. Unstained irradiated cells are not affected. Indocyanine green and fluorescein are nontoxic and may thus be used as absorption enhancers. The diode and argon lasers appear to be basically suitable. Cell staining is not selective, i.e., other tissues would also be stained and damaged. To avoid such unwanted damage, it would be desirable to couple the chromophore to a specific antibody that binds only to cholesteatoma cells.

Knowledge about cholesteatoma, from the first description to the modern histopathology

OBJECTIVE

The aim of this study was to understand the historical development of the knowledge of cholesteatoma.

MATERIALS AND METHODS

Review of the literature from 1683 to 1999 concerning the date-related knowledge of cholesteatoma.

RESULTS

In 1683, Duverney first described a temporal bone tumor probably corresponding to a cholesteatoma. Until 1838, when Müller coined the term cholesteatoma, nothing new about this condition appeared in medical publications. After 1838, three main theories about the pathogenesis of cholesteatoma were published. Virchow, in 1855, considered cholesteatoma to be a tumor arising from the metaplasia of mesenchymal cells to epidermal cells, growing then as tumoral cells. Gruber, Wendt, and von Troeltsch, in 1868, considered cholesteatoma to be the result of a metaplasia not of bone cells but of tympanic mucosa cells into a malpighian epithelium. Politzer, in 1869, assumed that cholesteatoma was a glandular neoplasm of middle ear mucosa. Bezold and Habermann, in 1889, considered cholesteatoma to be the result of migration of the external ear canal epidermis into the tympanic cavity via a marginal perforation after acute or chronic otitis. It took 40 years of discussions about these three theories to finally confirm that Habermann and Bezold were correct.

CONCLUSION

The knowledge of cholesteatoma has evolved with other medical branches. As otologists began to monitor their patients in vivo, not limiting their observations to temporal bone dissections, the genesis of cholesteatoma became well understood. Today, with immunology and new histopathologic techniques, it is anticipated that we will learn much more about cholesteatoma.