Histological and immunohistochemical study of pars tensa retraction pocket

Cartilage tympanoplasty for retraction pocket of the tympanic membrane in children

Background

Retraction pocket (RP) of the tympanic membrane (TM) is a common pathology in children that can cause ossicular chain erosion, cholesteatoma formation, and potentially life-threatening complications of cholesteatoma. This study assessed the functional and anatomical results of cartilage grafting in children with severe RP of the TM.

Methods

This was a retrospective review of 212 children from a tertiary referral center.

Results

We identified significant differences in hearing results, indication criteria, and location of TM fixation between stages II and III of RP (according to Charachon). We observed a significantly higher incidence of RP in boys than in girls.

Conclusions

Cartilage tympanoplasty for retraction pocket of the tympanic membrane in children is a safe procedure with good anatomical and hearing results.

Evaluation of Recurrence and Hearing Outcome for Inactive Squamosal Disease after Cartilage Strengthening Tympanoplasty

Introduction  Inactive squamosal disease is unique for having a conflicting treatment protocol, with an age-old debate between early surgical intervention or keeping patients in a long-term follow-up. The shifting paradigm is early intervention to prevent further progress into active disease and improve hearing outcome in its nascent stage.

Objective  To evaluate recurrence and hearing outcome in cases of inactive squamosal disease after cartilage strengthening tympanoplasty.

Methods  The study was conducted on 50 patients with inactive squamosal disease. Detailed examination was done to grade the retraction. All patients underwent autologous conchal cartilage tympanomastoidectomy with temporalis fascia grafting. Recurrence and hearing evaluations were done by pure tone audiogram at regular intervals for one year.

Results  Hearing loss was the most common presenting symptom. Isolated pars tensa retractions were more common (54%) than pars flaccida (12%), or those involving both (34%). Ossicular status was normal in only 14% of the cases, and the most common ossicular damage was to the lenticular process of the incus (52%). Three of the patients (6%) had residual perforation at the 3 ^rd month of follow-up. Subjective improvement in hearing was reported by 42% patients. Hearing improvement greater than 10 dB was found in 24 patients (48%). Air–bone gap reduced from 25.16 ± 8.15 dB preoperatively to 12.90 ± 6.20 at 1 year of follow-up. Recurrence was seen in three patients (6%).

Conclusion  Early intervention by cartilage strengthening of weakened tympanic membrane and ossicular reconstruction not only offers better hearing results, but also prevents progress to active disease.

Pathogenesis of Retraction Pocket of the Tympanic Membrane-A Narrative Review

Several theories describe the development of the retraction pocket of the tympanic membrane (RP). Many authors suggest that the negative middle ear pressure is the main reason responsible for developing this condition. A narrative review has been undertaken, and conclusions are drawn reflecting a current knowledge with our new observations in the histological and immunohistochemical study. Recent studies show the important role of inflammation in the development and progression of RP. A review of the available literature shows that the inflammation plays a key role in pathogenesis of the RP and its progression to the cholesteatoma. We support this statement with our new results from histological and immunohistochemical analysis of the RPs.

Immunohistochemical analysis of retraction pocket pars tensa of tympanic membrane in children

AIMS

Immunohistochemical analysis of retraction pocket pars tensa of tympanic membrane in children. Identification of signs typical for cholesteatoma and support of retraction theory of cholesteatoma.

STUDY DESIGN

a prospective study analysing 31 surgically removed retraction pockets.

DEPARTMENT

University Hospital, Children's Medical Centre Methods: Retraction pockets processed by a standard process for immunohistochemical analysis. The observed findings were specified using antibodies CD45 LCA (leukocyte common antigen), CD31 (platelet endothelial cell adhesion molecule), D2-40 (marker of lymphatic endothelium), MMP9 (marker of degradation of connective tissue extracellular matrix) and Ki67 (cellular marker of proliferation).

RESULTS

All observed parameters except for MMP9 had a significantly higher incidence in retraction pocket stage III compared to stage II according to Charachon.

CONCLUSION

We described immunohistochemical signs of retraction pocket pars tensa of tympanic membrane in children resulting in cholesteatoma. All the observed signs occur in the structure of matrix and perimatrix of cholesteatoma. A significantly higher incidence of all observed parameters except from MMP9 was proved in retraction pocket stage III, unlike in stage II. This observation proves the fact that retraction pocket is a progressive disease and is a procholesteatoma stage.

Histological analysis of retraction pocket pars tensa of tympanic membrane in children

AIMS

Histological and histochemical analysis of retraction pocket of pars tensa of tympanic membrane in children. Identification of morphological abnormalities in comparison with a healthy tympanic membrane as it is described in standard textbook. Identification of signs typical for cholesteatoma and support for a retraction theory of cholesteatoma formation.

STUDY DESIGN

A prospective study analysing 31 samples of retraction pockets taken during surgery.

DEPARTMENTS

University Hospital, Children's Medical Centre

METHODS

Samples of retraction pockets were processed by a standard process for light microscopy, stained by haematoxylin-eosin. Van Gieson's stain was used for differential staining of collagen, Verhoeff's stain for elastic fibre tissues, Alcian blue for acidic polysaccharides and PAS (Periodic Acid Schiff) method for basement membrane polysaccharides.

RESULTS

The following findings were observed in the samples of retraction pockets: hyperkeratosis (100%), hypervascularisations (100%), subepithelial fragmented elastic fibres (96%), myxoid changes (87%), subepithelial inflammatory infiltration (84%), rete pegs (71%), papilomatosis (71%), intraepithelial inflammatory cellularizations, (48%), intraepithelial spongiosis (16%) and parakeratosis (3%). No basement membrane continuity interruptions were observed. Thickness of retraction pocket, thickness of epidermis, occurrence of rete pegs and frequency of fragmented elastic fibres was higher in a Grade III stage RP than Grade II stage RP (according to Charachon).

CONCLUSION

Morphological abnormalities in the structure of retraction pockets in comparison with a healthy tympanic membrane were described. The changes are typical for a structure of cholesteatoma (these changes are common in matrix and perimatrix), supporting retraction theory of its origin. Our observations show that it is inflammation that probably plays a key role in the pathogenesis of retraction pocket. The frequency of some of the changes increases with the stage of retraction pocket (II-III according to Charachon). Basement membrane continuity interruptions are not typical for retraction pockets.

Large-scale proteomics differentiates cholesteatoma from surrounding tissues and identifies novel proteins related to the pathogenesis

Cholesteatoma is the growth of keratinizing squamous epithelium in the middle ear. It is associated with severe complications and has a poorly understood etiopathogenesis. Here, we present the results from extensive bioinformatics analyses of the first large-scale proteomic investigation of cholesteatoma. The purpose of this study was to take an unbiased approach to identifying alterations in protein expression and in biological processes, in order to explain the characteristic phenotype of this skin-derived tumor. Five different human tissue types (cholesteatoma, neck of cholesteatoma, tympanic membrane, external auditory canal skin, and middle ear mucosa) were analyzed. More than 2,400 unique proteins were identified using nanoLC-MS/MS based proteomics (data deposited to the ProteomeXchange), and 295 proteins were found to be differentially regulated in cholesteatoma. Validation analyses were performed by SRM mass spectrometry. Proteins found to be up- or down-regulated in cholesteatoma were analyzed using Ingenuity Pathway Analysis and clustered into functional groups, for which activation state and associations to disease processes were predicted. Cholesteatoma contained high levels of pro-inflammatory S100 proteins, such as S100A7A and S100A7. Several proteases, such as ELANE, were up-regulated, whereas extracellular matrix proteins, such as COL18A1 and NID2, were under-represented. This may lead to alterations in integrity and differentiation of the tissue (as suggested by the up-regulation of KRT4 in the cholesteatoma). The presented data on the differential protein composition in cholesteatoma corroborate previous studies, highlight novel protein functionalities involved in the pathogenesis, and identify new areas for targeted research that hold therapeutic potential for the disease.

Identification of novel cholesteatoma-related gene expression signatures using full-genome microarrays

Background

Cholesteatoma is a gradually expanding destructive epithelial lesion within the middle ear. It can cause extensive local tissue destruction in the temporal bone and can initially lead to the development of conductive hearing loss via ossicular erosion. As the disease progresses, sensorineural hearing loss, vertigo or facial palsy may occur. Cholesteatoma may promote the spread of infection through the tegmen of the middle ear and cause meningitis or intracranial infections with abscess formation. It must, therefore, be considered as a potentially life-threatening middle ear disease.

Methods and Findings

In this study, we investigated differentially expressed genes in human cholesteatomas in comparison to regular auditory canal skin using Whole Human Genome Microarrays containing 19,596 human genes. In addition to already described up-regulated mRNAs in cholesteatoma, such as MMP9, DEFB2 and KRT19, we identified 3558 new cholesteatoma-related transcripts. 811 genes appear to be significantly differentially up-regulated in cholesteatoma. 334 genes were down-regulated more than 2-fold. Significantly regulated genes with protein metabolism activity include matrix metalloproteinases as well as PI3, SERPINB3 and SERPINB4. Genes like SPP1, KRT6B, PRPH, SPRR1B and LAMC2 are known as genes with cell growth and/or maintenance activity. Transport activity genes and signal transduction genes are LCN2, GJB2 and CEACAM6. Three cell communication genes were identified; one CDH19 and two from the S100 family.

Conclusions

This study demonstrates that the expression profile of cholesteatoma is similar to a metastatic tumour and chronically inflamed tissue. Based on the investigated profiles we present novel protein-protein interaction and signal transduction networks, which include cholesteatoma-regulated transcripts and may be of great value for drug targeting and therapy development.