Pathogenesis of Cholesteatoma

Temporal bone CT-based anatomical parameters associated with the development of cholesteatoma

BACKGROUND

Cholesteatoma is caused by disorders of the middle ear ventilation that trigger a progressive series of events responsible for its formation. The aim of this study was to identify possible radiological CT-derived parameters predisposing to ventilation disorders and cholesteatoma.

METHODS

In this retrospective study, patients diagnosed with cholesteatomatous chronic otitis media who underwent temporal bone CT and open tympanoplasty surgery have been included, as well as control patients with clinical examination negative for organic otological pathology who underwent temporal bone CT for other reasons. For each patient, the following parameters have been extracted from CT volumes: degree of mastoid pneumatization, prominence of the cog, patency of the Eustachian tube, antrum width, aditus width, anterior and posterior epitympanic widths, and epitympanic height.

RESULTS

Sixty patients have been included, thirty of whom belonged to the group of patients with cholesteatoma and the remaining part to the group of patients without organic otological pathology. The prevalence of a low degree of mastoid pneumatization was significantly higher among patients with cholesteatoma, as well as for the prevalence of cog prominence (p < 0.001). All the continuous variables were found to have statistical significance (p < 0.05) in the comparison between groups except for the width of the antrum.

CONCLUSION

Mastoid pneumatization degree, prominence of the cog and epitympanic measures based on temporal bone CT could be good radiological correlates of the ventilatory capabilities of the epitympanum which, if compromised, can facilitate the development of cholesteatoma.

Keratinocyte growth factor signaling promotes stem/progenitor cell proliferation under p63 expression during middle ear cholesteatoma formation

PURPOSE OF REVIEW

Middle ear cholesteatoma is an epithelial lesion that expands into the middle ear, resulting in bone destruction. However, the pathogenesis of this has been unknown. The purpose of this review is to understand the role of keratinocyte growth factor (KGF) during epithelial stem and/or progenitor cell proliferation in middle ear cholesteatoma.

RECENT FINDINGS

Many researchers have investigated the molecular mechanism of middle ear cholesteatoma to establish a conservative treatment. Recently, some studies have focused on the stem cells of middle ear cholesteatoma and their detection, but the key molecules for stem cell formation were not shown.

SUMMARY

We established an animal model for middle ear cholesteatoma and are showing the results of our studies. KGF expression accelerates the proliferation of stem/progenitor cells through the induction of transcription factor p63 expression in the epithelium of the tympanic membrane and mucosal epithelium overlying the promontory of the cochlea and within the attic. This is typical in middle ear cholesteatoma. Moreover, the partial epithelial-mesenchymal transition under the p63 signaling pathway plays an essential role in epithelial cell growth in middle ear cholesteatoma formation. Understanding p63 expression following KGF expression and associated signaling events can improve therapeutic outcomes in patients with middle ear cholesteatoma.

Partial Epithelial-Mesenchymal Transition Was Observed Under p63 Expression in Acquired Middle Ear Cholesteatoma and Congenital Cholesteatoma

INTRODUCTION

Partial epithelial-mesenchymal transition (p-EMT) is a process by which epithelial cells partially lose their intercellular adhesion and change to obtain migration ability. The transcription factor p63 regulates the expression of cadherin family and induces epithelial cell proliferation. In this study, we hypothesized that p-EMT under p63 expression may be a key factor in epithelial cell growth in middle ear cholesteatoma.

METHODS

Specimens were surgically excised from patients with congenital cholesteatoma (CC) (n = 48), acquired middle ear cholesteatoma (AC) (n = 120), and normal skin tissue (n = 34). We analyzed immunohistochemically for the EMT marker (N-cadherin), adherence junction marker (E-cadherin), and tight junction marker (claudin-1, claudin-4, occludin). We also examined the labeling index (LI) of p63 and Proliferating cell nuclear antigen (PCNA) (late S phase marker), and Snail expression as a mobility marker.

RESULTS

The expression of p63 (CC 51.0 ± 7.4%, AC 50.0 ± 5.9%) was significantly higher in the thickened epithelium of CC and AC compared with normal skin tissue (p < 0.0001). The loss of E-cadherin was observed (CC 50.0%, AC 55.8%) but the expression patterns in the tight junction were almost normal. N-cadherin was partially detected in the basal and upper layer of epithelium in CC and AC. In contrast to that of normal skin tissue, the LI of PCNA was significantly higher in AC (p < 0.0001). The positive rate of Snail was significantly higher in CC (p < 0.0001).

CONCLUSION

This study indicates that p-EMT via the p63 signaling pathway might plays an essential role in epithelial growth in AC and CC formation, although tight junction formation and terminal differentiation were not affected in those processes.

Pediatric tympanic membrane cholesteatoma: Systematic review and meta-analysis

INTRODUCTION

Tympanic membrane cholesteatoma (TMC) is a rare anomaly found in pediatric patients with no significant otologic history. Its pathogenesis appears distinct from congenital mesotympanic cholesteatoma. This systematic review and meta-analysis evaluates the management of TMC.

METHODS

Two authors independently conducted a systematic review using the PubMed-NCBI, Cochrane Library, and Web of Science databases. Studies describing cases of pediatric TMC were included. Patients with history of chronic otitis, otorrhea, trauma, or otologic surgery were excluded.

RESULTS

Seventeen articles were included for a total of 45 patients. Mean age was 35.9 months with 56% female. Patients aged ≥36 months had significantly larger cholesteatomas than younger patients (4.2 vs 1.9 mm, p = 0.004). Nine patients (20%) had middle ear extension but none had middle ear or ossicular disease. CT scans influenced management in 1 of 26 patients. All patients were managed surgically by transcanal approach (93%) or retroauricular approach (7%). Surgery involved enucleation without TM perforation (80%) or complete excision with TM grafting (20%). In 23 patients, the fibrous TM remained intact, and there were no recurrences in this group at a mean follow-up of 11 months. Overall, there was 1 recurrence (2%), eventually requiring reoperation. No patients experienced persistent tympanic membrane perforation, chronic otitis, or hearing loss.

CONCLUSION

TMC occurs in pediatric patients without an otologic history. Associated middle ear involvement has not been reported. CT scanning may not be necessary for work up and management of this disorder. A transcanal approach with enucleation is often sufficient treatment. Risk of recurrence appears lower than with congenital mesotympanic cholesteatoma.

Mastoid cholesteatoma: a result of metaplasia

Presence of cholesteatoma in the middle ear of the patients with chronic mucosal otitis media has been reported in the literature. But presence of cholesteatoma only in the mastoid, in the absence of cholesteatoma in the middle ear of a patient with chronic mucosal otitis media, is not reported in the literature. In this article three cases of mastoid cholesteatoma, in patients with a clinical picture of chronic mucosal otitis media is reported along with the literature review.

Expression of keratinocyte growth factor (KGF) and its receptor in a middle-ear cavity problem

OBJECTIVES

To investigate the pathogenesis of one of the most troublesome conditions following ear surgery, a middle-ear cavity problem.

METHODS

Keratinocyte growth factor (KGF) and its receptor (KGFR), the ratio of proliferating epithelial cells using Ki-67, and the extent of infiltration of B cells and T cells were examined immunohistochemically in 10 ears with a cavity problem, 70 ears with cholesteatoma and 8 ears with normal skin at the retroauricular incision.

RESULTS

KGF was positive in 40% of cavity problem specimens, 37.5% of normal skin specimens, and was positive in 88% of cholesteatoma specimens (cavity problem vs. cholesteatoma, p=0.0004). The positive rate of KGFR in the cavity problem group (33.3%) was between those in cholesteatoma (60%) and normal skin (0%). In contrast to the cholesteatoma specimens, a significantly smaller number of Ki-67 labeling index (LI) was detected in the cavity problem specimens. B cell LI was significantly higher but T cell LI was significantly lower in the cavity problem specimens than in the cholesteatoma group.

CONCLUSIONS

Our present study indicated that the discordance of paracrine action between stromal KGF and epithelial KGFR with a large number of infiltrating B cells may play an important role in the pathogenesis of a cavity problem.

Algumas considerações sobre colesteatomas adquiridos pediátricos e adultos

Neste artigo, os autores dissertam sobre o tema colesteatoma, desde a primeira vez em que foi utilizada a palavra por Mueller (1838), até informações atuais. Fazem uma abordagem de sua definição, passam pela etiopatogênese e apresentam noções básicas sobre sua biologia. Ainda realizam uma ampla revisão sobre colesteatoma pediátrico, apresentam dados clínicos epidemiológicos e biológicos e mostram um paralelo com o colesteatoma em adultos. Para finalizar, descrevem alguns trabalhos sobre erosão da cadeia ossicular correlacionando-a com dados sobre a perimatriz, colágeno e colagenase.

Some considerations about acquired adult and pediatric cholesteatomas

Authors debate about cholesteatomas, from the first time this word was employed, by Muller, in 1838, until the recent updates. They dissert about its definition, etiology and pathology and present basic concepts about its biology. They also make a wide review about pediatric cholesteatoma, its epidemiology and biology, and compare it with adult cholesteatoma. Finally, they describe some articles about ossicle chain erosion and its correlation with cholesteatoma perimatrix, collagen and collagenase.

Eustachian tube patency and function in tympanoplasty with cartilage palisades or fascia after cholesteatoma surgery

OBJECTIVE

To compare the Eustachian tube patency and function after tympanoplasty with either cartilage palisades or fascia grafting after one-stage surgery in children with tensa cholesteatoma.

STUDY DESIGN

In children operated for tensa cholesteatoma, cartilage palisade tympanoplasty was performed in 32 ears and fascia tympanoplasty in 29 ears. The patency of the Eustachian tube was evaluated by the Valsalva maneuver before the operation, 1 to 3 months after the operation, and at a follow-up examination 46(1/2) months later (median). Eustachian tube function was evaluated by the nine-step inflation/deflation tympanometric test and the Toynbee test at the follow-up examination. Otomicroscopy and hearing evaluation were performed before and after surgery as well as at the follow-up.

MAIN OUTCOME MEASURES

Eustachian tube patency and function. Hearing, postoperative eardrum perforation/retraction, and cholesteatoma recurrence.

RESULTS

The Valsalva maneuver was positive in 30% of the ears before the operation, in 65% primarily after the operation, and in 78% at the follow-up examination. A poor tubal function was found in 57% at follow-up. Overall, the late functional hearing results were better in ears with a positive Valsalva maneuver. There were no differences in tubal patency or function in relation to graft material, cholesteatoma, and tympanoplasty type. In ears with a poor tubal function, the hearing results were significantly better in the palisade group (63% success), compared with the fascia group (17% success). All of the four perforations, most of the retractions, and a single moist eardrum were found in the fascia group at the reevaluation. We found no correlation between the condition of the eardrum and the Eustachian tube function at the last evaluation. However, in ears with a poor tubal function, a nonretracted, nonperforated drum was found with higher frequency in the palisade group. Decision matrix analysis showed that the last postoperative Valsalva maneuver was the best predictor of the drum condition at the reevaluation.

CONCLUSIONS

The Eustachian tube patency frequently improves after tympanoplasty after cholesteatoma surgery in children, regardless of graft material. The patency and function of the Eustachian tube seem to be without relation to graft material, cholesteatoma, or tympanoplasty type. Cartilage palisade tympanoplasty may be a better reconstruction technique after cholesteatoma surgery, especially in ears with a poor tubal function.

Possible involvement of keratinocyte growth factor and its receptor in enhanced epithelial-cell proliferation and acquired recurrence of middle-ear cholesteatoma

Middle-ear cholesteatoma is characterized by enhanced proliferation of epithelial cells and granular tissue formation. However, the molecular mechanism underlying these pathological changes is largely unknown. Keratinocyte growth factor (KGF) is a mesenchymal cell-derived paracrine growth factor that specifically stimulates epithelial cell proliferation. In the present study, we investigated the possible involvement of KGF and its receptor, KGFR, in the pathogenesis of cholesteatoma using in situ hybridization and immunohistochemistry, respectively. We examined 56 cholesteatoma specimens, and 8 normal skin areas as control. KGF and KGFR expression was examined by immunohistochemistry using rabbit anti-human KGF and anti-human KGFR polyclonal antisera raised in our laboratories against synthetic peptides corresponding to parts of human KGF and KGFR, respectively. KGF protein and mRNA were detected exclusively in stromal fibroblasts and infiltrating T lymphocytes in 80% of cholesteatoma cases, whereas KGFR protein and mRNA were localized in the epithelium in 72% of cases. Assessment of the proliferative activity of cholesteatoma using the labeling index for Ki-67 showed a significantly higher Ki-67 labeling index (66%) in KGF+/KGFR+ cases than other cases. There was a significant correlation between KGF+/KGFR+ expression and recurrence. Our results indicate the possible involvement of both KGF and KGFR in enhanced epithelial cell proliferative activity and recurrence of cholesteatoma.

Cholesteatoma in a child with congenital ichthyosiform erythroderma

A 7-year-old girl had non-bullous congenital ichthyosiform erythroderma (NBCIE) in treatment with retinoids. She also suffered continuous desquamation of the external ears, recurrent external otitis, chronic adenoiditis, tubaric dysfunction and intermittent episodes of otitis media and developed a cholesteatoma in her left ear. Chronic scaling disorders, such as NBCIE and other ichthyosis, can be entities at risk for the development of cholesteatoma in childhood.

Silent intratympanic membrane cholesteatoma

OBJECTIVE

To detect the presence of intratympanic membrane cholesteatoma in cases of chronic otitis media.

DESIGN

Two hundred forty-three temporal bones from patients with chronic otitis media were studied for the presence of intratympanic membrane cholesteatoma.

METHODS

Specimens had been previously removed at autopsy, fixed in 10% buffered formalin, decalcified in trichloroacetic acid, dehydrated in a graded series of ethanol, and embedded in celloidin. Sections were cut at a thickness of 20 microm, stained with hematoxylin eosin, and examined using light microscopy.

RESULTS

Intratympanic membrane cholesteatomas were found in five of the 243 temporal bones with chronic otitis media. All temporal bones with intratympanic membrane cholesteatomas were from adult patients. Two patients had bilateral intratympanic cholesteatomas in symmetric quadrants of the tympanic membrane, and the remaining patients with unilateral intratympanic membrane cholesteatoma had been operated on previously for a cholesteatoma of the opposite ear. Other common findings included chronic granulation tissue in the middle ears and mastoids, ossicular pathologic conditions, and in four of the five ears, fluid in the middle ears and/or mastoids.

CONCLUSION

When a white area is observed on the tympanic membrane of patients (especially those with "silent" chronic otitis media), differential diagnosis should include not only tympanosclerosis, but also intratympanic membrane cholesteatoma.

Inhibition of Cholesteatoma Migration in vitro with all-Trans Retinoic Acid

Retinoids have recently become of interest to clinicians because of their ability to inhibit migration and proliferation of premalignant squamous cells while enhancing growth and proliferation of normal cells. An in vitro investigation was undertaken to determine whether retinoic acid exhibits similar inhibitory effects on cholesteatoma cells. Cholesteatoma specimens were obtained intraoperatively from 10 patients undergoing mastoidectomy or revision mastoidectomy for chronic ear disease. Cholesteatoma explant growth and en mass migration were observed daily, and topographic maps were constructed at various time intervals to quantify rate and direction of expiant migration in the presence or absence of all- trans retinoic acid. Before all- trans retinoic acid administration, explants migrated very rapidly (1 to 2 mm/day). A maximum threefold inhibition of migratory rate occurred, with explants exposed to 0.1 μmol/L retinoic acid when compared with controls. A sixfold maximum inhibition was observed at higher retinoic acid concentrations (5 μmol/L). On removal of all- trans retinoic acid, twofold and fourfold increases in migratory rates were observed. The direction of explant migration varied significantly for long periods of time and appeared not to be affected by retinoic acid. This investigation suggests that all- trans retinoic acid has an inhibitory effect on cholesteatoma cell migration. Retinoids may have a role in controlling cholesteatoma disease in the future.

Human-papillomavirus DNA in cholesteatomas

Cholesteatoma of the middle ear is a relatively common disorder, often with severe consequences. Histologically, the aggressively growing, bone-destructing form shows papillary growth and koilocytosis, which are characteristic of papillomavirus-induced lesions. A PCR (polymerase chain reaction) method using degenerate primers for the detection of any known or as yet unknown HPV (human papillomavirus) type was applied in screening 51 biopsies from 42 patients. A resulting 36% (16/45) of the cholesteatomas were found to contain papillomavirus DNA, which hybridized under stringent conditions with an HPV-II DNA probe. In 3 cases the presence of HPV-II DNA could be confirmed by sequencing the PCR products. The mere presence of this HPV DNA does not prove an etiological role of this group of viruses in the induction of cholesteatomas. It does, however, identify another group of human proliferative lesions putatively linked to papillomavirus infections.

Congenital cholesteatoma

Since the late 1970s, the author has had the opportunity to prospectively study, document, and surgically manage 40 cases of congenital cholesteatoma. All cases met strict criteria for inclusion in the study, all were surgically and pathologically confirmed, and were definitively followed. During that same period, 38 cases were managed by other members of the otolaryngology department. It is the purpose of this thesis to critically study this personal and institutional experience, and to validate the rationale for early diagnosis and prompt and effective surgical intervention.