Usefulness of computed tomography Hounsfield unit density in preoperative detection of cholesteatoma in mastoid ad antrum

American Journal of Otolaryngology (Apr 2010)

Park MH, Rah YC, Kim YH, Kim JH;

PURPOSE: This study was performed to evaluate the usefulness of Hounsfield unit (HU) to better distinguish cholesteatoma from other inflammatory conditions in the mastoid ad antrum before primary mastoid surgery.

MATERIALS AND METHODS: We enrolled 82 patients who underwent tympanomastoidectomy for treatment of chronic otitis. Forty-one patients were pathologically diagnosed with cholesteatoma, whereas the others were diagnosed with inflammatory granulation. These lesions were confirmed, and HU was measured in preoperative computed tomography. The difference in HU between cholesteatoma and non-cholesteatoma tissues was analyzed, and the improvement in the diagnosis of cholesteatoma after inclusion of HU data was calculated.

RESULTS: The HU was calculated as 42.68 +/- 24.42 in the cholesteatoma group and 86.07 +/- 26.50 in the non-cholesteatoma group. The differences between the 2 groups were statistically different (Student t test, P<.01). By applying the HU, the sensitivity (51.2%-80.5%), specificity (80.5%-87.8%), positive predictive value (72.4%-86.8%), and negative predictive value (62.3%-81.8%) to diagnose cholesteatoma improved.

CONCLUSIONS: The HU density was found to be statistically different between cholesteatoma and inflammatory granulation tissue in mastoid antrum. An improved diagnosis of cholesteatoma was achieved after adjusting for the HU.

Pediatric cholesteatoma and variants in the gene encoding connexin 26

 

The Laryngoscope (Oct 2009)  James AL, Chadha NK, Papsin BC, Stockley TL

OBJECTIVES/HYPOTHESIS:: Connexin 26 is a gap junction protein encoded by the GJB2 gene. It is expressed in cholesteatoma, and mutations cause proliferative skin disorders and sensorineural hearing loss (SNHL). Deletions of GJB6, which encodes connexin 30, cause SNHL in a digenic manner with a heterozygous GJB2 mutation. We hypothesize that GJB2 and GJB6 mutations might influence the development of cholesteatoma. 

STUDY DESIGN:: Prospective observational study to identify GJB mutations in pediatric cholesteatoma. 

METHODS:: Peripheral blood samples from 98 children with cholesteatoma were screened for mutations in the GJB2 gene by direct sequencing of the coding region (exon 2 and the intron/exon boundary). Deletions of the GJB6 gene were tested using multiple ligation probe amplification methods. GJB status was compared with other populations and patient age and extent of cholesteatoma at presentation. 

RESULTS:: Fourteen children had at least one GJB2 variant (14%). Of these, three had two variants. Two of the variants were neutral polymorphisms. One child with the GJB2 genotype 35delG/35delG also had SNHL. No correlation was found between GJB2 status and patient age or cholesteatoma severity at presentation. No GJB6 deletions were found. 

CONCLUSIONS:: GJB2 gene variants are present in a minority of children with cholesteatoma, but may be more common than in normal populations. It is conceivable that alterations of connexin 26 expression could contribute to the multifactorial disease process in cholesteatoma by modifying the cell-to-cell communication that is important in proliferation and migration of keratinocytes. Laryngoscope, 2009.