Learning Objectives: Genetics behind cholesteatoma formation.

In our country CWD tympanoplasty has been a widespread surgical technique in the recent decades to remove cholesteatoma. Therefore we meet several patients for regular check-ups, when the proper cleaning of the mastoid cavity is mandatory, otherwise severe inflammation may recur. The gold standard is the use of microscopes which allows good manipulation. However, to examine and clean hidden recesses, rigid or flexible endoscopes may be indispensable. Our technique is presented on a short video.

Uncleaned mastoid cavities filled with desquamation may behave like a cholesteatoma. Our working group tried to explain the genetical background of the different behavior of normal skin compared to the epithelium of the cholesteatoma. Previous studies have found aneuploidy of chromosome 8, copy number variation of c-MYC gene and the presence of elevated c-MYC protein level in cholesteatoma. We compared the expression of c-MYC gene in samples taken from acquired cholesteatomas, atheromas and normal skin samples using RT-qPCR. Significantly elevated c-MYC gene expression was found in cholesteatoma compared to atheroma and to normal skin samples. It implies a more prominent hyperproliferative phenotype that might be due to the presence of inflammation in acquired cholesteatoma.