ARGYROPHILIC NUCLEOLAR ORGANIZER REGIONS IN AUDITORY MEATAL SKIN AND MIDDLE-EAR CHOLESTEATOMA

Comparative silver-staining of argyrophilic nuclear organizer regions (AgNORs) was performed to study the proliferative activity of auditory meatal skin and middle ear cholesteatoma. AgNOR expression patterns w ere counted by standardized methods in two centres, Bochum and London, and mean numbers of dots per nucleus were calculated. Specimens of no rmal auditory meatal skin showed 1.54 dots/nucleus (n = 12) in the Boc hum study, whereas cholesteatoma had 3.71 dots/nucleus (n = 21). In th e London study normal meatal skin showed two dots/nucleus (n = 4), whe reas acquired cholesteatoma (n = 8) gave a mean of 4.90 dots/nucleus a nd congenital cholesteatoma a mean of 4.70 dots/nucleus (n = 2). Our f indings confirm the hyperproliferative state of middle ear cholesteato ma, suggest that the congenital variety of cholesteatoma may have a si milar activity and indicate that AgNOR staining is a useful technique for assessing cellular proliferation in cholesteatoma and objectifying and quantifying its aggressive behaviour.