DNA analysis of human cholesteatomas.
OBJECTIVE
The hypothesis tested in this article is that if cholesteatomas are a low-grade squamous cell neoplasm, then evidence of genetic instability, in the form of abnormal or aneuploid amounts of DNA, should be evident.


BACKGROUND
Cholesteatoma is a destructive lesion of the middle ear and/or mastoid process that produces complications by erosion of the temporal bone. The clinical hallmarks of cholesteatomas, namely invasion, migration, uncoordinated proliferation, altered differentiation, aggressiveness, and recidivism, are traits typically associated with the neoplastic cell. However, there is little evidence to support or refute the speculation that cholesteatomas are a low-grade squamous cell neoplasm. the existence of defects in the genetic complement of the major cellular constituents comprising a cholesteatoma, fibroblasts and keratinocytes, would support the speculation that cholesteatomas are a neoplasm, since cancers commonly manifest quantitative and qualitative alterations in the normal euploid complement of genetic information, resulting in a cell that has an abnormal or aneuploid amount of DNA.


METHODS
DNA content (ploidy) within cholesteatoma tissues was measured by flow cytometry and image analysis.


RESULTS
The DNA content of 11 human cholesteatomas and nine postauricular skin specimens was analyzed using flow cytometry, while the DNA content of 10 cholesteatoma specimens was analyzed using image analysis. Interpretable data was obtained from 10 cholesteatoma specimens and six postauricular skin specimens. One cholesteatoma specimen demonstrated an abnormal aneuploid DNA content, whereas the remaining nine cholesteatomas and the six postauricular skin specimens demonstrated a normal euploid DNA content.


CONCLUSIONS
We conclude that, due to the lack of overt genetic instability, as evidenced by the presence of a normal euploid DNA content, cholesteatomas are not low-grade neoplasms.
Desloge
R B
RB
Department of Otolaryngology/Head and Neck Surgery, Manhattan Eye, Ear, and Throat Hospital, New York, NY 10021, USA.
Carew
J F
JF
Finstad
C L
CL
Steiner
M G
MG
Sassoon
J
J
Levenson
M J
MJ
Staiano-Coico
L
L
Parisier
S C
SC
Albino
A P
AP
D000328:Adult; D000368:Aged; D000782:Aneuploidy; D002648:Child; D002781:Cholesteatoma / Q000235:genetics* / Q000473:pathology; D004247:DNA / Q000032:analysis*; D004428:Ear Neoplasms / Q000235:genetics / Q000473:pathology; D004432:Ear, Middle / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D018307:Neoplasms, Squamous Cell / Q000235:genetics / Q000473:pathology
D004247:DNA