Human cochleae with three turns: an unreported malformation.
OBJECTIVE
The objective of this histologic study of archival temporal bone sections was to describe the morphology of human cochleae found with three turns, a previously unreported anomaly, found in three pairs of temporal bones.


METHODS
The authors conducted histopathologic processing and measurement of basilar membrane length. Basilar membrane length was compared with that found in six normal control bones.


RESULTS
Cochleae with three complete turns, rather than the usual two and a half turns, are described for the first time. All had longer than normal basilar membranes, with a mean length of 40.6 mm compared with a mean of 33.8 mm in the normal bones.


CONCLUSIONS
Human cochleae with three turns exist as an unreported anomaly. This is a new category of anomaly, not likely based on interruption of development.
Tian
Qing
Q
Healthcare Partners, Torrance, California 90057, USA.
Linthicum
Fred H
FH
Fayad
Jose N
JN
D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003051:Cochlea / Q000002:abnormalities*; D015834:Cochlear Diseases / Q000151:congenital* / Q000473:pathology; D000013:Congenital Abnormalities / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D035583:Rare Diseases; D012016:Reference Values; D012494:Sampling Studies; D013701:Temporal Bone / Q000473:pathology