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Retroclival ecchordosis physaliphora: MR imaging and
review of the literature.
Mehnert F, Beschorner R, Kuker W, Hahn U, Nagele T.
Department of Neuroradiology, University of Tuebingen, Hoppe-Seyler-Str 3,
D-72076 Tuebingen, Germany.
Background and Purpose. Ecchordosis physaliphora (EP), found in about 2% of
autopsies, is a clinically inconspicuous notochordal remnant appearing at
the dorsal wall of the clivus.
To our knowledge, a systematic review of its
MR features does not exist.
The aim of this study was to describe the MR
imaging findings of incidentally found retroclival EP with special respect
to its differentiation from intradural chordomas.
Methods. We reviewed 300
consecutive 1.5-T MR imaging studies that included thin-section transverse
T2-weighted images of the skull base for the presence of a retroclival EP.
In cases in which an EP was identified, two neuroradiologists observed MR
signal intensity characteristics, contrast enhancement, size, form, stalk of
EP, and signal intensity changes of the adjacent clivus.
Results. Five cases
with retroclival EP were found (incidence, 1.7%).
In all cases, the
ecchordoses was hyperintense on T2-weighted images and hypointense on
T1-weighted images.
Contrary to the reported findings in chordomas, none of
the lesions showed contrast enhancement.
In four cases, there were signal
intensity changes in the adjacent clivus.
A stalklike connection between
clivus and EP was seen in three patients.
Conclusion. Because of the benign
character of EP and the difficulties in its histopathologic differentiation
from chordomas, precise knowledge of the radiologic characteristics of EP is
important.
On the basis of these five cases and a review of literature,
contrast enhancement and the presence of clinical symptoms seem to be highly
reliable parameters in the differential diagnosis of intradural chordoma and
EP.
PMID: 15569763 [PubMed - indexed for MEDLINE]
Source: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15569763
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