Histopathological basis for neurogenic thoracic outlet syndrome. Laboratory investigation.
OBJECTIVE
To the best of the authors' knowledge, no report exists that has demonstrated the histopathological changes of neural elements within the brachial plexus as a result of cervical rib compression.


METHODS
Four hundred seventy-five consecutive human cadavers were evaluated for the presence of cervical ribs. From this cohort, 2 male specimens (0.42%) were identified that harbored cervical ribs. One of the cadavers was found to have bilateral cervical ribs and the other a single right cervical rib. Following gross observations of the brachial plexus and, specifically, the lower trunk and its relationship to these anomalous ribs, the lower trunks were submitted for immunohistochemical analysis. Specimens were compared with two age-matched controls that did not have cervical ribs.


RESULTS
The compressed plexus trunks were largely unremarkable proximal to the areas of compression by cervical ribs, where they demonstrated epi- and perineurial fibrosis, vascular hyalinization, mucinous degeneration, and frequent intraneural collagenous nodules. These histological findings were not seen in the nerve specimens in control cadavers. The epineurium was thickened with intersecting fibrous bands, and the perineurium appeared fibrotic. Many of the blood vessels were hyalinized. The nerve fascicles contained frequent intraneural collagenous nodules in this area, and focal mucinous degeneration was identified.


CONCLUSIONS
Cervical ribs found incidentally may cause histological changes in the lower trunk of the brachial plexus. The clinician may wish to observe or perform further evaluation in such patients.
Tubbs
R Shane
RS
Department of Surgery, Division of Neurosurgery, University of Alabama at Birmingham, Alabama, USA. rstubbs@uab.edu
Louis
Robert G
RG
Wartmann
Christopher T
CT
Lott
Robert
R
Chua
Gina D
GD
Kelly
David
D
Palmer
Cheryl Ann
CA
Shoja
Mohamadali M
MM
Loukas
Marios
M
Oakes
W Jerry
WJ
D000368:Aged; D000369:Aged, 80 and over; D001917:Brachial Plexus / Q000473:pathology*; D002102:Cadaver; D016022:Case-Control Studies; D002573:Cervical Rib Syndrome / Q000150:complications / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D005355:Fibrosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D013901:Thoracic Outlet Syndrome / Q000209:etiology* / Q000473:pathology*