F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología
Abstract
Background: Elastofibroma dorsi is a benign
soft tissue lesion composed of abnormal elastic fibers.
Degenerated elastic fibers in skin and liver are
associated with clusterin, an apoprotein that shares
functional properties with small heat shock proteins. We
evaluated the staining pattern and possible role of
clusterin in elastofibroma dorsi. Material and methods:
Twenty-one subcutaneous elastofibromas from the
scapular region were evaluated with Elastica van Gieson
and Orcein stains, immunohistochemically with
antibodies to clusterin, smooth muscle actin, S-100,
vimentin and CD34 and correlated with clinical data
with respect to physical trauma. Results: Clusterin
correlated with the staining pattern of Elastica van
Gieson and labelled abnormal broad coarse fibrillar and
globular elastic fibers in all elastofibromas. Orcein stains
additionally identified fine oxytalan fibers which were
not stained by clusterin. Clusterin staining was observed
only on the outside of the elastin fibers, while the cores
of fibers and globules were unstained. 4/21
elastofibromas showed cellular nodules with a myxoid/
collagenous stroma. The round to oval cells showed
cytoplasmic staining with vimentin and clusterin; CD34
labelled mostly cell membranes. The cells lacked SMA
and S-100 expression. The central areas of the nodules
were devoid of elastic fibers, but the periphery contained
coarse fibers and globules. 9/11 patients, for whom
clinical data were available, reported trauma to the
scapular region. Conclusion: Many investigated ED
were associated with trauma, which supports a reactive/
degenerative etiology of ED. The abnormal large elastic
fibers in all ED were enveloped by clusterin. Clusterin
deposition may protect elastic fibers from degradation
and thus contribute indirectly to the tumor-like
presentation of ED