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Présentation Clinique / Clinical setting
Femme de 31 ans se présentant pour douleur intense
quasi-permanente au siège d'une résection tumorale des tissus mous,
antrieure au niveau de sa jambe, il y a deux ans, avec le diagnostic
d'hémangiopéricytome. Une résection large du siège d'intervention
antérieure est réalisé.
Patient 31 yo female with an excruciating
pain non subsiding on the anterior aspect of the lower leg, in the
location of previous surgery of soft tissue tumor. Previous diagnosis:
hemangiopericytoma. Wide excision of the painful lesion is performed.
Radiologie / Radiology
IRM de la lésion antérieure objective la profondeur
de la lésion des tissus mous, et son caractère partiellement kystique. MRI of the previous soft tissue tumor, deep
in contact with the periostium, partly cystic.
Pathologie / Pathology
 
Dans les fragments de tissus mous
il est observé des nodules cellulaires
de taille variable.Ces nodules sont bien
circonscrits.
In the soft tissue sections,
cellular nodules are observed well
circumscribed.
Ces nodules présentent par
place des amas et des éléments disséquant
en files indiennes le tissu conjonctif péri-nodulaire. Ces nodules
sont formés de cellules cuboïdes semblant adoptés un arrangement
tantôt en nappe ou en amas.
Some show in the surrounding
connective tissue, clusters and indian
file pattern. Cuboid and ovoid cells are arranged in sheets in the central part of the nodules,
Ils présentent par ailleurs des foyers d'accumulation
de substance hyaline interstitielle.
Some interstitial
hyalin material is noted. 
Le PAS objective une positivit
pericellulaire, et il existe un engainement unicellulaire par
une trame rticulinique grle dans
les nappes cellulaire, dlimitant les amas.
PAS stain
discloses pericellular positivity. Silver
stain demonstrates a dense meshwork surroundind the cells individually,
and the cell clusters.
Dans certains fragments, la prolifération est
mal délimitée. Dans le tissu conjonctif
adjacent, il existe des structures angiomateuses.
The proliferation is ill-circumscribed
in some fragments. The surrounding connective tissue harbors angiomatous
formations.
Ces dernières exhibent des aspects de structures
glomiques hyperplasiques.
The latter shows a pattern of hyperplastic
glomus structures.
Immunohistochimie / Immunohistochemistry
Les cellules sont positives l'Actine
Muscle Lisse, cependant cette positivité est absente dans les
foyers compacts. Le CD34 est négatif,
de même les pancytokératines, et l'EMA.
The cells are positive to Smooth
Muscle Actin. Some central areas of the nodules are negative.CD34
is negative, so are the cytokeratins, and EMA.
La Proteine
S100 révèle la présence d'une positivité au niveau de cellules
fusiformes (schwannienne?) au sein de la prolifration.
PS100
reveals the presence of a small spindle cell component (schwann
cells?).
Pathologie Antérieure / Previous Pathology
Les lames des la tumorectomie antérieure
soumises pour évaluation dans la présentation actuelle montrent
une aspect typique d'hémangiopricytome, tant sur le plan architectural
(faible et moyen agrandissement),
The slides submitted from the
previous tumor exision for evaluation in the actual presentation,
show a typical hemangiopericytomatous pattern at low,
and medium power,
Absence d'atypie cytologique (
faible et moyen
agrandissement)
With no cytological atypia (low
and high power),
Engainement monocelulaire sur l'argentation.
Abundant reticulin
fibers surrounding the cells, and the vascular spaces.
En periphérie de certaines sections il existe
des foyers dont les aspects histologiques sont comparables la
lésion actuelle. Mais le matériel soumis est insuffisant pour une
évaluation immunohistochimique.
The tumor shows, in some peripheral areas,
histological patterns identical to the actual lesion. No additional
material was available for immunohistochemistry.
Diagnostic Proposé / Proposed diagnosis:
Tumeur du Glomus / Glomus tumor
(Ackerman's Surgical Pathology, 8 th Ed.)
Glomus tumor, also known as glomangioma, originates in the neuromyoarterial
glomus, a normal
arteriovenous shunt abundantly supplied with nerve fibers and fulfilling
a temperature-regulating function. The classical location of the
glomus tumor is the subungual region, but it can occur elsewhere
in the skin, soft tissues (particularly in the flexor surface of
the arms and about the knee), nerves, stomach, nasal cavity, and
trachea. It has also been reported in the sacrococcygeal region,
arising from the coccygeal body (glomus coccygeum) and associated
with coccydinia, but there is some question as to whether this is
a true neoplasm or simply a normal structure of this region.
Subungual lesions are always supplied by numerous nerve fibers and
are exquisitely painful, two features often absent in glomus tumors
arising elsewhere. The tumor may erode the terminal phalanx or even
present as an intraosseous lesion in this location. Superficial
lesions are well circumscribed. Glomus tumors in children tend to
be multiple and of an infiltrative nature. They may present clinically
as varicosities of the lower extremities.
Microscopically, glomus tumors consist of blood vessels lined by
normal endothelial cells and surrounded by a solid proliferation
of round or cuboidal "epithelioid" cells with perfectly round nuclei
and acidophilic cytoplasm. As seen under an electron microscope,
the tumor cells have features of smooth muscle rather than of pericytes.
Immunohistochemically, they manifest reactivity for myosin,vimentin,
actin, and basal lamina components but not for desmin. Numerous
substance Pcontaining nervefibers have been detected among the
glomus cells.
Three microscopic types of glomus tumor have been recognized:
solid, angiomatous, and myxoid. The solid type can be
confused with sweat gland tumor, melanocytic nevus, or metastatic
carcinoma. This is particularly the case when the tumor cells are
very epithelioid and/or grow in an Indian-file fashion. An oncocytic
variant of glomus tumor, in which the cytoplasm of the glomus
cells is packed with mitochondria, has also been described. Often
the diagnostic relationship between tumor cells and blood vessels
can be clearly seen only at the very periphery of the neoplasm.
Mast cells are common.
On rare occasions, glomus tumors behave in an aggressive fashion,
with local recurrences and invasion of adjacent structures. In other
instances, lesions with the typical cytoarchitectural features of
glomus tumor merge with a cytologically malignant tumor; these have
been designated glomangiosarcomas.
Theoretically, a de novo glomangiosarcoma should also exist, but
its morphologic recognition (particularly its distinction from vascular/epithelioid
forms of leiomyosarcoma) would be most difficult. No convincing
examples of metastasizing glomus tumors have been reported.
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