38 yo male complaining
of an upper lumbar mass for 2 months, inflammatory type, painful, irradiating
to the left knee. MRI discloses a paravertebral left mass with extension
to medullary canal.
Male de 38 ans,
se plaignant depuis 2 mois d'une masse douloureuse lombaire haute, avec
irradiation de la douleur au genou gauche. L'IRM rvle une masse paravertbrale
gauche de D12 L1 avec expansion intracanalaire.
A surgical biopsy is
Une biopsie chirurgicale
Imprints for the material
Empreintes du materiel
Primitive Neuro-Ectodermal Tumor
Facts about PNET
Ewing's sarcoma )
- PNET are morphologically
indistinguishable from Ewing's sarcoma of the skeletal system. Most
of the patients are adolescents or young adults, and the usual sites
of involvement are the soft tissues of the lower extremity and paravertebral
region. The course is aggressive and distant metastases are common,
particularly to lung and skeleton.
- the presence of a consistent
chromosomal translocation (11;22), present in about 90% of the cases,
which leads to the production of a chimeric transcript that recognizes
a cell membrane protein of yet unknown function (p30/32 MIC 2; CD99),
- tumors located in bone
are more likely to exhibit a more undifferentiated phenotype, whereas
those located in soft tissues( Neuroepithelioma) including most thoracopulmonary
examples (Askin), tend to display various degrees of neuroepithelial
differentiation. The prognosis seems to be the same.
- The differential diagnosis
of Ewing's sarcoma/PNET of soft tissues includes embryonal and alveolar
rhabdomyosarcoma (especially the solid variant of the latter), malignant
lymphoma, and the rhabdoid tumor.
(Ackermann's Surgical Pathology,