5 research outputs found
Diagnostic morphological features of PDGFRA-mutated gastrointestinal
Daum O., Grossmann P., Vanecek T., Sima R., Mukensnabl P., Michal M. (2006): Diagnostic morphological features of PDGFRA-mutated gastrointestinal stromal tumors: Molecular genetic and histological analysis of 60 cases of gastric GISTs. Ann. Diagn. Pathol. In Press Summary In this study, 60 gastrointestinal stromal tumors (GISTs) of the stomach were analyzed to elucidate the possible relation of their morphology to mutation status of KIT and PDGFRA genes. The patients included 27 men and 33 women with a mean age of 63,8 years (range 12 to 92). Only one tumor occurred before the age of 21 years. KIT mutations were detected in 31 cases (51,7%), PDGFRA mutations in 22 cases (36,7%), and seven cases (11,7%) were KIT and PDGFRA wild type. When the mutation status was correlated with histological features of the tumors, epithelioid or mixed epithelioid/spindle cell pattern and mast cell infiltration were found as the most reliable signs of PDGFRA mutation. Neoplastic rhabdoid cells and multinucleated giant cells, also previously reported as features of PDGFRA mutated GISTs, seemed to be less specific but still helpful markers in our study. Finally, tumor infiltrating lymphocytes and myxoid stroma do not seem to be valuable histological signs. Daum O., Klecka J., Ferda J., Treska V., Vanecek T., Sima R., Mukensnabl..
SOX10 and Olig2 as negative markers for the diagnosis of ependymomas: An immunohistochemical study of 98 glial tumors
SOX10 belongs to the family of transcription
factors essential for the development of neural crest,
peripheral nervous system and melanocytes. It is
presently used in histopathology as a marker of
melanocytic differentiation. SOX10 is expressed in
normal brain tissue in oligodendrocytes, but the
information about SOX10 expression in primary tumors
of the central nervous system is quite limited. In this
study, we examined the expression of SOX10 and Olig2
by immunohistochemistry in a series of 98 glial tumors
and explored their specificity and sensitivity for
differential diagnosis of ependymal vs non-ependymal
tumors. In addition, we examined the expression of
EMA and CD99 in ependymal tumors. SOX10 and
Olig2 staining were scored as negative if no positive
cells or only a few positive cells (typically up to 1-3%)
were found. In all other instances, SOX10 or Olig2
staining was scored as positive. Out of 44 examined
ependymal tumors none was found to express SOX10
and 7 specimens showed only a few SOX10-positive
cells that likely corresponded to entrapped nonneoplastic oligodendrocytes. In contrast, non-ependymal
tumors expressed SOX10 in 26/54 (48%) specimens.
Olig2 was positive in 5 out of 44 ependymomas (11%)
and 50 out of 54 (93%) non-ependymal tumors
(astrocytomas and oligodendrogliomas). EMA and CD99
expression was found in 33/44 (75%) and 11/44 (25%)
of ependymomas, respectively. SOX10-positivity rules
out the diagnosis of ependymoma among other glial
tumors with high confidence