Expression of actin isoforms and intermediate filament proteins in childhood orbital rhabdomyosarcomas.
The diagnosis of orbital rhabdomyosarcoma (RMS) in childhood gives rise to several clinical and anatomo-pathological problems. Antibodies recognizing structural proteins and cytoskeletal components have been shown to increase the diagnostic accuracy of different neoplastic lesions. In this study we examined anatomo-clinically and, where possible, by means of immunohistochemistry and electron microscopy, a series of 14 cases of orbital RMS in childhood. In the 12 cases studied by immunohistochemistry, desmin was always present, although showing variable patterns, and alpha-sarcomeric actin was found in 10 cases. alpha-Smooth muscle actin was always absent. The other markers tested (myoglobin, polyclonal actin, vimentin and enolase) proved unreliable for several reasons. We conclude that antibodies against desmin and alpha-sarcomeric actin are useful for the diagnostic definition of RMS. In addition, immunohistochemical analysis supplies data regarding the degree of tumor differentiation and may be applied to monitor radio- and chemotherapy.
Cintorino
M
M
Department of Pathology, University of Siena, Italy.
Vindigni
C
C
Del Vecchio
M T
MT
Tosi
P
P
Frezzotti
R
R
Hadjistilianou
T
T
Leoncini
P
P
Silvestri
S
S
Skalli
O
O
Gabbiani
G
G
D000199:Actins / Q000032:analysis*; D000293:Adolescent; D000912:Antibodies, Neoplasm / Q000276:immunology; D014408:Biomarkers, Tumor / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007381:Intermediate Filament Proteins / Q000032:analysis*; D008297:Male; D008854:Microscopy, Electron; D009918:Orbital Neoplasms / Q000032:analysis* / Q000175:diagnosis; D012208:Rhabdomyosarcoma / Q000032:analysis* / Q000175:diagnosis
D000199:Actins; D000912:Antibodies, Neoplasm; D014408:Biomarkers, Tumor; D007381:Intermediate Filament Proteins