The basement membranes in sarcomatoid carcinomas. An immunohistochemical study.
OBJECTIVE
Eight sarcomatoid carcinomas from various anatomical locations were investigated by immunohistochemical staining to laminin, type IV collagen and heparan sulfate proteoglycan, to study the characteristics of basement membranes at the interface between carcinomatous and sarcomatous tissues.


METHODS
Paraffin wax embedded tissue sections from representative tumor samples have been stained with specific antibodies, using the peroxidase-antiperoxidase technique.


RESULTS
In all cases several interruptions or discontinuities of the basement membrane staining pattern were seen. In 4 cases, larger defects or complete loss of staining was also noted. At these places, the boundaries between carcinomatous and sarcomatous tissue were often blurred.


CONCLUSIONS
Disruption and loss of basement membranes at interface between carcinomatous and sarcomatous tissues is a frequent finding in sarcomatoid carcinomas. These changes could be consistent with an epithelial origin of the sarcomatous component in these tumors by means of an epithelial-mesenchymal conversion mechanism.
Guarino
M
M
Department of Anatomical Pathology, Hospital of Treviglio, Italy.
Squillaci
S
S
Reale
D
D
Micoli
G
G
D000368:Aged; D001485:Basement Membrane / Q000276:immunology / Q000473:pathology*; D002296:Carcinosarcoma / Q000473:pathology*; D003094:Collagen / Q000276:immunology; D005260:Female; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D007797:Laminin / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011509:Proteoglycans / Q000276:immunology
D003094:Collagen; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D007797:Laminin; D011509:Proteoglycans