Neil Hand wrote:
> 
> Can anyone tell me a good specific immuno marker for thymomas?  A source
> and methodology if obscure would also be appreciated.
> 
> Thanks in advance.
> 
> Neil Hand,
> Histopathology Dept,
> queen's Medical Centre,
> Nottingham,
> England UK
> 
> ____________________________________________________________________
> Neil Hand
> Department Histopathology, University Hospital, Nottingham NG7 2UH.
> work : Tel: (0115) 924 9924 extension 43725
> ____________________________________________________________________


That's simple.

(1) The best is to demonstrate the presence of immature T cells within
the tumor. This can be achieved by staining for TdT, CD99 or CD1a. This
is so because lymphoid cells associated with other tumor types are
always mature.

(2) If the thymoma is of spindle cell type (type A thymoma), try
CD20/L26. If the spindly cells are positive, that is a strong support
for a diagnosis of thymoma, because CD20 practically never stains other
epithelial cells.


John K.C. Chan
Department of Pathology
Queen Elizabeth Hospital
Hong Kong