TY  - JOUR
AU  - Adam, Patrick
AU  - Hakroush, Samy
AU  - Hofmann, Ilse
AU  - Reidenbach, Sonja
AU  - Marx, Alexander
AU  - Ströbel, Philipp
TI  - Thymoma with loss of keratin expression (and giant cells): a potential diagnostic pitfall.A190
JO  - Virchows Archiv
VL  - 465
IS  - 3
SN  - 1432-2307
CY  - Berlin
PB  - Springer
M1  - DKFZ-2017-00150
SP  - 313 - 320
PY  - 2014
AB  - Due to its profound therapeutic consequences, the distinction between thymoma and T-lymphoblastic lymphoma in needle biopsies is one of the most challenging in mediastinal pathology. One essential diagnostic criterion favouring thymoma is the demonstration of increased numbers of keratin-positive epithelial cells by immunohistochemistry. Loss of keratin expression in neoplastic epithelial cells could lead to detrimental misdiagnoses. We here describe a series of 14 thymic epithelial tumours (11 type B2 and B3 thymomas, 3 thymic carcinomas) with loss of expression of one or more keratins. Cases were analysed for expression of various keratins and desmosomal proteins by immunohistochemistry and immunofluorescence and compared with 45 unselected type B thymomas and 24 thymic carcinomas arranged in a multitissue histological array. All 14 cases showed highly reduced expression of at least one keratin, three cases were completely negative for all keratins studied. Of the 14 cases, 13 showed strong nuclear expression of p63. Expression of desmosomal proteins was preserved, suggesting intact cell contact structures. Loss of expression of broad-spectrum-keratins and K19 was observed in 3 and 5 
KW  - CTNNB1 protein, human (NLM Chemicals)
KW  - Cadherins (NLM Chemicals)
KW  - beta Catenin (NLM Chemicals)
KW  - Keratins (NLM Chemicals)
LB  - PUB:(DE-HGF)16
C6  - pmid:24923897
DO  - DOI:10.1007/s00428-014-1606-6
UR  - https://inrepo02.dkfz.de/record/119408
ER  -