KRAS, EGFR, PDGFR-α, KIT and COX-2 status in carcinoma showing thymus-like elements (CASTLE)
1 Institute of Pathology, Klinikum Bayreuth, Preuschwitzerstraße 101, Bayreuth 95445, Germany
2 Clinic of Trauma and Reconstructive Surgery, Klinikum Bayreuth, Preuschwitzerstraße 101, Bayreuth 95445, Germany
3 Pathologielabor Zams, Klostergasse 1, Zams 6511, Austria
4 Department of Pathology, University Hospital, INF 220/221, Heidelberg 69120, Germany
5 General practitioner, Moselstraße 1, Oberbettringen 73529, Germany
6 Department of Pathology, University Hospital, Robert-Koch-Straße 40, Göttingen 37075, Germany
7 Institute of Pathology/Lademannbogen Laboratories, Lademannbogen 61-63, Hamburg 22339, Germany
8 Pathologisch-Bakteriologisches Institut, Kaiserin-Elisabeth-Spital, Huglgasse 1-3, Vienna 1150, Austria
9 Department of Pathology and Neuropathology, University Hospital Essen, Hufelandstraße 55, Essen 45122, Germany
10 Department of Pathology, University Hospital Erlangen, Krankenhausstr. 10-12, Erlangen 91054, Germany
Diagnostic Pathology 2014, 9:116 doi:10.1186/1746-1596-9-116Published: 16 June 2014
CASTLE (Carcinoma showing thymus-like elements) is a rare malignant neoplasm of the thyroid resembling lymphoepithelioma-like and squamous cell carcinoma of the thymus with different biological behaviour and a better prognosis than anaplastic carcinoma of the thyroid.
We retrospectively investigated 6 cases of this very rare neoplasm in order to investigate the mutational status of KRAS, EGFR, PDGFR-α and KIT, as well as the immunohistochemical expression pattern of CD117, EGFR and COX-2, and possibly find new therapeutic targets.
Diagnosis was confirmed by a moderate to strong expression of CD5, CD117 and CK5/6, whereas thyroglobulin, calcitonin and TTF-1 were negative in all cases. Tumors were also positive for COX-2 and in nearly all cases for EGFR. In four cases single nucleotide polymorphisms (SNPs) could be detected in exon 12 of the PDGFR-α gene (rs1873778), in three cases SNPs were found in exon 20 of the EGFR gene (rs1050171). No mutations were found in the KIT and KRAS gene.
All tumors showed a COX-2 expression as well as an EGFR expression except for one case and a wild-type KRAS status. No activating mutations in the EGFR, KIT and PDGFR-α gene could be detected. Our data may indicate a potential for targeted therapies, but if these therapeutic strategies are of benefit in CASTLE remains to be determined.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1658499296115016 webcite