The value of c-kit mutational analysis in a cytokeratin positive gastrointestinal stromal tumour.
The expression of cytokeratins in gastrointestinal stromal tumours (GISTs) is rare and may lead to diagnostic confusion when it occurs. This report describes a metastatic GIST that stained strongly for cytokeratins, CD117, and CD34 in a patient who was previously diagnosed with gastric epithelioid angiosarcoma. A review of both tumours showed the same histological and immunohistochemical profiles, and c-kit molecular analysis revealed an insertional mutation at codon 558 of exon 11 in both tumours. Thus, pathologists should be aware that GISTs can occasionally express cytokeratins, and that c-kit mutational investigations may have a key diagnostic role and may prevent diagnostic mistakes that could have important clinical implications.
Rossi
G
G
Integrated Department of Diagnostic and Laboratory Services and Legal Medicine, Section of Pathologic Anatomy, University of Modena and Reggio Emilia, via del Pozzo 71, 41100 Modena, Italy. rossi.giulio@unimo.it
Sartori
G
G
Valli
R
R
Bertolini
F
F
Bigiani
N
N
Schirosi
L
L
Cavazza
A
A
Luppi
G
G
D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis* / Q000556:secondary; D006394:Hemangiosarcoma / Q000175:diagnosis; D006801:Humans; D007633:Keratins / Q000378:metabolism*; D009154:Mutation; D010386:Pelvic Neoplasms / Q000175:diagnosis / Q000556:secondary; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*; D013274:Stomach Neoplasms / Q000175:diagnosis*
D014408:Biomarkers, Tumor; D007633:Keratins; D019009:Proto-Oncogene Proteins c-kit