DOG1 and CD117 are the antibodies of choice in the diagnosis of gastrointestinal stromal tumours.
OBJECTIVE
The histopathological diagnosis of gastrointestinal stromal tumours (GIST) is typically made based on a combination of clinical and morphological features supported by immunohistochemistry studies. The aim of this study was to examine the staining quality, sensitivity, specificity and utility of antibodies used commonly in GIST diagnosis.


RESULTS
Immunohistochemistry with a panel of antibodies [CD117, DOG1, protein kinase C (PKC)-theta, nestin, CD34, smooth muscle actin (SMA), desmin, S100 and CD171] was performed on whole sections from 187 GIST and 29 gastrointestinal mesenchymal tumours, and on several microarrays including 355 GISTs and 120 soft tissue sarcomas. Results showed that DOG1 and CD117 were the most sensitive and specific antibodies used in GIST diagnosis. PKC-theta and nestin were sensitive, but less specific, also staining other spindle cell tumours commonly considered in the differential diagnosis of GIST. CD34 staining was less sensitive than many of the other antibodies and of limited aid in diagnosis. The smooth muscle markers SMA and desmin, together with the neural marker S100, were unhelpful in confirming a diagnosis of GIST, but were particularly useful in the exclusion/diagnosis of other gastrointestinal mesenchymal tumour types.


CONCLUSIONS
In the majority of histologically suspected GISTs a combination of CD117 and DOG1 immunostaining is sufficient to confirm the histological diagnosis.
Novelli
Marco
M
Department of Pathology, University College London NHS Trust, University Street, London, UK. m.novelli@ucl.ac.uk
Rossi
Sabrina
S
Rodriguez-Justo
Manuel
M
Taniere
Philippe
P
Seddon
Beatrice
B
Toffolatti
Luisa
L
Sartor
Chiara
C
Hogendoorn
Pancras C W
PC
Sciot
Raf
R
Van Glabbeke
Martine
M
Verweij
Jaap
J
Blay
Jean Yves
JY
Hohenberger
Peter
P
Flanagan
Adrienne
A
Dei Tos
Angelo P
AP
D000075369:Anoctamin-1; D000906:Antibodies; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D018118:Chloride Channels; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000235:genetics; D003937:Diagnosis, Differential; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D040081:Protein Array Analysis; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism*; D012680:Sensitivity and Specificity
C476213:ANO1 protein, human; D000075369:Anoctamin-1; D000906:Antibodies; D014408:Biomarkers, Tumor; D018118:Chloride Channels; D004273:DNA, Neoplasm; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D019009:Proto-Oncogene Proteins c-kit