Learning objectives
1.
To review the multirow computed tomography (CT) pattern of GISTs,
in primary diagnosis and follow-up.
2.
To expose a tailored CT / CTA (CT Angiography) acquisition and image processing protocol for the correct diagnosis and staging of GISTs.
Background
Gastrointestinal stromal tumors (GISTs) are the most common (80%) mesenchymal neoplasms affecting the gastrointestinal tract (GI-tract) and represent about 5% of all sarcomas [1].
GISTs are usually solitary,
but may also be multiple in a small number of cases (Fig.1),
typically occuring in adults (median age of 55-60 years),
with an incidence rate of 10 to 20 new cases per million/year [2].
GISTs are defined as KIT-positive mesenchymal spindle-or-epithelioid-cells,
affecting the GI-tract,
omentum,
or mesentery.
It is now believed that GISTs are arisen from the...
Imaging findings OR Procedure details
Contrast-enhanced CT is a powerful technique for GIST diagnosis,
allowing for characterizationof tumors.
[5] Indeed,
CT scan represents the most suitable method for: determining size,
shape and extention of GISTs; evaluating lesion uniformity (expressed in Hounsfield Units) and enhancing patterns; and staging (presence of liver,
peritoneal or other metastases).
CT appearances of GISTs are various,
depending on their localization and size.
Small GISTs are well-demarcated spherical and homogeneus soft tissue masses.
The lesion arises on the inner aspect of the muscle wall or muscularis mucosae...
Conclusion
GISTs are the most common non-epithelial neoplasms of GI tract,
defined as KIT-positive mesenchymal spindle-or-epithelioid-cells neoplasm,
occurring primarily in the GI-tract,
omentum,
or mesentery.
GISTs arise from the muscularis propria of the bowel wall and,
when they reach a huge size,
the mass tend to extend towards the extramural and intraluminal layers.
Frequently,
benign GISTs (size 2 ≥ 5 cm and mitotic count ≤ 5/50 HPF) rarely give metastasis.
Indeed,
metastases represent a typical signs of malignancy,
including liver involvement and intra-abdominal dissemination.
Lymph node...
References
[1] Joensuu H,
Fletcher C,
Dimitrijevic S,
Silberman S,
Roberts P,
Demetri G.
Management of malignant gastrointestinal stromal tumours.
Lancet Oncol 2002; 3: 655-664
[2] Nilsson B,
Bumming P,
Meis-Kindblom JM,
Odén A,
Dortok A,
Gustavsson B,
Sablinska K,
Kindblom LG: Gastrointestinal stromal tumors: the incidence,
prevalence,
clinical course,
and prognostication in the preimatinib mesylate era - a population-based study in western Sweden.
Cancer 2005,
103:821-829.
[3] Heinrich MC,
Corless CL,
Duensing A,
et al.
PDGFRA activating mutations in gastrointestinal stromal tumors.
Science 2003;299:708–710.
[4]...