9%20ECOGRAFIA%20ABDOMINAL%20COMO%20CUANDO%20DONDE

THE RETROPERITONEUM AND GASTROINTESTINAL TRACT 203
A
B
Figure 8.6 (A) Compression of the IVC by a large liver metastasis caused Budd–Chiari syndrome. This has been
relieved by the insertion of a metal stent into the IVC (arrows) under angiographic control. (B) Unusual case of a
small leiomyosarcoma in the IVC found incidentally. Normally they are larger, presenting with symptoms of IVC
obstruction.
Pathology of the adrenal glands
Adenoma
Small (less than 3 cm) solid adrenal nodules are a
common, incidental finding in non-symptomatic
patients (Fig. 8.8A).
Benign, non-hyperfunctioning adenomas account
for the majority of adrenal nodules, and are of no clinical
significance. Their incidence increases with age
and they are present in around 2% of adult autopsies.
Small nodules in asymptomatic patients generally
require no further action, but endocrine function
may be evaluated to rule out a functioning mass.
A hyperfunctioning adenoma (a determination
made by evaluation of the endocrine function),
although an essentially benign mass, usually
requires surgical resection.
As a solitary abdominal finding in a patient with
no relevant clinical history, it is generally safe to
assume a small adrenal nodule requires no further
action. However, because it is not possible to distinguish
benign, incidental nodules from other
forms of more serious pathology, incidental nodules
of greater than 4 cm should be investigated
further to confirm their benign nature. 8 Non-functioning
adenomas will remain stable in size on
ultrasound follow-up.
Metastasis
The adrenal glands are a common site for metastases,
particularly from lung, breast and bowel cancer.
Although frequently accompanied by liver
metastases, they may be present in the absence of
any other obvious abdominal deposits, and therefore
the adrenal glands should routinely be examined
when staging malignant disease.
The adrenal glands are also commonly involved
in non-Hodgkin’s lymphoma.
Like adenomas, they are often small, welldefined
and hypoechoic on ultrasound (Fig. 8.8B).
It is not possible to differentiate between benign
adenoma and metastasis on the ultrasound appearances
alone, but a small adrenal mass in the
absence of a known primary carcinoma is likely to
be benign, and will remain stable on follow-up. A
solitary adrenal mass in the presence of known carcinoma
requires biopsy for diagnosis.
Adrenal cysts
Simple cysts are uncommon in the adrenal gland,
but are easily differentiated from solid lesions with
ultrasound. Some cysts may be the sequelae of previous
haemorrhage, but most are simple, epithelial
cysts.