Carcinoma of the oesophagus is a common condition
accounting for 10 pet cent of gastrointestinal malignancies. Oesophageal
carcinoma arises in the mucosa. Subsequently, it tends to invade
the submucosa and the muscular layer and, eventually, contiguous
structures such as the tracheobronchial tree, the aorta, or the
recurrent laryngeal nerve. The tumor also tends to metastasize
to the periesophageal lymph nodes and, eventually, to the liver,
lungs, or both. . Alcohol, tobacco, Barrett oesophagus, asbestosis,
tylosis, coeliac disease, Plummer-Vinson syndrome, achalasia,
caustic stricture and radiation are known risk factors.
Oesophageal tumours are often diagnosed by endoscope
and barium studies. Sonography will occasionally demonstrate an
unexplained distal oesophageal mass but its great use is in evaluating
the liver, portal and para-aortic nodes and para-oesophageal areas
to demonstrate tumour spread. Oesophageal tumour usually spreads
longitudinally along the oesophageal wall thus there may be extensive
tumour spread without sonographically detectable mass lesions.
Endoscopic ultrasound is the most sensitive test to help determine
the depth of penetration of the tumor (T staging) and the presence
of enlarged periesophageal lymph nodes (N staging). . Endoscopie
ultrasound is ideally suited to TNM staging as it depends on the
depth of invasion of cancer and its involvement of various layers
of the esophageal wall.
The TNM system
Tl tumor invading submucosa or lamina propria.
T2 invasion of muscularis propria.
T3 invasion of adventitia.
T4 invasion of adjacent structures.
Stage 1 =T1, N0, M0.
Stage II A= T2-3, N0, M0.
Stage II B = T1/2, N1, M0.
Stage III = T3, N 1, M0 or T4, N0/1, M0.
Stage IV=T1-4, N0/1, Ml.
The normal thickness of the intra-abdominal oesophageal wall is
3.8 ± 1.2 mm. The five layers of the esophageal wall are well
seen on endoscopic ultrasound enabling such staging. However the
ability to stage nodal involvement is limited by the tact that
endoscopic ultrasound can detect lymph nodes of the primary tumor.
When endoscopic ultrasound is combined with abdominal sonography,
liver and upper abdominal lymph node metastases can be detected
and peritoneal metastases inferred in the presence of ascites.
Esophageal tumor is usually seen as an area of wall thickening
which is usually hypoechoic but which may present a more complex
echopattern. With cancer penetration the wall differentiation
is lost and the smooth outer border of the esophagus is no longer
seen. tumor invasion into the echogenic para esophageal fat can
be easily detected. Endoscopic ultrasound is also helpful in the
follow-up of patients with operative resection of cancer and with
non Hodgkin's lymphoma follow-up during radiotherapy or chemotherapy.
*Acute inflammation or corrosive injury
*Esophagitis or esophageal ulcération.
*Esophageal Crohn's disease.
*Right-sided heart failure.