MALIGNANT PANCREATIC DISEASE

Ultrasound images Pancreatic carcinoma

                             Clinical features and management Carcinoma of the pancreas is a major cause of cancer-related death. It carries a very poor prognosis with less than 5% 5 year survival,10 related to its late presentation. The presenting symptoms depend on the size of the lesion, its position within the pancreas and the extent of metastatic deposits. Most pancreatic carcinomas (60%) are found in the head of the pancreas, and patients present with the associated symptoms of jaundice due to obstruction of the common bile duct (Fig.BELOW). Carcinomas located in the body or tail of pancreas do not cause obstructive jaundice.
The majority (80%) of pancreatic cancers are ductal adenocarcinomas, most of which are located in the head of pancreas. The rest comprise a mixed bag of less common neoplasms and endocrine tumours.
                          Endocrine tumours, which originate in the islet cells of the pancreas, tend to be either insulinomas (generally benign) or gastrinomas (malignant).
These present with hormonal abnormalities while the tumour is still small and are more amenable to detection by intraoperative ultrasound than by conventional sonography.
                         Mucin-secreting tumours (Fig. E), which appear predominantly cystic on ultrasound, tend to be located in the body or tail of pancreas and follow a much less aggressive course than adenocarcinomas, metastasizing late. These tumours, though comparatively rare, have a much higher curative rate with surgery.
                               Metastatic deposits from primary pancreatic adenocarcinoma occur early in the course of the disease, and 80% of patients already have nodal disease or distant metastases in the lungs, liver or bone by the time the diagnosis is made, which accounts for the poor prognosis.
Surgical removal of the carcinoma by partial pancreaticoduodenectomy, the Whipples procedure, is potentially curative but only 20% of patients have a
tumour which is potentially resectable, and the 5-year survival rate following resection is less than 5%.13 Over 70% of patients die from hepatic metastases
within 3 years postoperatively. Differential diagnoses of pancreatic masses must always be considered (Table : 1.1 ); focal lesions in the pancreas may represent inflammatory rather than malignant masses. An ultrasound-guided biopsy is sometimes useful in establishing the presence of adenocarcinoma if the biopsy is positive, but the sensitivity of this procedure is relatively low. The value of a negative biopsy is dubious because of the inflammatory element surrounding many carcinomas.

Endosonography-guided biopsy, however, has high sensitivity and specificity for diagnosing pancreatic cancer, and is also useful in patients with a previous negative biopsy in whom malignancy is suspected. ERCP may also be used to insert a palliative stent in the common bile duct, to relieve biliary obstruction.
The detection of a pancreatic carcinoma by ultrasound is usually followed by a CT scan for staging purposes as this will demonstrate invasion of peripancreatic fat, vascular involvement and lymphadenopathy.

(fig. a )The ultrasound images common bile duct, c, is obstructed by a large hypoechoic solid mass at its lower end (calipers),
which is a carcinoma in the head of the pancreas.

(Fig. b)
Ultrasound images TS through the head of the pancreas, which is swollen by a
hypoechoic adenocarcinoma (arrow).

fig c. The tumour in (B) displays considerable vascularity on colour Doppler. (Note the
colour sensitivity setting has been reduced to accommodate this, so eliminating low-velocity flow from the splenic vein.)

fig. d , Ultrasound images Tumour in the head of the pancreas (arrows), confirmed by CT

fig. e

Complex cystic mass in the head of the pancreas,
confirmed as a cystadenocarcinoma

(fig.f ) A complex mass (m) between the spleen (S) and the left kidney is a large carcinoma
of the tail of the pancreas.

(fig g) ultrasound images of Dilated pancreatic duct due to a carcinoma in the head (arrow)

(fig h) Ultrasound images of Colour Doppler helps to differentiate the dilated pancreatic duct (measured), which does not contain flow, from the splenic vein posterior to the duct.

(fig. I )Endoscopic retrograde cholangiopancreatography (ERCP) demonstrating a long stricture of the pancreatic
duct (arrow) involving the side branches, in a large pancreatic carcinoma. The CBD is compressed (arrowhead) by
nodes, causing biliary dilatation. A palliative stent was inserted.

(Table 1.1 ) Differential diagnoses of focal pancreatic masses

Mass                                                    Characteristics
Solid Adenocarcinoma                 Hypoechoic, usually in the head of pancreas
Focal acute pancreatitis               Hypoechoic. Clinical history of pancreatitis
Focal chronic pancreatitis           Hyperechoic, sometimes with calcification.
                                                               History of pancreatitis
Endocrine tumour                         Less common. Small, hypoechoic, well-defined
Metastases                                       manifestation, widespread disease
Cystic  Pseudocyst                        History of pancreatitis
Mucinous tumour                         Less common than adenocarcinoma,
                                                             tending to form in the body or tail  of pancreas.
                                                             Favourable
prognosis following resection

Necrotic or haemorrhagic tumour Simple cyst                                               

Rare. Exclude polycystic disease by scanning the liver and kidneys

LiveJournal Tags: Ultrasound images of solid adenocarcinoma,ultrasound images acute pancreatitis,ultrasound images focal chronic pancreatitis,ultrasound images endocrine tumour

 

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