Pancreas Review

Mucinous Cystic Tumors

- AKA Mucinous cystadenoma or cystadenocarcinoma - Uncommon - Slow-growing tumor that arises from the ducts - Usually malignant (cystadenocarcinoma) - Can be benign (mucinous cystadenoma) - Most often occurs in middle aged to elderly females

Serous Cystic Tumors

- AKA serous cystadenoma - Rare - Benign, well-circumscribed multiple tiny cysts - Most often occurs in elderly females

Clinical Presentation of acute pancreatitis

- Acute onset of persistent severe epigastric pain - Nausea - Emesis - In patients with cholelithiasis, pain is localized - In patients with pancreatitis secondary to alcohol abuse, pain is poorly localized - Pain may radiate toward the back and last several days

Tail of the pancreas

- Begins to the left of the lateral border of the aorta and extends toward the splenic hilum - Splenic vein is the posterior border of the body and tail. - Splenic artery forms the superior border of the tail. - Stomach is the anterior border of the tail.

Agenesis

- Complete agenesis is incompatible with life - Partial agenesis of the body and tail with hypertrophy of the pancreatic head is the most common manifestation.

Lab Tests: Glucose

- Controls the blood sugar level on the blood stream. - Increase in glucose levels indicates - Diabetes - Chronic liver disease

Lab Tests: Amylase

- Digestive enzyme for carbohydrates - Secreted by the pancreas, parotid gland, GYN system, and the GI system - A serum amylase twice the normal value indicates acute pancreatitis

Sonographic Findings of chronic pancreatitis

- Echogenicity of the pancreas increases with a mixture of hypoechoic and hyperechoic foci throughout. - Size of the gland is reduced - Boarders are irregular - Pancreatic duct becomes irregular and dilated - Calcifications commonly found throughout gland and ducts

Lab Tests: Lipase

- Enzyme excreted specifically by the pancreas that parallels the level of amylase. - Test used to assess drainage of the pancreas

Sonographic features of a pseudocyst

- Fluid collection and edema frequently develop in patients with pancreatitis - Most commonly found in the lesser sac in the peripancreatic soft tissues - Between the stomach, pancreas, and spleen. - Important to differentiate between the fluid-filled stomach and a pseudocyst Associated findings: - Ascites - Thickening of the GB wall and/or GI tract wall

Neck of the pancreas

- Found directly anterior to the portal-splenic confluence or superior mesenteric vein - The portal vein is formed posterior to the neck by the junction of the superior mesenteric and splenic veins. - The neck is located between the pancreatic head and body and often is included as "part of the body" of the gland.

Associated findings of chronic pancreatitis

- Hypercalcemia (elevated calcium levels) - Hyperlipidemia (elevated fat levels) - Pancreas become fibrous and changes shape - Pancreatic ductal lithiasis

Clinical findings of chronic pancreatitis

- Hypogastric pain radiating toward the back - Pancreatic insufficiency - Nausea - Emesis - Fatty stools (yellowish)

Body of the pancreas

- Largest section of the pancreas - Anterior to the aorta and celiac axis (superior mesenteric, common hepatic, and left gastric arteries), left renal vein, adrenal gland, and kidney - Tortuous splenic artery is the superior border of the gland. - The anterior border is the posterior wall of the antrum of the stomach. - The neck of the pancreas forms the right lateral border. - The splenic vein courses across the posteromedial surface of the pancreas to join the main portal vein.

Head of the pancreas

- Most inferior portion of the gland - Lies anterior to the IVC, to the right of the portal-splenic confluence, inferior to the main portal vein and caudate lobe of the liver, and medial to the duodenum as it "lies in the lap" of the C-loop of the duodenum. - The splenic vein forms the posterior medial border of the pancreas. - The superior mesenteric vein crosses anterior to the uncinate process of the head of the gland and posterior to the neck and body of the pancreas. - The uncinate process is the small, curved tip at the end of the head of the pancreas.

Pseudocysts

- Pancreatic and parapancreatic fluid collections can develop. - Fluid collections usually resolve spontaneously, but those that do not are classified as pseudocysts. - Pseudocysts are always acquired; they result from trauma to the gland or from acute or chronic pancreatitis. - Pseudocysts develop in 10 - 20% of patients with acute pancreatitis. - Pseudocysts develop 4 - 6 weeks after the onset of pancreatitis. - Pseudocyst: a collection of fluid that arises from the loculation of inflammatory processes, necrosis, or hemorrhage. - Pancreatic pseudocyst: develops when pancreatic enzymes escape from the gland and break down tissue to form a sterile abscess somewhere in the abdomen. - They generally take on the contour of the available space around them and are therefore not always spherical, as true cysts are. - More than one pseudocyst may be present.

Vascular supply of the pancreas

- Pancreaticoduodenal artery supplies the pancreatic head and part of the duodenum. - Splenic artery supplies the pancreatic body and tail. - Drained through the tributaries of the splenic and superior mesenteric veins.

Sonographic Findings of Adenocarcinoma

- Poorly defined mass - Hypoechoic to isoechoic - Pancreatic boarders become irregular and enlarged - Pseudocysts - Metastatic spread Differential diagnosis: - Focal pancreatitis

Complications of pancreatitis

- Pseudocysts (most common) - Pancreatic Ascites - Hemorrhagic Pancreatitis - Phlegmonous Pancreatitis - Pancreatic Abscess

Annular pancreas

- Rare anomaly where the head of the pancreas surrounds the head of the duodenum. - More common in males

Pancreas divisum

- Rare condition caused by the lack of complete pancreas formation in utero - Difficult to diagnose via U/S

Ectopic pancreatic tissue

- The most common pancreatic anomaly - Pancreatic tissue may be found in various places throughout the abdomen and pelvis - Stomach, duodenum, small bowel, large bowel - Usually small (0.5 - 2 cm) - Usually form in intramural nodules

Sonographic Scan Technique

- The stomach and duodenum can obstruct much of the pancreas when they are gas-filled. - Position the patient in the semi-erect position and have them ingest 32-300 ml of fluid through a straw. - This will fill the antrum of the stomach and the duodenum with liquid providing an excellent imaging widow.

Metastatic Disease to the Pancreas

- Uncommon (10% of cancer patients) - Primary tumors that metastasize to the pancreas - Melanomas - Breast tumors - GI tumors - Lung tumors

Cystic lesions of the pancreas

1. Solitary Pancreatic Cyst 2. Multiple Pancreatic Cysts - Autosomal Dominant Polycystic Disease - Von Hippel-Lindau Syndrome - Cystic Fibrosis

Gastrinoma (G-Cell Tumor)

2nd most common functioning islet-cell tumor (18%) - Frequently multiple - Usually malignant (60%) - Treatment - total gastrectomy with tumor removal - Pancreatic tumors that cause excessive amounts of gastrin to be produced - Gastrin stimulates stomach to secrete large amounts of hydrochloric acid and pepsin - Leads to peptic ulceration of the stomach/small intestine - Excessive persistent diarrhea

Echogenicity of the pancreas

> liver/spleen

Phlegmonous Pancreatitis

A phlegmon is an inflammatory process that spreads along fascial pathways, causing localized areas of diffuse inflammatory edema of soft tissue that may proceed to necrosis - Extension outside the gland occurs in 18% to 20% of patients with acute pancreatitis. - Involves the lesser sac, left anterior pararenal space, and transverse mesocolon

Hemorrhagic Pancreatitis

A rapid progression of acute pancreatitis where pancreatic blood vessels rupture and hemorrhage results. The hemorrhage is contained within the pancreas. - When blood vessels rupture due to hemorrhagic pancreatitis and the fluid accumulates outside of the pancreas, a hemorrhagic pseudocyst develops.

Key differences between chronic and acute pancreatitis

Acute Pancreatitis - Amylase and lipase almost always elevated - Usually involves entire gland Chronic Pancreatitis - Amylase and lipase usually have normal levels - Usually involves patchy fibrotic disease

Congenital anomalies

Agenesis Pancreas divisum Ectopic pancreatic tissue Annular pancreas

Endocrine Pancreatic Neoplasms

Arise from the islet cells of the pancreas - Slow growth rate Classified into: Functional - Insulinoma - Gastrinoma Nonfunctional - Adenocarcinoma AND Benign or Malignant

Common causes of acute pancreatitis

Biliary tract disease (most common) - 40 - 60% of pt. have gallstones Alcohol abuse (2nd most common) Trauma Pregnancy

Pancreatic Echotexture

Compared to the liver, the normal pancreas is: - Slightly more echogenic - Slightly more course Pediatric patients have less echogenic pancreases than adult patients. Diabetics have very echogenic pancreases.

Nonfunctional Endocrine Pancreatic Neoplasms

Comprise 33% if all islet-cell neoplasms Usually Malignant (85%) Usually present as large tumors in the head of the pancreas

Function of the pancreas

Digestive (exocrine) - Produce pancreatic juice Hormonal (endocrine) - Controls secretion of glucagon and insulin into the blood

Sonographic Pitfalls

Do not confuse the pancreatic duct for the splenic vessels. - Use color Doppler Do not confuse the pancreatic duct for the stomach walls layers. Make sure pancreatic tissue is located on both the anterior and posterior aspect of the duct.

Pancreatic Abscess

Fluid collection of the byproducts from an infectious process - Majority of pancreatitis patients develop abscess secondary to postoperative procedures. - May rise from a neighboring infection, such as a perforated peptic ulcer, acute appendicitis, or acute cholecystitis - Can spread throughout the abdomen and/or into the pelvis Sonographic Findings: - Hypoechoic mass - Poorly defined - Smooth irregular boarders - Usually contains internal echoes - Walls may become calcified

Normal pancreas size

Head < 3 cm Neck < 2.5 cm Body < 2.5 cm Tail < 2.0 cm

Cystic Fibrosis

Hereditary disease that causes excessive production of thick mucus by the endocrine glands. Sonographic Findings: ◦ Fatty replacement of the pancreas (hyperechoic) ◦ Calcifications ◦ Multiple cysts of varying sizes

Echotexture of the pancreas

Homogeneous Smooth to slightly lobular surface (islets of Langerhans)

Acute pancreatitis

Inflammation of the pancreas caused by inflamed acini cells releasing pancreatic enzymes into the surrounding tissues. Divided into 3 categories. - Mild: Absence of organ failure or systemic complications - Moderately severe: Transient organ failure and/or systemic complications - Severe: Persistent organ failure with systemic complications

Pancreatitis

Inflammation of the pancreas. - May be classified as acute or chronic Occurs when the pancreas becomes damaged and malfunctions as a result of increased secretion and/or blockage of ducts. - When this occurs, pancreatic tissue may be digested by its own enzymes.

Hormonal (endocrine) functions

Located in the islets of Langerhans in the pancreas. Specialized cells with the islets: Alpha - Produce glucagon - Causes stored glucose to be release into the blood stream Beta - Produce insulin - Causes glycogen formation from glucose in the liver - Most prevalent specialized cell Delta - Produce somatostatin - Inhibits the production of both insulin and glucagon

Insulinoma (B-Cell Tumor)

Most common functioning islet-cell tumor (60%) - Usually benign (90%) - Most frequent in patients 40 - 60 years old with hyperinsulinisum and hypoglycemia Sonographic Findings: - Small, well encapsulated, hypervascular - May contain calcifications

Adenocarcinoma

Most common primary neoplasm of the pancreas - Most patents are more than 60 years old - Rare before the age of 40 Usually malignant (90%) - 2-3 month survival time - 1-year survival rate = 8% - 5% of all cancer deaths Tends to metastasize to the liver, stomach, spleen, lungs, adrenal glands, and the lymph nodes. - 70% of tumors are located in the pancreatic head Can cause Courvoisier's sign: - Obstruction of the CBD - Hydrops of the GB - Jaundice patient - Palpable, non-tender GB

Chronic pancreatitis

Occurs when recurrent attacks of acute pancreatitis cause permanent structural damage - Associated with chronic alcoholism or biliary disease. - Patient may also have pseudocysts (25 - 40%), a dilated common bile duct, or thrombosis of the splenic vein with extension into the portal vein; increases risk of patient developing pancreatic cancer.

Digestive (exocrine) functions

Performed by the acini cells of the pancreas Produce up to 2 L of pancreatic juice per day: - Lipase - digests fats - Amylase - digests carbohydrates - Chymotrypsinogen, carboxypeptidase, trypsin - digest proteins - Nucleases - digest nucleic acids When chyme enters the duodenum, hormones are released that trigger the release of the pancreatic juices. Pancreatic juices enter the duodenum through the duct of Wirsung and through the ampulla of Vater.

Duct of Santorini

Secondary duct that drains the upper anterior head

Pseudocyst complications

Spontaneous rupture is the most common complication of a pancreatic pseudocyst (5% of patients) - Pancreatic ascites develops - Mortality rate is 50%

Autosomal Dominant Polycystic Disease

◦ Characterized by multiple small cysts in the kidney, liver, and rarely the pancreas ◦ Vary from microscopic to several centimeters in diameter

Four anatomical areas of the pancreas:

◦ Head ◦ Neck ◦ Body ◦ Tail

Von Hippel-Lindau Syndrome

◦ Inherited disorder characterized by the formation of the multiple tumors and cysts in the kidneys, pancreas, and GI tract, tumors may be malignant ◦ Increased risk of developing pancreatic CA (pancreatic neuroendocrine tumors) ◦ Most frequently appears in young adulthood

Duct of Wirsung

◦ Primary duct, extending the entire length of the gland ◦ Receives tributaries from lobules at right angles and enters the duodenum with the common bile duct at the ampulla of Vater (guarded by the sphincter of Oddi)

Cystic Pancreatic Neoplasms

◦ Serous Cystic Tumors ◦ Mucinous Cystic Neoplasms ◦ Intraductal Papillary Mucinous Neoplasms