Spleen and Pancreas

Question 1

What are the complications of acute pancreatitis?

Answer 1

Complications of acute pancreatitis may be inflammatory, infectious, or vascular.

• A pancreatic pseudocyst is usually detectable by ultrasound, although the full extent of large pseudocysts can be difficult to determine by ultrasound alone.
• Infectious complications of acute pancreatitis include peripancreatic abscess, infected pseudocyst, and infected pancreatic necrosis.
• The two most important vascular complications of pancreatitis are splenic vein thrombosis and splenic artery pseudoaneurysm, both of which can be characterized by Doppler ultrasound.

Question 2

What are the ultrasound findings of acute pancreatitis?

Answer 2

• Usually, the pancreas appears normal in acute pancreatitis. The pancreas may be diffusely enlarged and relatively hypoechoic due to edema. more severe inflammation may cause the normally hypoechoic pancreas to become isoechoic to the liver.

Question 3

What are the US findings of chronic pancreatitis?

Answer 3

• The classic ultrasound appearance of chronic pancreatitis is an atrophied gland, with diffuse calcifications and dilated and beaded distal pancreatic duct.
• Calculi within the pancreatic duct may also be seen.

Question 4

What are the pancreatic neuroendocrine tumors?

Answer 4

Question 5

Pancreatic Adenocarinoma

Epidemiology? US findings? What is the double duct sign?

Answer 5

• Pancreatic adenocarcinoma is the most common pancreatic tumor and is typically seen in older males.
• Small tumors are hypoechoic, while larger masses may be more heterogeneous. It can be difficult to identify the tumor extent on ultrasound because of infiltrative margins and invasion of the tumor into pancreatic parenchyma and adjacent structures.
• The most common location for a tumor to arise is the pancreatic head, where the mass often presents with ductal obstruction. The double duct sign represents dilation of both the pancreatic and common bile ducts caused by malignant obstruction.

Question 6

What are the cystic pancreatic neoplasms?

Answer 6

• Cystic pancreatic neoplasms are a diverse group of unrelated pancreatic tumors that may appear similar by ultrasound.
• Serous cystadenoma is a benign tumor seen in older females, consisting of multiple tiny cysts. A characteristic calcified scar is not often seen but is very specific when present.
• Mucinous cystic neoplasm has malignant potential and is usually seen in middle-aged females. Compared to serous cystadenoma, the cysts are larger in size. The mucin can generate numerous fine echoes.
• Intraductal papillary mucinous neoplasm (IPMN) is a neoplasm of variable and controversial natural history that communicates with either the main pancreatic duct or branch ducts. demonstration of the ductal communication can be difficult by ultrasound.

Question 7

What is the most common subtype of lymphoma to affect the pancreas?

What is it almost always associated with?

Typical US appearance?

Answer 7

• B-cell lymphoma is the most common subtype of lymphoma to affect the pancreas, and is almost always associated with adenopathy and multi-organ involvement by the time the pancreas is involved.
• The typical ultrasound appearance of pancreatic lymphoma is a diffusely enlarged, hypoechoic gland.

Question 8

Pancreatic Endocrine Tumors

• Functioning vs nonfunctioning tumors
• Most common pancreatic endocrine tumor
  
  • US findings?

Answer 8

• Tumors arising from the neuroendocrine cells of the pancreas may be either functioning or nonfunctioning.
• Functioning tumors are usually symptomatic, small at diagnosis, and identified through biochemical testing. In contrast, nonfunctioning tumors.

Question 9

What is the second most common pancreatic endocrine tumor?

What is usually present at the time of diagnosis?

Answer 9

• Gastrinomas are the second most common pancreatic endocrine tumors.
• Liver metastases are present at the time of diagnosis in 60% of patients.

Question 10

Name the four types of pancreatic neoplasms.

Answer 10

1. Pancreatic adenoCA
2. Cystic pancreatic neoplasms
   
   • Serous cystadenoma
   • Mucinous cystic neoplasm
   • Intraductal papillary mucinous neoplasm (IPMN)
3. Pancreatic PNETs
   
   • Insulinoma, gastrinoma, glucagonoma, VIPoma, somatostatinoma
4. Pancreatic lymphoma

Question 11

Patterns of Disease:

Splenic Calcification

Answer 11

• Calcified splenic artery aneurysm.
• Hematoma.
• Splenic infarct
• Granulomatous disease: Calcifications may be scattered or diffuse

Question 12

Patterns of Disease:

Cystic Splenic Lesion

Answer 12

Color Doppler should always be used to exclude a vascular etiology

• Splenic artery aneurysm or pseudoaneurysm.
• Hematoma.
• Abscess.
• Pancreatic pseudocyst.

Question 13

Patterns of Disease:

Echogenic Splenic Lesions

Answer 13

• Hemangioma (can also be hypoechoic).
• Hamartoma.
• Lymphangioma.

Question 14

Patterns of Disease:

Hypoechoic Splenic Lesion

Answer 14

• Laceration (in the setting of trauma).
• Abscess.
• Lymphoma.
• Sarcoidosis.
• Metastasis.
• Infarct (tends to be peripheral).
• Extramedullary hematopoiesis.

Question 15

Patterns of Disease:

Splenomegaly

What measurement defines splenomegaly?

Answer 15

• Mild to moderate splenomegaly:
  
  • Portal hypertension (most common).
  • Infection.
  • AIDS.
• Moderate to marked splenomegaly:
  
  • Leukemia/lymphoma.
  • Infectious mononucleosis.
• Massive splenomegaly:
  
  • Myelofibrosis.

Question 16

Acute pancreatitis US appearance

Answer 16

• Usually, the pancreas appears normal in acute pancreatitis. The pancreas may be diffusely enlarged and relatively hypoechoic due to edema. More severe inflammation may cause the normally hypoechoic pancreas to become isoechoic to the liver.