Chapter 27 - Pancreas and Spleen (CHERI NOTES) Flashcards
_____ (___ test)increases pancreatic secretions and improves visualization of the pancreatic duct.(p.720)
SECRETIN administration during MRCP (Secretin test)
_____ provides excellent visualization of the lumen of the pancreatic duct; which is usually affected by any mass lesion of the pancreas (p.720)
Endoscopic retrograde cholangiopancreatography (ERCP)
- This procedure is performed by endoscopic cannulation of the bile and the pancreatic ducts followed by injection of a contrast agent and radiography.
TRUE OR FALSE.
Acute pancreatitis is generally diagnosed clinically. (p.720)
TRUE
Because the pancreas lacks a ____; the pancreatic juices
have ready access to the surrounding tissues. (p.720-721)
CAPSULE
- pancreatic enzymes digest fascial layers; spreading the inflammatory process to multiple anatomic compartments.
Three imaging abnormalities that may that may be seen in the pancreas (p.721)
- Focal or diffuse parenchymal enlargement
- changes in density due to edema
- indistinctness of the margins of the gland due to inflammation.
- abnormalities in the peripancreatic tissues include stranding densities in the fat with indisctinctness of the fat planes and thickening of affected
fascial planes.
_____ is a common congenital variant of pancreatic anatomy
that serves as a predisposition to pancreatitis. (p.721)
- the ventral and dorsal ductal systems of the pancreas fail to fuse.
- major portion of the pancreatic secretions from the body and tail drain through the dorsal pancreatic duct (Santorini) into the minor papilla;
- minor portion of pancreatic secretions from the head and uncinate process (ventral duct of Wirsung) drain into the duodenum through the major papilla in association with the common bile duct. (p.722)
PANCREAS DIVISUM
TRUE OR FALSE.
Relative obstruction at the minor papilla results in pancreatitis in 5% to 15% of patients with pancreas divisum. (p.722)
TRUE
- PANCREAS DIVISUM is found in 6% of the general population
- in 10% to 20% of patients with a history of acute recurrent pancreatitis.
_____ is caused by recurrent and prolonged bouts of acute pancreatitis that cause parenchymal atrophy and progressive fibrosis. (p.723)
CHRONIC PANCREATITIS
- both the exocrine and the endocrine functions of the pancreas may be impaired.
The most common causes of chronic pancreatitis are \_\_\_\_ (70%) and (20%). (p.723)
ALCOHOL ABUSE (70%) and BILIARY STONE DISEASE (20%).
- many of the remaining patients may have autoimmune pancreatitis
that responds to steroid therapy.
7 morphologic changes of chronic pancreatitis. (p.723)
- Dilation of the pancreatic duct (70% to 90% of cases); usually in a beaded pattern
- decrease in visible pancreatic tissue because of atrophy
- calcifications (40% to 50% of cases)in the pancreatic parenchyma.
- fluid collections that are both intrapancreatic and extrapancreatic
- focal mass-like enlargement of the pancreas owing to benign inflammation and fibrosis
- stricture of the biliary duct because of fibrosis or mass in the pancreatic head resulting in proximal bile duct dilatation
- fascial thickening and chronic inflammatory changes in the surrounding tissues.
____ is a unique form of chronic pancreatitis caused by autoimmune system disease that involves the pancreas; kidneys; bile ducts and retroperitoneum (p.723)
AUTOIMMUNE PANCREATITIS
(Lymphoplasmacytic Sclerosing Pancreatitis)
- periductal infiltration by lymphocytes and plasma cells results in
mass-like enlargement of the pancreas closely simulating adenocarcinoma - differentiation is important because autoimmune pancreatitis is effectively treated with oral steroids (p.723)
DIAGNOSIS ?
Imaging findings include:
1. Diffuse or focal swelling of the pancreas with
characteristic tight halo of edema
2. extensive peripancreatic stranding and edema are absent
3. diffuse or segmental narrowing of the pancreatic duct or the common bile duct
4. absence of dilatation of the pancreatic duct and absence of parenchymal atrophy proximal to the pancreatic mass (typically present with adenoCA)
5. pseudocysts and parenchymal calcifications are typically absent
6. peripancreatic blood vessels are usually not involved
7. the kidneys are involved in one-third cases of cases
8. serum IgG4 is often elevated
(p.724)
AUTOIMMUNE PANCREATITIS
(Lymphoplasmacytic Sclerosing Pancreatitis)
- imaging findings normalize following steroid treatment
____ is an uncommon form of chronic pancreatitis that may also mimic adenoCA
- fibrosis in the groove between the head of the pancreas; the descending duodenum; and the common bile duct produces an inflammatory mass that obstructs the common bile duct. (p.724)
GROOVE PANCREATITIS
- sheet-like mass in the pancreaticoduodenal groove
- atrophy and fibrotic changes in the pancreatic head
- small cysts along the wall of the duodenum
- duodenal wall thickening and luminal narrowing
- tapering stenosis of the common bile duct and pancreatic ducts
- widening of the space between the distal ducts and the wall of the duodenum
DIAGNOSIS ? It accounts for 3% of all cancers and second only to colorectal cancer as the most common digestive tract malignancy.
- the average survival time of a patient with this disease is only 5 to 8 months (p. 724)
PANCREATIC ADENOCARCINOMA (DUCTAL CARCINOMA)
- AdenoCA appears as a hypodense mass distorting the contour of the gland
- associated findings include obstruction of the common bile duct and the pancreatic duct and atrophy of pancreatic tissue beyond the tumor
Pancreatic AdenoCA METASTASES commonly goes to___ nodes; ___ and the _____ cavity. (p.724)
- REGIONAL nodes
- LIVER
- PERITONEAL cavity
3 signs of RESECTABILITY of Pancreatic AdenoCA.(p.724)
- Isolated pancreatic mass with or without dilatation
of the bile or pancreatic ducts - no extrapancreatic disease
- no encasement of celiac axis or superior mesenteric artery
3 signs of POTENTIAL resectability of Pancreatic AdenoCA
p. 724
- Absence of involvement of the celiac axis or the
superior mesenteric artery - regional nodes may be involved
- limited peripancreatic extension of tumor may be present
3 signs of UNRESECTABILITY of Pancreatic AdenoCA
p.724-725
- Encasement of the celiac axis or the SMA
- Occlusion of the superior mesenteric or portal vein
without a technical option for reconstruction - Liver; peritoneal; lung;or any other distant metastases.
3 evidence of ARTERIAL ENCASEMENT that indicate
unresectability in PANCREATIC ADENOCA (p.725)
- Tumor abutting greater than 180 degree of the circumference of the artery
- Tumor abutment focally narrowing the artery
- Occlusion of the artery by tumor
Tumor reccurence ff the Whipple procedure is best detected with ____ . (p.725)
MULTIDETECTOR CT
- MRCP defines ductal anatomy with dilatation proximal to the
stricturing tumor - MRA and MRV are excellent in identifying vascular involvement
by tumor
_____ pancreatitis may produce a mass that mimics pancreas carcinoma. (p.725)
CHRONIC PANCREATITIS
Beaded dilatation of the pancreatic duct is characteristic of _____ whereas smooth ductal dilatation is most frequent with ___.(p.725)
CHRONIC PANCREATITIS; CARCINOMA
- calcifications within the mass are common with
CHRONIC PANCREATITIS and are very rare with ADENOCARCINOMA - islet cell tumors more commonly contain calcifications
___ tumors may be functioning producing hormones resulting in
distinct clinical syndromes or may be nonfunctional and grow to large size before presenting cinically. (p.725)
NEUROENDOCRINE (ISLET CELL) tumors
Neuroendocrine tumor where patients present with episodic hypoglycemia (p.725)
INSULINOMAs
Neuroendocrine tumor where patients present with peptic ulcers; diarrhea caused by gastric hypersecretion;or Zollinger-Ellison syndrome.(p.725)
GASTRINOMAs
Islet cell tumor which present with diabetes mellitus and painful
glossitis (p.725)
GLUCAGONOMA
Islet cell tumor which present with diabetes and steatorrhea
(p.725)
SOMASTATINOMA
Islet cell tumor which present with massive watery diarrhea.
(p.725)
VIPoma
Arrange these islet tumors according to their malignant
potential from lowest to highest. (p.725)
GASTRINOMA; INSULINOMA; GLUCAGONOMA
INSULINOMA< GASTRINOMA
Functionally islet cell tumors are usually ____ cm in size and require strict attention to technique for accurate preoperative identification.(p.725)
less than 3 cm in size
- most small neudoendocrine tumors cannot be
identified on precontrast CT - because the lesions tend to be hypervascular; bolus contrast administration during rapid; thin-slice; MDCT scanning through the
pancreatic bed offers the best chance of lesion visualization. - the tumor stands out as an enhancing nodule
within the pancreas
Imaging appearance of ISLET CELL tumors in MR? and US?
p.725
MR:
- T1WI: low signal
- T2WI: high signal
- Postcontrast: homogeneously hyperintense
ULTRASOUND:
- hypoechoic masses within the pancreas
TRUE OR FALSE.
Up to 80% of pancreatic nonfunctioning tumors are malignant. (p.725)
TRUE
- non-functioning islet cell tumors tend to be much larger;
6 to 20 cm in diameter - imaging findings include coarse calcifications; cystic degeneration;
necrosis; local and vascular invasion and metastases
MR findings in pancreatic non-functioning tumors
(p.725)
T1W? T2W? And DYNAMIC
POST-CONTRAST IMAGES ?
HETEROGENEOUS MASSES
are generally:
T1WI: generally low signal
T2WI: heterogeneous high signal in cystic and necrotic areas
Dynamic Postcontrast images: heterogeneously hyperenhancing
Metastases to the pancreas are most frequent with
____ carcinoma and _____ carcinoma. (p.725)
RENAL CELL Carcinoma; BRONCHOGENIC Carcinoma
Three possible imaging appearances of pancreatic metastases
p.725-726
- Solitary; well-defined; heterogeneously-enhancing mass
- Diffuse heterogeneous enlargement of the pancreas
- Multiple nodules
TRUE OR FALSE.
Metastases to the pancreas have no predilection for any particular portion of the pancreas. (p.726)
TRUE
MR imaging appearance of metastases to the pancreas;including melanoma mets. (p.726)
T1WI? T2WI? (mets to the pancreas)
T1WI? (Melanoma mets)
METS TO THE PANCREAS
T1W: low signal
T2W: high signal
MELANOMA METS
T1W: hyperintense; because of the paramagnetic properties of melanin
____ may involve the pancreas as a primary site (rare) or by direct extension from disease in the retroperitoneum. (p.726)
LYMPHOMA
- on CT: most lesions are homogeneous; of lower attenuation than muscle; and show limited enhancement.
- lesions can be a localized; well-defined mass or infiltrating diffusely enlarging or replacing the gland.
- attenuation may be so low as to appear cystic
Fatty lesions of the pancreas include __; ___; ____; and ____.
(p.726)
- DIFFUSE FATTY INFILTRATION
- FOCAL FATTY INFILTRATION
- FOCAL FATTY SPARING
- LIPOMA
DIAGNOSIS?
Fat infiltrates between the lobules of pancreatic parenchyma.
- associated with aging and obesity and is seen with pancreatic atrophy. (p.726)
DIFFUSE FATTY INFILTRATION OF THE PANCREAS
TRUE OR FALSE. Focal fatty sparing in diffuse infiltration may simulate a pancreatic mass; especially when it involves the head or uncinate process. (p.726)
TRUE
- focal fatty infiltration may
involve any portion of the
pancreas. (p.726)
___ are rare; usually solitary; fat-density
pancreatic masses that are
usually incidental findings but may occasionally
obstruct the pancreatic
or the bile ducts. (p.726)
LIPOMAS
DIAGNOSIS? The pancreas in teenage and adult patients is commonly entirely replaced by fat in association with exocrine insufficiency.
- now commonly seen in adults as treatment
has continued to improve.
(p.726)
CYSTIC FIBROSIS
\_\_\_\_ refers to the unsual occurrence of macrocysts of varying size distributed througout the pancreas in patients with cystic fibrosis. (p.726)
PANCREATIC CYSTOSIS
- the cysts are true cysts developing from functional remnants of pancreatic ducts. - additional findings: acute pancreatitis and calcifications in the pancreas
____ include primary cystic tumors
(5% to 10% of cystic lesions) and
cystic degeneration of solid tumors
(p.726)
CYSTIC NEOPLASMS
____ rarely arise in the pancreas
and usually have characteristic hair;
fat; calcifications and cystic and
solid components. (p. 726)
CYSTIC TERATOMAS
___ is the optimal modality for
imaging characterizations of cystic
lesions. (p. 726)
MR
______ resulting from pancreatitis are
the most common pancreatic cystic
lesions representing up to 85% to
90% of cystic lesions. (p.726)
- most of them are unilocular fluid
collections confined by a fibrous
wall that does not contain epithelium
(p.726)
PSEUDOCYSTS
DIAGNOSIS/ Imaging findings include: 1. fluid density unilocular cyst associated with findings of acute or chronic pancreatitis 2. complex cystic mass with internal hemorrhage; infection or gas 3. most are round or oval with a thin or thick wall that may enhance; however; cyst contents do not enhance 4. septations and lobulated contours are unusual and more often associated with serous cystadenoma 5. serial imaging usually shows involution of the lesion. (p.726)
PSEUDOCYSTS
___ must be considered in any
patient with cystic pancreatic lesion
andd fever. (p.726)
ABSCESS
- most abscesses have indistinct
walls and contain fluid and debris
The presence of ____ within the
cystic mass is a strong evidence
for abscess. (p. 726)
GAS BUBBLES
___ cystadenomas are benign tumors
that do not require treatment. (p.726)
- tumors occur most commonly in women(esp . >60 yrs) and are distributed uniformly throughout the head; body and tail of the pancreas. (p.726)
SEROUS cystadenomas
- these lesions are associated
with von Hippel-Lindau syndrome
Give 3 major imaging appearances of
SEROUS CYSTADENOMAS. (p.726-727)
1. the most common is the honeycomb microcysts (microcyst adenoma) with innumberable small cysts 1 mm to to 2 cm in size 2. a macrocystic form with larger cysts is seen in 10% overlapping the appearance of mucinous cystadenoma 3. innumerable tiny cysts may make the lesion appear solid.
TRUE OR FALSE.
A central stellate scar that may
calcify is a highly diagnostic feature
of SEROUS CYSTADENOMA. (p.727)
TRUE
- SEROUS CYSTADENOMA do not communicate with the pancreatic duct - diagnosis is confirmed by aspiration of clear fluid without mucin
____ neoplasm occurs most
commonly in the tail and
usually in women. (p.727)
- lesions show pathologic progression
from benign adenoma to low-grade
malignancy to invasive carcinoma
MUCINOUS CYSTIC NEOPLASM
- lesions hows pathologic progression from benign adenoma to low-grade malignancy to invasive carcinoma. - imaging shows a macrocystic lesion (>2cm) in the pancreatic tail that is unilocular or multilocular with few compartments. - metastases to the liver tend to be cystic
TRUE OR FALSE. Peripheral eggshell calcification is uncommon but highly specific finding in SEROUS CYSTADENOMA. (p.727)
TRUE
_____ neoplasms are mucinous
tumors with malignant potential
deserving surgical resection. (p.727)
INTRADUCTAL PAPILLARY MUCINOUS NEOPLASMS (IPMN)
The lesion may affect the main pancreatic duct (\_\_\_\_\_ IPMN) resulting in marked dilatation resulting from continuing mucin production and progressive atrophy of the pancreatic parenchyma resulting from obstruction. (p.727)
MAIN DUCT IPMN
- papillary solid tumor excrescences may be seen within the dilated duct. - only a thin rim of atrophic pancreatic parenchyma may be present
Alternatively one or more branch ducts may be affected (\_\_\_\_ IPMN). - a focal group of small cysts (1 to 2 cm diameter) that intercommunicate through dilated branch ducts. (p.727)
BRANCH DUCT IPMN
BRANCH DUCT IPMN are most
common in the ____. (p.727)
UNCINATE PROCESS
____ IPMN carry a higher risk of
carcinoma. (p.727)
MAIN DUCT IPMN
6 features that suggest the presence
of carcinoma in IPMN: (p. 727)
1. Dilatation of the main pancreatic duct greater than 7 to 15 mm 2. multiple mural nodules greater than 3 to 10 mm in size 3. tumor greater than 2 to 6 cm 4. calcified intraluminal contents 5. associated dilatation of the common bile duct 6. peripancreatic lymph node enlargement
\_\_\_\_\_ tumor of the pancreas is a rare; usually benign; neoplasm presents as a large encapsulated mass with a mixture of cystic; hemorrhagic; and solid components. (p.727)
SOLID PSEUDOPAPILLARY TUMOR
- it occurs most frequently in young women - approx. 15% demonstrate low-grade malignant elements. - patients are often asymptomatic even though the lesions may exceed 20 cm in size. - these lesions most closely resemble neuroendocrine tumors
TRUE OF FALSE. Cystic change in adenoCA is usually the result of necrosis; hemorrhage ; or formation of pseudocysts adjacent to the neoplasm. (p.728)
TRUE
___ diverticula filled with
fluid may mimic a cystic
pancreatictumor or an
abscess. (p.728)
DUODENAL diverticula
____ are common incidental
findings in the pancreas
demonstrated with high
sensitivity by MR. (p.728)
TINY SIMPLE CYSTS
\_\_ and \_\_ remain the major techniques used to image the splenic parenchyma although with new techniques MR plays an increasing role. (p.728)
CT and US
- Gadolinium enhancement
improves the specificity of spleen
MR
\_\_\_\_\_ scanning images both the liver and the spleen and can be used to confirm the presence of functioning splenic tissue; which is important in the diagnosis of splenosis. (p.728)
TECHNETIUM SULFUR COLLOID
RADIONUCLIDE scanning images
Body’s largest lymphoid
organ. (p.728)
SPLEEN
- site of blood formation in the fetus
- no hematopoietic activity
in the normal adult spleen - sequesters abnormal and aged
red and white blood cells and
platelets and serves as reservoir
for red blood cells.
Location of the spleen
p.728
left upper quadrant of the
abdomen just below the
diaphragm; posterior and lateral
to the stomach.
Spleen size varies with __;
___ and ___. (p.728)
AGE; NUTRITION AND HYDRATION
TRUE OF FALSE.
The spleen is relatively large
in children; reaching adult
size by 15 years. (p.728)
TRUE
The average spleen dimensions in adults are \_\_ cm in length; \_\_ cm in width; and \_\_\_ in thickness. (p.728)
12 cm in length; 7 cm in width;
3 to 4 cm in thickness
- in older adults; the spleen
progressively decreases in size
with age.
TRUE OR FALSE. Splenic arteries are end arteries without anastomoses or collateral supply. (p.728)
TRUE
- occlusion of the splenic artery
or its branches produces
infarction
SPLEEN
On US? On Noncontrast CT?
On MR?
On US: demonstrates a midlevel homogeneous echo pattern for the splenic parenchyma on NON-CONTRAST CT: the normal spleen density is less than or equal to the density of the normal liver. On MR: the spleen signal intensity is lower than hepatic parenchyma on T1WI and higher than liver parenchyma on T2WI
Following IV contrast injection; the enhancement pattern of the spleen reflects the normal rapid direct circulation of the \_\_\_\_; which functions to clear aging and damaged blood cells. (p.728)
RED PULP
During arterial phase; splenic contrast enhancement appears alternating bands of high and low density; the \_\_ enhancement pattern. (p.728)
ARCIFORM enhancement
pattern
- delayed post-contrast images
show homogeneous enhancement
of the splenic parenchyma
Transient pseudomasses
of the spleen may be formed
during the ___ phase on
postcontrast CT and MR. (p.728)
ARCIFORM enhancement
pattern
- diffuse liver disease is associated
with more prominent splenic
pseudomasses during early enhancement.
TRUE OR FALSE. Lobulations or clefts in the splenic contour are common and must not be mistaken for masses or splenic fractures. (p.728)
TRUE
\_\_\_\_ are found in 10% to 16% of normal individuals. These appear as round masses; 1 to 3 cm in size and of the same texture as normal splenic parenchyma. (p.728)
ACCESSORY SPLEENS
- may be single or multiple and are usually located near the splenic hilum - Technetium sulfur colloid radionuclide scans can be used to confirm suspected accessory spleens as functioning splenic tissue.
\_\_\_\_ is the term applied to a normal spleen positioned outside of its normal location in the left upper quadrant. (p.729)
WANDERING SPLEEN
- laxity of the splenic ligaments; commonly found in association with abnormalities of intestinal rotation; allows the spleen to be positioned anywhere in the abdominal cavity.
TRUE OR FALSE. A wandering spleen may be present as a palpable abdominal mass; although most cause no symptoms. (p.729)
TRUE
- because of lax ligament;
the spleen may rotate and torse
causing acute or recurrent
abdominal pain.
How is a wandering spleen
diagnosed? (p.729)
The diagnosis is made by recognizing the normal shape and tissue texture of the spleen; noting the absence of normal spleen in the left upper abdomen; and by identifying the blood supply from splenic vessels.
- radionuclide scans confirm
functioning splenic tissue
\_\_\_ refers to multiple implants of ectopic splenic tissue that may occur after traumatic splenic rupture. (p.729)
SPLENOSIS
- Splenic tissue can implant anywhere in the abdominal cavity or even in the thorax if the diaphragm has been ruptured. - the tissue fragments enlarge over time and may simulate peritoneal metastases. - Splenosis complicates 40% to 60% of traumatic splenic injuries.
TRUE OR FALSE. After splenectomy; remaining accessory spleens or splenules resulting from traumatic peritoneal seeding of splenic tissue; may enlarge and resume the function of the resected spleen. (p.729)
TRUE
When the spleen is removed; bits of nuclear material; called \_\_\_\_\_; are routinely seen in red cells on peripheral blood smears. (p.729)
HOWELL-JOLLY BODIES
- Normal splenic tissue routinely
clears red blood cells containing
Howell-Jolly bodies from the
peripheral blood.
Disappearance of Howell-Jolly
bodies from peripheral blood
is a clinical sign of ___. (p.729)
SPLENIC REGENERATION
Imaging studies demonstrate single or multiple spleen-like masses in the abdominal cavity in patients with a history of \_\_\_. (p.729)
history of SPLENECTOMY
\_\_\_\_ is a rare congenital anomaly that features multiple small spleens; usually located in the right abdomen and associated with situs ambiguous. (p.729)
POLYSPLENIA
- Both lungs are two-lobed.
Most patients also have
cardiovascular anomalies.
\_\_\_\_\_ (\_\_\_\_ syndome) is the congenital absence of the spleen; found in association with bilateral right-sidedness; midline liver; and bilateral three-lobed lungs. (p.729)
ASPLENIA
(IVEMARK SYNDROME)
- major cardiac anomalies are
present in 50% of cases - most patients die before 1 year
of age.
TRUE OR FALSE. The diagnosis of splenic enlargement on imaging studies is usually made subjectively. (p.729)
TRUE
4 Imaging findings that
are suggestive of
SPLENOMEGALY. (p.729)
- enlarged spleen frequently
compress and displace adjacent organs;
especially the left kidney.
1. any spleen dimension greater than 14 cm 2. projection of the spleen ventral to the anterior axillary line 3. inferior spleen tip extending more caudally than the inferior liver tip 4. inferior spleen tip extending below the lower pole of the left kidney.
TRUE OR FALSE. MR offers NO significant benefit to the differential diagnosis of splenomegaly. (p.730)
TRUE
Mild to moderate
splenomegaly is seen with
____. (p.730)
- Portal Hypertension
- AIDS
- Storage diseases
- Collagen Vascular Disorders
- Infection
More marked splenomegaly
is usually associated with
____. (p.730)
- LYMPHOMA
- LEUKEMIA
- INFECTIOUS MONONUCLEOSIS
- HEMOLYTIC ANEMIA
- MYELOFIBROSIS
____ is the most common
malignant tumor involving
the spleen. (p.730)
LYMPHOMA
- commonly; the spleen involved with diffuse infiltrative lymphoma appears normal on all imaging studies. - CT is only 65% sensitive in demonstrating splenic involvement with lymphoma.
5 Patterns of lymphoma
involvement of the spleen
on imaging studies. (p.730)
- Diffuse Splenomegaly
- Multiple masses of varying
sizes - Miliary nodules resembling
microabscesses - Large solitary mass
- Direct invasion from adjacent
lymphomatous nodes
TRUE OR FALSE. ADENOPATHY is frequently evident elsewhere in the abdomen when the spleen is involved with lymphoma. (p.730)
TRUE
- is a common predisposing
condition for splenic infarction
TRUE OR FALSE. Most splenic metastases are microscopic and are not detectedby imaging studies. (p.730)
TRUE
- on MR; metastases are
T1WI: low intensity
T2WI: high intensity
- the increased signal intensity of the lesions parallel the increased signal intensity of the normal splenic parenchyma on T2WI; and the lesions may not be evident.
6 most common tumors
to the metastasize to the
spleen are ___. (p.730)
- Malignant Melanoma
- Lung CA
- Breast CA
- Ovarian CA
- Prostatic CA
- Gastric CA
TRUE OR FALSE. Contrast enhancement is recommended for both CT and MR demonstration of metastases. (p.730)
TRUE
- Calcification is rare in splenic
metastases - Melanoma metastases commonly
appear cystic.
Splenic infarction is
produced by ___. (730)
OCCLUSION OF THE MAIN OR
BRANCH SPLENIC ARTERIES
5 causes of splenic infarction.
p.730
1. Emboli (owing to endocarditis; atherosclerotic plaques; or cardiac valve thrombi) 2. Sickle cell disease 3. Pancreatitis 4. Pancreatic tumors 5. Arteritis
- additional predisposing
conditions include
myeloproliferative disorders;
hemolytic anemias and sepsis.
Splenic infacts
typically appear
as _____ in the splenic
parenchyma. (p.730)
WEDGE-SHAPED DEFECTS
- multiple infarcts may fuse; however; and the wedge shape may be lost. - KEY FINDING: extension of the abnormal parenchymal zone to an intact splenic capsule
3 complications of splenic
infarctions. (p.731)
- Subcapsular hematomas
- Infection
- Splenic rupture with
hemoperitoneum
\_\_\_\_\_ ( as called \_\_\_\_ ) are small hemorrhages in the spleen caused by portal hypertension and resulting in foci of hemosiderin deposition.
GAMMA GANDY BODIES
(also called SIDEROTIC NODULES)
- best seen on MR as multiple
small low-intensity nodules on T1WI
and T2WI
Signal intensity of
GAMMA GANDY BODIES
is LOW because of ___.
(p.731)
signal intensity is LOW because of
HEMOSIDERIN content.
- THEY DO NOT ENHANCE.
____ is the most common
primary neoplasm of the
spleen; found in 14% of
patients on autopsy series.
- the tumor consists of
vascular channels of varying
size lined by a single layer of
endothelium. (p.731)
HEMANGIOMA
- US: well-defined hyperechoic mass
- CT: the lesion may appear solid
and may have central punctate or
peripheral curvilinear calcification - MR: the lesion is low in signal
intensity on T1WI and high in
signal intensity on T2WI - the contrast enhancement
pattern is variable
TRUE OR FALSE. The nodular enhancement form the periphery described for liver hemangiomas is not often seen with splenic hemangiomas. (p.731)
TRUE
_____ is very rare but is still
the most common malignancy
arising in the spleen. (p.731)
- tumor is aggressive usually
presenting with widespread
metastases; esp. to the liver.
ANGIOSARCOMA
- imaging studies demonstrate multiple well-defined enhancing nodules or diffuse spleen abnormality - patient thorotrast exposure are at increased risk
___ are false splenic cysts
that lack an epithelial lining.
(p.731)
POSTTRAUMATIC CYSTS
- generally have thick walls and septations that commonly become calcified (30% to 40%) - the internal fluid may be complex owing to blood products; cholesterol crystals or cellular debris
_____ account for 80% of all
splenic cysts. (p.731)
POSTTRAUMATIC CYSTS
- posttraumatic cysts result
from previous hemorrhage;
infarction or infection
___ cysts are true epithelial-
lined cysts that are probably
developmental in origin.
(p.731)
EPIDERMOID CYSTS
- similar apperance to
posttraumatic cysts but less
frequently have calcification
in their walls (5%)
TRUE OR FALSE.
Pancreatic pseudocysts extend beneath the splenic capsule by tracking along the pancreatic tail to the splenic hilum.
TRUE
- Splenic subcapsular pancreatic fluid collections develop in 1%
to 5% of patients with pancreatitis - internal debris and hemorrhage are commonly present
- imaging studies demonstrate associated findings of pancreatitis
TRUE OR FALSE.
Bacterial abscesses occur most commonly in spleens that are already diseased. (p.732)
TRUE
- they present with vague symptoms but have a high mortality when
left untreated. - they result from: hematogeneous spread of infection (75%);
trauma (15%) or infarction (10%)
Splenic Abscesses appear as ___. (p.732)
SINGLE or MULTIPLE LOW-DENSITY MASSES WITH
ILL-DEFINED THICK WALLS
- US demonstrates internal echoes resulting from inflammatory
debris - MR T1WI: low signal intensity
- MR T2WI: high signal intensity
- may contain gas or demonstrate air-fluid levels
- perisplenic fluid collections and left pleural effusions are common
- image-guided aspiration confirms the diagnosis
- Treatment is by catheter drainage or splenectomy
Splenic _____ are found in patients with compromised
immune systems attributable to AIDS; organ transplantation; lymphoma or leukemia. (p.732)
MICROABSCESSES
- causes of microabscesses: fungi; TB; Pneumocystis carinii; histoplasmosis and CMV
DIAGNOSIS?
Imaging studies demonstrate multiple small defects in the
spleen; usually 5 to 10 mm up to 20 mm; in size.(p.732)
MICROABSCESSES
Hydatid cysts of the spleen is found only in ___ % of patients with hydatid disease.(p.732)
2%
- hydatid cysts are usually also present in the liver or lung
- the lesion consists of spherical Mother Cysts that contain smaller
daughter cysts and have internal septations and debris representing
hydatid sand. - ring-like calcification in the wall
are usually prominent in the chronic stage
Most common finding in patients with AIDS.(p.732)
SPLENOMEGALY ASSOCIATED WITH GENERALIZED LYMPHOID HYPERPLASIA
- focal lesions in the spleen are usually caused by oppurtunistic
infections such as atypical mycobacterium; Candida or Pneumocystis jiroveci. - P. jiroveci infection may cause multiple splenic calcifications
TRUE OR FALSE.
AIDS associated lymphoma and Kaposi sarcoma may also
cause single or multiple solid-appearing lesions in the spleen.
TRUE
__ offers an excellent invasive method of imaging the pancreatic duct as well as the biliary system. (p.720)
MR Cholangiopancreatography (MRCP)
