1.
INTRODUCTION
1.1
Definition
Of Pancreatic Carcinoma
From the pancreas (2011), the author noted that the pancreas is an organ
located deep in the abdomen between the stomach and the spine. The pancreas is about 6 inches long. The largest part of the pancreas is the head,
the middle section is the body, and the thinnest part is the tail.
The function of the pancreas is to
release enzymes into the intestines that help the body absorb foods (pancreatic carcinoma, 2011). The pancreas also makes insulin and other
hormones. These hormones enter the bloodstream
and travel all over the body. They help
the body use or store the energy that comes from food (the pancreas, 2011).
Pancreatic carcinoma is cancer of
the pancreas which is a malignant neoplasm originating from transformed cells
arising in tissues forming the pancreas (pancreatic
cancer, 2012). From what is pancreatic cancer? Pancreatic cancer
and causes (2012), the author stated that pancreatic cancer occurs when
there is uncontrolled cell growth begins in the pancreas. These abnormal cells continue dividing and
form masses of tissue called tumors. A
benign tumor stays in one spot and demonstrates just a limited growth. Malignant tumors form when the cancer cells
migrate to other parts of the body through the blood or lymph systems. It is said to have metastasized if a tumor successfully
spreads to other parts of the body and grow, invading and destroying other
healthy tissues (what is pancreatic
cancer? Pancreatic cancer and causes, 2012).
1.2
Etiology
Dragovich (2012) noted that pancreatic
cancers can arise from the exocrine and endocrine portions of the pancreas, but
95 percent of them develop from the exocrine portion, including the ductal
epithelium, acinar cells, connective tissue, and lymphatic tissue.
The exact cause of pancreatic cancer
in unknown (pancreatic cancer, 2012). There are some researchers wrote that
pancreatic cancer is caused by DNA mutations and also other risk factors. Some
of the risk factors include cigarette smoking, age, race, gender, religious
background, chronic pancreatitis, diabetes, obesity, diets, and genetics (what causes pancreatic cancer, 2012). Mostly researchers agree that pancreatic
cancer is slightly more common in women than in men. The risk of pancreatic
cancer increases with age and a small number of cases are related to genetic
syndromes that are passed down through families (pancreatic cancer, 2012).
1.3
Sign
and Symptoms
Nugent and Stuart (2012) noted in
their article, early symptoms for pancreatic cancer can be absent because it
often grows silently for month before it is discovered and the symptoms will
develop when the tumor grows large enough and press on other nearby structures
such as nerves, the intestines, and bile ducts.
When the tumor press on nerves, this will causes pain. While on intestines, the affects will be loss
of appetite, nausea, and weight loss and when the tumor press on bile ducts,
this will causes jaundice and can also cause loss of appetite and itching
(Nugent & Stuart, 2012).
However, from pancreatic cancer symptoms (2012), the author stated that symptoms
of pancreatic cancer depend on the cancer’s location within the pancreas. The author noted that pancreatic cancer in
the head of the pancreas is likely to cause symptoms such as weight loss,
jaundice, dark urine, light stool color, itching, nausea, vomiting, abdominal
pain, back pain, and enlarged lymph nodes in the neck but pancreatic cancer in
the body or tail of the pancreas usually causes belly or back pain and weight
loss.
1.4
Pathophysiology
Dragovich (2012) noted that
pancreatic cancer, usually first metastasizes to regional lymph nodes, then to
the liver, and less commonly, to the lungs. It can also directly invade
surrounding visceral organs such as duodenum, stomach, and colon. Other than that, it can metastasize to any
surface in the abdominal cavity via peritoneal spread. Ascites may result. Pancreatic cancer also may spread to the skin
as painful nodular metastases (Dragovich, 2012).
1.5
Treatment
Nugent
and Stuart (2012) noted that surgery may be recommended if a pancreatic cancer
is found at an early stage and is located only within or around the
pancreas. The author also noted that
surgery is the only treatment for pancreatic cancer. After patients recover from surgery, normally
six month of chemotherapy is recommended.
This treatment has proven to lower the risk of recurrent cancer (Nugent
& Stuart, 2012).
1.6
Prognosis
Nugent
and Stuart (2012) also mentioned in their article that only about 20 percent of
patients undergoing a surgery procedure for curable pancreatic cancer live five
years, others surviving on average less than two years. Nugent and Stuart (2012) added for patients
with incurable pancreatic cancer, survival is even shorter. With metastatic disease (stage IV), the average
survival is just over six months.
3. DISCUSSION
The
pancreas has a head with an uncinate process, a neck, a body and a tail
(Lumley, Craven, & Aitken, 1987). In
normal CT images of the pancreas, Ryan and McNicholas (1994) reported that the
tail is visible at the splenic hilum on the highest slices and the uncinate
process is the lowest part. Normal
thickness of the head is 2cm, the neck 0.5 – 1 cm and the body and tail 1 – 2
cm (Ryan & McNicholas, 1994). The
height of the head is very variable and may measure up to 8 cm and the body and
tail may measure 3 – 4 cm (Ryan & McNicholas, 1994). However, for this patient, the normal anatomy
area of the pancreas is altered by the large mass.
Radiologist,
Dr Asokan Raman Nair (personal communication, November 20, 2012) interpret that
there is a large mass arising from the tail of pancreas. Figure 14 shows first slice of CT images that
shows beginning of pancreatic mass. The
mass in this image only measure 2.0 x 3.1 cm.
The mass at the tail of the pancreas can be seen clearly at figure 16
measures 6.1 x 4.6 cm. Because of the
mass cover the whole tail of the pancreas, the normal structure of tail of the
pancreas cannot be seen. In the normal
anatomy images, the tail of pancreas is the narrowed left extremity and lies in
the lienorenal ligament (Lumley et al. 1987).
The tail lies with the splenic vessels between two layers of the
lienorenal ligament and reaches the hilus of the spleen (Lumley et al.
1987). Other than that, the radiologist
noted that this mass is predominantly cystic with thickened enhancing
walls. This can be seeing clearly in
figure 32. The attenuation value or
Hounsfield unit (HU) for the mass is approximately 15 to 25 and the enhancing
wall surrounded the mass is approximately 80.
According to Molteni (2011), HU for water is 0, blood is +40 and muscle
also +40. Clearly, the mass is cystic
like what radiologist reported and the thickened wall surrounded the mass
probably either blood or just muscle-like tissue.
The mass
from the tail of the pancreas extends to the body of the pancreas shows in
image 18 reported by radiologist. Here
it is measured 8.1 x 6.1 cm. He also
noted that large pancreatic mass at the body of the pancreas can be seen in
figure 29 which measured 11.8 x 7.6 cm. Like a tail, the body structure of the
pancreas also cannot be seen because of the mass. In normal radiograph of the pancreas, the
body is triangular in section and has anterior, inferior, and posterior
surfaces (Lumley et al. 1987). Lumley et
al. (1987) noted that its anterior surface is related to stomach and lesser
omentum, inferior surface is related to the duodenojejunal flexure and coils of
jejunum, and the transverse mesocolon is attached to the border between the
anterior and inferior surfaces. As shows
in figure 29, radiologist showed from right to left, the mass at the body lies
on the aorta, superior mesenteric artery, the left crus of the diaphragm, the
left renal gland, and anterior surface of the left kidney.
However,
radiologist reported that the pancreatic head is normal as shown in figure
32. Even though there is still large
mass at the body of the pancreas, the mass does not cover the head of the
pancreas. Other than that, in figure 38,
radiologist reported, uncinate process of the pancreas also appears
normal. In normal radiograph, the head
is the expanded right extremity of the gland bearing inferiorly an uncinate
process which passes to the left (Lumley et al. 1987). Just like in figure 32 where the radiologist reports
the normal appearance of the head, Lumley et al. (1987) also noted that
anteriorly from above downwards the head is covered by the pylorus, the
transverse colon, and coils of small intestine as shown in figure 66. Figure 72 show posteriorly the head lies on
the inferior vena cava, the right renal vessels, and bile duct.
Radiologist
reported there is no appearance of the mass start from figure 42. Meaning the mass end at the figure 41 where
the size of the mass is 4.5 x 5.4 cm located inferior to transverse colon at
the level of L2 L3. From the
radiologist, he noted that anteriorly this mass extends to the anterior
abdominal wall and posteriorly this mass extends to the para-aortic area
encasing the left renal artery and renal vein as shown in coronal section of CT
images figure 51 and figure 77.
Because
of the pancreatic mass, radiologist reported that the stomach is displaced
superomedially and compressed as show in coronal section image 57. The stomach shows in this CT images is filled
with oral contrast medium. Lumley et al.
(1987) described the normal anatomy of the stomach, it is usually J shape and
situated in the left hypochondrium and epigastrium, its lower part extending to
the level of the umbilicus. The stomach
is divided into fundus, a body and a pyloric portion (Lumley et al, 1987). The fundus is the part above the level of
esophageal opening; the body extends from the fundus to the angular notch and
the pyloric portion from the notch to the pyloric sphincter. The abnormal anatomy of this patient’s
stomach is compared with normal anatomy from other patient from axial section
of the CT images. Figure 17 shows body
of the stomach compressed by the mass and the diameter is only 1.6 cm compare
with figure 83 which shows normal shape of the stomach which is 5.9 cm in
diameter. Figure 13 shows fundus part of
the stomach is 4.6 cm in diameter while in normal images from other patient is
6.6 cm in diameter. This different in
diameter is due to compression of the mass to the stomach. Figure 32 shows pyloric part of the stomach
which is shifted, displaced and compressed, compared with figure 81 which shows normal position of pyloric part of the
stomach. Apart from this, radiologist
reported there is no clear plane of demarcation between this mass and the
greater curvature of the stomach.
Other
affected organ is liver. Radiologist
reported there are multiple liver lesions in both lobes of the liver in keeping
with liver metastasis. Liver metastasis
is a cancerous tumor that has spread to the liver. According to radiologist,
liver is divided into two lobes, right and left lobes, and there are eight
segments of the liver. Ryan and
McNicholas (1994) described, right lobe is divided into five segments which are
segment four (medial superior and medial inferor), segment five (anterior
inferior), segment six (posterior inferior), segment seven (posterior
superior), and segment eight (anterior superior) while left lobe is divided
into two segments which are segment two (lateral superior) and segment three
(lateral inferior). Segment one is
located at caudate lobe (Ryan & McNicholas, 1994).
In this
CT images, radiologist noted that there are tumor in segment four and segment
two of the liver. This can be seen in
figure 12. Radiologist reported the
largest tumor is in segment two measuring 8.6 x 5.3 cm. Tumor in segment two showed in figure 12
until figure 18 while tumor in segment four showed in figure 12 until figure
20. In figure 20, CT image shows only
small tumor measuring 1.4 x 1.4 cm.
Other than that, there are also tumors in segment five which can see
from figure 26 until figure 28. There are two tumors in segment five of the
liver show in figure 27. The anterior
tumor is 2.8 x 2.7 cm and posterior tumor is 2.2 x 2.6 cm. Other than tumor, there is also metastasis in
segment five of the liver which can be seen clearly in figure 32 to figure 37
measuring 5.9 x 4.2 cm. Radiologist also
stated that metastasis in segment six of the liver appear in figure 30
measuring 5.0 x 4.9 cm and can be seen until figure 44.
In
discussion with radiologist, noted that Hounsfield unit for normal liver area
for this patient is around 124 HU.
However, Leblanc (2012) stated that HU scale for normal liver is 40 to
60. This difference in HU is due to
contrast medium. Radiologist measure HU
of the liver with contrast enhanced while Leblanc (2012) measure HU of the
liver without contrast enhanced. Due to
contrast enhanced, HU for organ will increase.
Each tumor and metastasis in patient’s liver has difference HU
reading. For this patient, HU reading
for tumor in segment two is about 84 and tumor in segment 4 is about 47. Another two tumors in segment five are 41 HU
and 87 HU. Metastasis in segment five
shows HU reading about 55 and in segment six shows 64 HU. Radiologist noted that they usually compare
the HU reading with HU of water which is
zero. With reference to water, radiologist
can interpret whether the tumor or metastasis is either cystic or solid.
From secondary cancer in the lymph nodes (2011),
the author wrote that cancer cells can travel in the lymphatic system to nearby
lymph nodes to another part of the body.
When cancer grows inside lymph nodes, it usually affects the lymph nodes
near the tumor itself. These nodes are
the one that have been trying to filter out or kill the cancer cells (secondary cancer in the lymph nodes, 2011). According to radiologist, when there is
cancer, lymph nodes can get larger.
Radiologist noted that in normal patient, lymph nodes are usually tiny and
very hard to find in CT images. Like in
this patient, several lymph nodes become larger because of pancreatic
cancer. Meaning, cancer has spread to
the lymph nodes. Radiologist reported
that several lymph nodes that have been affected in this patient are
retrocrural lymph node, paraaortic lymph node, paracaval lymph node, celiac
lymph node, and portal lymph node.
Retrocrural lymph node showed in figure 23 until figure 28 measuring 1.1
x 2.7 cm. It is situated between the
spine and abdominal aorta in retrocrural space.
Another affected node is paraaortic lymph node. It is situated in front of the spine near the
aorta. This can be seen from figure 29
until figure 40. The large paraaortic
lymph nodes showed in figure 34 measuring 4.3 x 3.3 cm. Other than that, paracaval lymph nodes showed
in figure 35 measuring less than one centimeter which situated near the aorta
and inferior vena cava. Celiac lymph
nodes also measuring less than one centimeter showed in figure 27 near the
celiac axis. The last node noted is
portal lymph node situated anterior to portal vein measuring 4.5 x 3.1 cm. This can be
seen in figure 26 to figure 31.
Radiologist
reported that other organ like spleen is normal. The spleen is seen as homogenously enhancing
and there is no metastasis showed. Other
than that radiologist noted that the spleen size in this CT images look normal
which showed from figure 8 until figure 26 located in the left hypochondrium
posterior to pancreatic mass. According
to Ryan and McNicholas (1994), the spleen is enlarged if anterior to the aorta
or extending below the ribs. On CT,
normal size of the spleen is difficult to define because respiratory movement
between cuts, but it is assessed by the number of cuts on which the spleen is
visible (Ryan & McNicholas, 1994).
Gallbladder
is also normal as reported by radiologist.
Gallbladder images can be seen in figure 34 until figure 38. Lumley et al. (1987) noted that the
gallbladder is a pear-shaped sac lying in the right hypochondrium on the visceral
surface of the right lobe of the liver.
However in CT images of this patient, radiologist noted that gall
bladder looks a little bit compressed measuring 1.5 x 6.0 cm. This is obvious when compared to other images
from normal patient showed in figure 80 measuring
2.6 x 1.9 cm. Radiologist noted that
this maybe due to pancreatic mass which compressed the stomach and subsequently
the stomach compressed gallbladder.
Both
adrenals and right kidney appeared normal as reported by radiologist. However, radiologist reported that for the
left kidney there is fluid surrounding the left kidney as canbe seen in figure
29 and 30. The fluid could be blood,
urine or lymph. Based on the attenuation
value of the fluid which is 47, radiologist
suggests it is perinephric fluid.
According to Ryan and McNicholas (1994) for normal patient, on CT the
kidney is seen to be surrounded by perinephric fat and this is most abundant
medial to the lower pole of the kidney and this is a favoured site of
accumulation of blood, urine or pus in ruptured kidney. Apart from that, other structures of the
kidneys look normal. The size of this
patient’s kidneys showed in axial plane of CT images 6.0 x 5.3 cm. Ryan and
McNicholas (1994) suggested that in CT images for normal patient, at the hilum
the kidney measures 5.0 x 4.0 cm which when compared to this patient’s kidney
size is more or less the same and acceptable.
Other
abnormal thing that occurred and altered the normal anatomy of the area in
cancer patient is ascites. Radiologist
reported that there is minimal ascites present.
According to radiologist, ascites is an accumulation of fluid in the
peritoneal cavity, located in the space between tissue lining and abdominal
organ. This can be due to liver disease
and metastasis. Attenuation value for
ascites in the images is 28 HU which is according to radiologist, it is
exudative ascites because the HU is more than 15. From ascites
(2012), exudates ascites is defined as ascites with a protein content of
greater than 3g protein per 100ml of fluid and possible causes of exudates
ascites include malignant disease. Radiologist
also stated that there is ascites fluid around the liver as seen from figure 11
until figure 30. The thickest ascites is
showed in figure 16. Other than that
there is ascites fluid around the spleen also.
This can be seen in figure 11 until figure 27. There is also ascites present between the
abdominal lining and the stomach showed in figure 13 to figure 19. Other than ascites, radiologist also noted
that there is no pleural effusion present in early slice of the CT abdomen
which showed lung segment from figure 7 until figure 17. According to radiologist, if no pleural
effusion noted meaning there is no metastasis to the lung yet. From pleural
effusion (2012), pleural effusion is excess fluid that accumulates between
the two pleural layers, the fluid-filled space that surrounds the lungs. Common causes of pleural effusion are
pneumonia, cancer, viral infection, and pulmonary embolism (pleural effusion, 2012).
Arterial
and venous involvement also plays important roles. For this patient, there are some which are
abnormal because of pancreatic mass.
These are splenic artery and splenic vein. Radiologist noted that splenic vein is
thrombosed which showed in figure 18.
Splenic vein is the blood vessel that drains blood from the spleen. Radiologist mentioned, thrombosis of the
splenic vein means that there is a formation of a blood clot inside that blood
vessels, obstructing the flow of the blood.
Tan and Thomson (2005) stated that splenic vein thrombosis is usually
associated with acute pancreatitis, chronic pancreatitis and pancreatic
cancer. Other than that, radiologist
reported that splenic artery is encased with infiltration. This is due to pancreatic mass. The mass is completely encasing the splenic
artery showed from image 20 to image 26.
Splenic artery supplies oxygenated blood to the spleen. Other arteries and veins are considered
normal as suggested by radiologist.
Because
cancer already spread to the other organ, patient can only go for chemotherapy
as a treatment to pancreatic cancer.
Chemotherapy is a treatment that uses drugs to stop the growth of cancer
cells, either by killing or by stopping them from dividing (Nugent & Stuart,
2012). Talk about prognosis, for
metastatic disease, doctors estimated the survival rate is about ten percent and
within six month. However, without
active treatment, metastatic pancreatic cancer patient has a survival rate of
approximately three month only.
4. CONCLUSION
From
Tummala, Junaidi, and Agarwal (2011), the authors noted that pancreatic cancer
is the fourth leading cause of cancer-related death in the United States. Recent research shows the median size of
pancreatic carcinoma at the time of diagnosis is about 3.1 cm and has not
changed much in last three decades even though there is increasing major
advances in imaging technology that can help diagnose smaller tumors (Tummala
et al, 2011). This is because most of
pancreatic cancer patients are asymptomatic till late and have unclear
symptoms.
Takhar
(2004) noted that great improvements in non-invasive cross sectional
radiological imaging in the past decade have greatly enhanced the ability to
diagnose pancreatic cancer and help doctors to plan appropriate treatment for
patients. Other than that, accurate
radiological staging of the diseases also allows for appropriate clinical
decision making and ensures that surgery is limited to those patients who will
benefit.
Transabdominal
ultrasound is often the first imaging modality used. However, the current method of choice for
diagnosis and staging of pancreatic cancer is contrast enhanced computed
tomography where CT provides better tumor definition than does ultrasound
(Takhar, 2004).
CT scan
plays an important role for patients with suspected pancreatic carcinoma where
it can confirm the stage tumor and can determine if tumor is resectable or not
(Francis, 2004). Other than that, it also can detect the presence of distant
disease (metastases), local tumor extension, documented regional or distant
lymph node metastases, and arterial invasion or encasement of major arteries
(Francis, 2004). However, according to
Francis (2004), CT scan also have some limitations where its inability to detect
metastases to normal sized lymph nodes, small peritoneal metastases, less than
1cm hepatic metastases and subtle peripancreatic tumor extension.
Increased awareness of pancreatic cancer amongst the
clinicians and knowledge of the available imaging modalities and their optimal
use in evaluation of patients suspected to have pancreatic cancer can
potentially help in diagnosing more early stage tumors (Tummala, 2011).
5. REFERENCES
Lumley,
J.S.P., Craven, J.L., & Aitken, J.T. (1987). Essential anatomy (4th ed.). London: Churchill Livingstone.
Ryan,
S., & McNicholas, M. (1994). Anatomy
for diagnostic imaging (1st ed.). London: Saunders.
Francis, I.R. (2004).
Role of CT in detection and staging of pancreatic adenocarcinoma. Cancer
Imaging, 4(1), 10 – 14. doi: 10.1102/1470-7330.2003.0026
Molteni,
R. (2011). From CT Numbers To HU In Cone
Beam Volumetric Imaging. Retrieved December
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Takhar, A.S., Palaniappan, P., Dhingsa, R., & Lobo, D.N.
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Tummala, P., Junaidi, O.,
& Agarwal, B. (2011). Imaging of pancreatic cancer: An overview. J Gasrointest
Oncol, 2(3), 168 – 174. doi: 10.3978/j.issn.2078-6891.2011.036
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