Answer for BIR CoW 05 Sep 2021
Periampullary carcinoma arising from head of pancreas
Findings
Hypotonic duodenography reveals inverted figure 3 sign with mucosal irregularity of second part of duodenum • CECT reveals heterogeneously enhancing mass lesion arising from head of pancreas with areas of peripheral calcification • MRI reveals Peripherally enhancing T2 mixed intense lesion with solid and necrotic components with diffusion restriction noted arising from head of pancreas and located medially in the c loop of duodenum and extends into the superior recess of lesser sac,paraduodenal space displacing the right kidney posteriorly and duodenum laterally • The lesion displaces superior mesenteric artery medially towards left and superior mesenteric artery runs along the medial margin of the lesion • Mild prominent main pancreatic duct • No common bile duct dilatation
Discussion
Pancreatic adenocarcinoma occurs most commonly in the pancreatic head (65%) and usually presents on US as a hypoechoic solid mass with ill-defined margins . Masses in the head of the pancreas cause ductal obstruction with secondary dilatation of both the common bile duct and the pancreatic duct, and result in the so called double-duct sign. On Doppler studies, pancreatic ductal adenocarcinoma shows poor vascularity, as well as poor enhancement on all phases of contrast-enhanced US. This may be caused by marked desmoplasia, low mean vascular density, or the possible presence of necrosis and mucin. On CT, pancreatic adenocarcinomas most often appear as hypoattenuatingmasses . However, approximately 10% of pancreatic adenocarcinomas are isoattenuating relative to the background pancreatic parenchyma, especially in small tumors 2 cm or less, thus making diagnosis more difficult. In these situations, indirect (secondary) signs, such as upstream pancreatic duct dilation or the double-duct sign caused by pancreatic and common bile duct obstruction, are helpful for diagnosis. In addition, the pancreas distal to the tumor usually also appears atrophic. As the tumor grows, it typically infiltrates the peripancreatic structures and may result in encasement of adjacent vasculature and in some cases adjacent organs. Pancreatic cancers can occasionally appear to be cystic or necrotic, and in rare cases they can contain calcium. On MRI, pancreatic cancer typically appears hypointense on fat-suppressed, T1-weighted imaging and on pancreatic parenchymal phase, dynamically enhanced, fat-suppressed, T1-weighted sequences, whereas it has a variable appearance on T2-weighted images. Pancreatic cancer also has a variable appearance on diffusion-weighted images. HYPOTONIC DUODENOGRAPHY-reveals‘‘Inverted Figure 3’’ sign of periampullary carcinoma The ‘‘Inverted figure 3’’ sign was first described by Frostbergin 1938 as a mass effect on the medial duodenal wall with concomitant ampullary sparing due to tethering by the pancreatic and common bile ducts. This sign, which as appears as a ‘‘Classic’’ in barium form, is associated with pancreatic head enlargement and can be seen with ampullary carcinoma, carcinoma head of the pancreas, duodenal carcinoma, lymphoma, metastasis, or focal pancreatitis Characteristic bilobed impression is seen along the medial wall of the fluid-filled duodenum with the puckered/tethered appearance of the ampulla resulting in the ‘‘Inverted Figure 3’’ sign. When an ‘‘Inverted Figure 3’’ sign is observed, malignancy should be suspected and it is important to perform an abdominal MRI (T1, T2, and contrast-enhanced MR imaging) in addition to MRCP to image the ampullary and periampullary region
Findings
Hypotonic duodenography reveals inverted figure 3 sign with mucosal irregularity of second part of duodenum • CECT reveals heterogeneously enhancing mass lesion arising from head of pancreas with areas of peripheral calcification • MRI reveals Peripherally enhancing T2 mixed intense lesion with solid and necrotic components with diffusion restriction noted arising from head of pancreas and located medially in the c loop of duodenum and extends into the superior recess of lesser sac,paraduodenal space displacing the right kidney posteriorly and duodenum laterally • The lesion displaces superior mesenteric artery medially towards left and superior mesenteric artery runs along the medial margin of the lesion • Mild prominent main pancreatic duct • No common bile duct dilatation
Discussion
Pancreatic adenocarcinoma occurs most commonly in the pancreatic head (65%) and usually presents on US as a hypoechoic solid mass with ill-defined margins . Masses in the head of the pancreas cause ductal obstruction with secondary dilatation of both the common bile duct and the pancreatic duct, and result in the so called double-duct sign. On Doppler studies, pancreatic ductal adenocarcinoma shows poor vascularity, as well as poor enhancement on all phases of contrast-enhanced US. This may be caused by marked desmoplasia, low mean vascular density, or the possible presence of necrosis and mucin. On CT, pancreatic adenocarcinomas most often appear as hypoattenuatingmasses . However, approximately 10% of pancreatic adenocarcinomas are isoattenuating relative to the background pancreatic parenchyma, especially in small tumors 2 cm or less, thus making diagnosis more difficult. In these situations, indirect (secondary) signs, such as upstream pancreatic duct dilation or the double-duct sign caused by pancreatic and common bile duct obstruction, are helpful for diagnosis. In addition, the pancreas distal to the tumor usually also appears atrophic. As the tumor grows, it typically infiltrates the peripancreatic structures and may result in encasement of adjacent vasculature and in some cases adjacent organs. Pancreatic cancers can occasionally appear to be cystic or necrotic, and in rare cases they can contain calcium. On MRI, pancreatic cancer typically appears hypointense on fat-suppressed, T1-weighted imaging and on pancreatic parenchymal phase, dynamically enhanced, fat-suppressed, T1-weighted sequences, whereas it has a variable appearance on T2-weighted images. Pancreatic cancer also has a variable appearance on diffusion-weighted images. HYPOTONIC DUODENOGRAPHY-reveals‘‘Inverted Figure 3’’ sign of periampullary carcinoma The ‘‘Inverted figure 3’’ sign was first described by Frostbergin 1938 as a mass effect on the medial duodenal wall with concomitant ampullary sparing due to tethering by the pancreatic and common bile ducts. This sign, which as appears as a ‘‘Classic’’ in barium form, is associated with pancreatic head enlargement and can be seen with ampullary carcinoma, carcinoma head of the pancreas, duodenal carcinoma, lymphoma, metastasis, or focal pancreatitis Characteristic bilobed impression is seen along the medial wall of the fluid-filled duodenum with the puckered/tethered appearance of the ampulla resulting in the ‘‘Inverted Figure 3’’ sign. When an ‘‘Inverted Figure 3’’ sign is observed, malignancy should be suspected and it is important to perform an abdominal MRI (T1, T2, and contrast-enhanced MR imaging) in addition to MRCP to image the ampullary and periampullary region
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
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Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!