A spongy mass with central sunburst calcify-cation in CT abdomen is seen in: (AIIMS Nov 2012)
|C||Adenocarcinoma of pancreas|
a. Serous cystadenomas (microcystic adenomas) are the second most common cystic tumors of the pancreas. The clinical presentation of serous cystadenomas is similar to that of mucinous cystic pancreatic tumors.
b. An association with VHL disease has been described.
c. Most patients present with nonspecific symptoms of vague abdominal pain or discomfort, but many have a palpable mass.
d. These tumors can be large, with a size of 1-25 cm. Because of increasing use of cross-sectional imaging, many of these tumors are detected as an incidental, asymptomatic finding.
e. On CT scans, sunburst central calcification in a spongy mass is pathognomonic of this tumor, but this finding occurs only in 10% of patients.
f. Endoscopic Ultrasonography (EUS) allows better resolution of the eycomb structure than CT. At times, the cysts may be large, a feature that makes it difficult to differentiate these cysts from MCNs.
g. Hypervascularity may be demonstrated on angiograms, and some tumors occur with intra abdominal hemorrhage.
h. Analysis of the cyst fluid characteristically reveals low viscosity and low levels of CEA, with negative cytologic results for malignant cells, as the vast majority of serous cystadenomas are benign.
i. Surgical resection is the treatment of choice for symptomatic tumors and tumors that show continuous growth.
j. Many of these tumors may require a Whipple procedure or distal pancreatectomy, depending on the anatomic location. Distal pancreatectomy may be performed and the spleen can be preserved, given the absence of malignant potential.
Mucinous cystic neoplasms
a. Nonenhanced CT scans show a well-defined, unilocular or multilocular, externally smooth, round-to-ovoid mass with fluid attenuation.
b. The attenuation values of the multilocular cysts vary according to the degree of hemorrhage or protein in the mucoid
c. Visualization of nodular or papillary excrescences with irregular borders of the septae is possible. If present, calcification is curvilinear or punctate and confined to the cyst wall or septa. Contrast enhanced
d. CT scans show enhancement of the cyst wall, internal septations, mural nodules, and other intracavitary projections. CT more clearly demonstrates enhancement of cystic walls and septa than do other studies.
e. Compared with serous cystic tumors, the cysts in MCNs are larger (>20 mm in diameter) and less numerous (usually <6).
f. CT guided aspiration of the cyst can provide further diagnostic clues and enable their differentiation from other pancreatic cystic masses (eg, pseudocyst, serous cystadenoma, and solid and pseudopapillary neoplasm).
g. MCN cyst fluid typically has a high viscosity, low amylase levels, and high CEA and carbohydrate antigen (CA) 72-4 levels, and they may show malignant cytology in patients with mucinous cystadenocarcinomas.
h. Periodic acid Schiff (PAS) and May Grunwald/Giemsa (MGG) stains are usually positive for extracellular as well as intracellular mucin.
i. Treatment is same as that of serous cystadenoma.