Indian Journal of Radiology and Imaging Indian Journal of Radiology and Imaging

ABDOMINAL IMAGING
Year
: 2003  |  Volume : 13  |  Issue : 4  |  Page : 395--397

Imaging of mucinous cystadenoma of pancreas


SB Patel, SR Shah, V Goswami, HC Soni, R Vyas, YM Gohil 
 Department of Radio-diagnosis, Gujarat Cancer & Research Institute, Asarwa, Ahmedabad - 380016, India

Correspondence Address:
H C Soni
Department of Radio-diagnosis, Gujarat Cancer & Research Institute, Asarwa, Ahmedabad - 380016
India




How to cite this article:
Patel S B, Shah S R, Goswami V, Soni H C, Vyas R, Gohil Y M. Imaging of mucinous cystadenoma of pancreas.Indian J Radiol Imaging 2003;13:395-397


How to cite this URL:
Patel S B, Shah S R, Goswami V, Soni H C, Vyas R, Gohil Y M. Imaging of mucinous cystadenoma of pancreas. Indian J Radiol Imaging [serial online] 2003 [cited 2019 Aug 24 ];13:395-397
Available from: http://www.ijri.org/text.asp?2003/13/4/395/28716


Full Text

 Introduction



Cystic tumors of the pancreas are relatively uncommon, accounting for 10% of cystic lesions of the pancreas, and 1 % of pancreatic neoplasms [1]. Mucinous cystic neoplasms (MCN), serous cystadenomas, and intraductal papillary mucinous tumors (IPMT) comprise more than 90% of the primary cystic neoplasms of the pancreas, but other pathologic entities with cystic appearance are also known like Cystic Islet Cell Tumor and Papillary Cystic Tumor. Tumors with malignant potential include MCN, IPMT, papillary cystic neoplasms, and cystic islet cell tumors. Serous cystadenomas, in contrast, are almost universally benign. Accurate recognition of these lesions is important because of their ability to masquerade as pancreatic pseudo-cysts and their high cure rate following surgical treatment.

Case History

Thirty-year-old female patient presented with complaints of mild pain in epi-gastric region for the last eight months. No history or a hematemesis or vomiting. On examination, a mass noted in the right hypochondrial region. No evidence of tenderness or icterus noted. USG of abdomen was performed with 7.5 MHz linear array transducer and 3.5 MHz sector scanner. On USG & cystic lesion with internal septae and calcification was noted in the region of head and uncinate process of pancreas medial to second part of duodenum. No evidence of dilatation of pancreatic duct noted. Body, tail of pancreas appeared normal. No other abnormality was found on USG. Contrast Enhanced CT scan was performed which showed the same findings as seen on USG. Enhancement of septae noted with calcification.

We put the diagnosis of Mucinous Cystic Neoplasm of pancreas. Patient was operated. The histopathological examination confirmed the diagnosis of mucinous cystic adenoma.

 Discussion



Mucinous Cystic Neoplasm (also called macrocystic adenoma and Mucinous adenocarcinoma) are the most frequently encountered cystic tumors of the pancreas. They occur mainly in women in the fifth and sixth decade of life.[2]

Grossly, MCN is mucin producing unilocular or multilocular neoplasms of the pancreas arising in the peripheral ductal system. This neoplasm produces large volume of mucin that results in cystic appearance on imaging studies.[3],[4] Cysts range in size from 2 to 26 cm in maximum diameter. They are located mainly in the body and tail and less commonly in the head of the pancreas. The cyst wall is thick (0.1-0.2 cm in diameter) and has mural papillary projections within the cavities or contains intramural firm nodules. A dense fibrous capsule surrounds the neoplasm. Calcification may be present both in the capsule as well as in the internal septa dividing the tumour into separate cystic spaces containing mucin, haemorrhagic fluid and/or debris. Some neoplasms consist of one large cyst and several smaller daughter cysts. The neoplasrt may contain one or more solid components. Current pathologic classification distinguishes between benign, borderline or malignant (cystadenocarcinomas) tumors based on their maximal degree of dysplasia. This classification scheme correlates to patient prognosis, and suggests that these tumors should be treated as premalignant lesions with eventual evolution to aggressive behavior if left untreated.

Patients usually complain primarily of abdominal pain or palpable mass. Symptoms such as weight loss and jaundice are more common with malignant tumors. Today, with the more liberal application of CT scanning in medical evaluations, an increasing percentage of tumors are being diagnosed while asymptomatic.

Ultrasound typically shows a multilocular fluid containing mass with good transmission and strong acoustic enhancement.[2],[5] Ultrasound is particularly advantageous to show the internal septations, mural nodules and solid excrescencies of the cyst wall. CT may also allow identification of solid components associated to cystic elements, features of borderline or malignant tumors.

The internal architecture of mucinous cystadenoma and cystadenocarcinoma is displayed by MRI equally well or better than by CT, except for its limited ability to reveal calcification within the lesion. Pancreatography rarely demonstrates cyst communication with pancreatic ducts, but frequently shows duct displacement by mass effect or ductal obstruction in 25% of malignant MCN.

Although no finding is an absolute indicator of benign and malignant disease, obstruction of pancreatic duct occurs in 60% of malignant lesions and in 2.5% of benign disease. Arteriography reveals hypervascularity of the wall, of the septations and of the mural nodules in case of malignant lesion. Obstruction of the splenic artery and vein due to direct tumour encasement or invasion are readily displayed on CT. ERCP and arteriography can be used to differentiate mucinous cystadenoma from cystadenocarcinoma.

Differential diagnosis

Patient evaluation after discovery of a cystic lesion of the pancreas should initially be directed towards exclusion t k.a pancreatic pseudocyst [6]. As opposed to cystic 2o-plasms, pseudocysts lack an epithelial lining, and represent collections of pancreatic secretions, which have extravasated from a duct disrupted by inflammation or obstruction. Patients with pseudocysts often have a history of acute or chronic pancreatitis, while most of those with cystic tumors lack such antecedent factors. Radiographic characteristics which favor a diagnosis of pseudocyst over cystic neoplasms include: lack of septae, loculations, solid components, or cyst wall calcifications on CT; hypovascularity on angiography; and communication between the cyst and the pancreatic ductal system on ERCP. Aspiration of pseudocyst contents reveals high levels of amylase in practically all cases.

The clinical presentation of serous cystadenomas is similar to that of MCN, occurring mostly in females (80%) with a mean age of 63 years. Serous cystadenomas consist of well-circumscribed pancreatic neoplasms, which on cross-section show numerous tiny cysts separated by delicate fibrous septae giving them a honeycomb appearance. The cysts are filled with clear watery fluid, and are often arranged around a central stellate scar which may be calcified. The pathognomonic Image by CT scan is that of a spongy mass with a central sunburst calcification, but occurs in a minority of patients. Hypervascularity may be demonstrated by angiography. An Intraductal papillary mucinous tumour (IPMT) represent papillary neoplasms within the main pancreatic duct which show mucin hypersecretion that often leads to duct dilatation and/or chronic obstructive pancreatitis. IPMT are considered premalignant pancreatic lesions, and histologically may demonstrate areas ranging from hyperplasia to carcinoma within a single tumor. Most reported case series demonstrate that IPMT occur primarily in males with a mean age of 65 years, in contrast to the female predominance in MCN. Patients frequently present with abdominal pain or pancreatitis, and may be found to have a past history of recurrent pancreatitis. The disease is most commonly localized to the head of the pancreas, but may occur at any site along the pancreatic ductal system. Duct dilatation is often impressive and may mimic MCN on CT scan imaging. Evaluation by ERCP typically shows a patulous ampulla of Vater with extruding mucus, which is often diagnostic for I PMT. Other findings during pancreatography include: main duct dilation, filling defects (viscid mucus), and communication between cystic areas and the main pancreatic duct.

If accurate diagnosis is not possible despite all efforts, resection rather than observation is preferred[7],[8]

References

1Fernandez-del Castillo C, Warshaw AL (1995) Cystic tumors of the pancreas. Surg Clin North Am 75: 1001-1016
2Buetow PC, Rao P, Thompson LD, Mucinous cystic neoplasm of the pancreas; radiologic-pathologic correlation, RadioGraphics 1998;19:807-811
3Adsay NV, Pierson C, Sarkar F et al. Colloid (mucinous non-cystic) carcinoma of pancreas, Am J Surg Pathol 2001;25: 26-42
4Whang ee, Danial T, Dunn JC, et al. The spectrum of mucin-producing adenocarcinoma of pancreas, Pancreas 2000:21:147-151
5Scott J, Martin I, Redhead D, Hammond P, Garden OJ, Mucinous cystic neoplasm of the pancreas: Imaging features and diagnostic difficulties. Clin Radiol 2000;55:187-192
6Martin I, Hammond P, Scott J, Redhead D, Carter DC, Garden OJ (1998) Cystic tumors of the pancreas. Br J Surg 85: 1484-1486
7Alles AJ, Warshaw AL, Southern JF, Compton CC, Lewandrowski KB (1994) Expression of CA 72-4 (TAG72) in the fluid content of pancreatic cysts. Ann Surg 219: 131-134
8Hammel P, Levy P, Voitot H, Levy M et al(1995) Preoperative cyst fluid analysis is useful for the differential diagnosis of cystic lesion of pancreas. Gastroenterology 108: 1230-1235