Journal of the Louisiana State Medical Society
over, ERCP could show distortion of pancreatic or biliary ducts by MCNs, which is in favor of ma- lignant nature of MCNs. ERCP could also relieve the biliary obstruction in patients with jaundice. However, ERCP is not necessary for diagnosis and is not used in most patients with MCNs. Like ERCP, MRCP could also be helpful in differentia- tion of pseudocysts or branch duct IPMNs from MCNs. 1 By providing a clear imaging of the tail of pancreas and its ductal system, EUS could also be helpful in differentiating MCNs from other cystic lesions. 1 Moreover, EUS could be used for FNA. FNA could also be achieved percutaneously under CT-guidance. FNA analysis of MCNs shows hon- eycomb sheets and clusters of mucin-producing columnar cells. Abundant mucin in the background of the MCNs could be helpful in differentiation of these lesions from serous cystic neoplasms or pseudocysts. 11 The degree of cellular atypia in FNA could also be predictive of malignancy. 12 Because of the possibility of malignant trans- formation of MCNs, they should be resected ir- respective of their size or location. 1,5 MCNs are usually located in the body and tail of the pancreas; 5 open, laparoscopic, or robotic distal pancreatectomy with or with- out splenectomy is the operation of choice for these lesions. 1 MCNs could also rarely happen in the head of the pancreas; formal pancreatoduodenectomy is the operation of choice for these lesions. 1 Extra caution should be implemented during the surgery not to rupture the cyst, as it could lead to intra-abdominal seeding of tumor cells. 1 Moreover, in order to provide an optimal sample for pathologist, the cyst should be removed intact and not marsupialized. 1 Complete resection of MCNs with benign nature is considered a complete cure. 1,10 These lesions do not recur; therefore, no follow-up imaging is needed. 1,13 However, patients with malignant lesions have poor prognosis; their five-year survival is 15%-35%. 13 The most important predic- tor of prognosis in malignant MCNs is the extent of tumor invasion. 14 After resection, patients with malignant MCNs are recommended to have follow-up imaging with CT or MRI for evaluation of possible recurrences or metastases. 1 In summary, we present a case MCN of pancreas with characteristic pathological finding of ovarian-type stroma in a man. Our study shows that MCN could occur in men and should be considered in the differential diagnosis of pancreatic lesions in men, as well as women. REFERENCES 1. Sakorafas GH, Smyrniotis V, Reid-Lombardo KM, et al. Primary pancreatic cystic neoplasms revisited: part II. Mucinous cystic neoplasms. Surg Oncol . 2011;20:e93-101. 2. Yamao K, Yanagisawa A, Takahashi K, et al. Clinicopathological features and prognosis of mucinous cystic neoplasmwith ovarian- type stroma: a multi-institutional study of the Japan pancreas society. Pancreas . 2011;40:67-71.
ovarian-type stroma is essential for pathological diagnosis of MCNs. 1,3 MCNs typically occur in premenopausal women. 1,2 To our knowledge, only 10 cases of MCN in men diagnosed based on WHO criteria have been previously reported in the literature. 2-8 Our case is the 11th case of MCN reported in a man. Because MCNs rarely happen in men, to rule out any chromosomal abnormality in our patient, we performed karyotyping, which showed normal male XY karyotype. This shows that MCNs can happen in men without any chromosomal abnormality. As in our patient, MCNs are usually asymptomatic and are incidentally found during abdominal imaging for evaluation of another often unrelated clinical indication. 1 However, MCNs can occasionally present with abdominal pain and fullness, nausea, vomiting, recurrent pancreatitis, or gastric outlet obstruction. 1,5,9 Presence of symptoms such as weight loss or jaundice should raise the suspicion of the malignant nature of the MCNs. 1,9 In cross-sectional imaging by ultrasonography, CT, or MRI, MCNs are usually found as spherical macrocystic masses. 1 MCNs usually do not communicate with pancreatic ducts but could result in the dilatation of the pancreatic ducts through pressure effect and obstruction. 1,10 The following findings in the imaging of MCNs are in favor of malignant nature of these lesions: large size (>5cm), the presence of calcification, multiple papillary invaginations, a mural node or asymmetrically thickened wall, an eccentrically located mass within a cystic area, local vascular invasion, pericystic reaction, extrahepatic biliary obstruction, splenic vein obstruction or ascites. 1,5 ERCP could be very helpful in differentiation of MCNs which usually do not communicate with pancreatic ducts versus psuedocysts or branch duct IPMNs which communicate with pancreatic ducts. 1 More- Figure 1: Abdominal CT scan showing a cystic mass in the tail of the pancreas (arrow).
68 J La State Med Soc VOL 166 March/April 2014
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