EUS diagnosis of pancreatic lipoma: a case report

EUS diagnosis of pancreatic lipoma: a case report Francesco Maria Di Matteo, MD, Lalit Shimpi, MD, DNB, Monica Pandolfi, MD, Carla Rabitti, MD, Carboni Fabio, MD, PhD, Armando Gabbrielli, MD, Guido Costamagna, MD, FACG Rome, Italy

Benign neoplasms of the pancreas that arise from mesenchymal elements are infrequent and represent only 1% to 2% of all pancreatic tumors.1 Although lipomas occur commonly at other sites, pancreatic lipomas are infrequent, and less than 25 cases have been reported.1-8 Most cases were diagnosed incidentally on imaging by transabdominal US, CT, or magnetic resonance imaging (MRI) for other indications, or on examination of surgical specimens. To our knowledge, there are no reports of pancreatic lipoma diagnosed by EUS and/or needle aspiration. We report a case of a 70-year-old woman in whom lipoma of the pancreas was diagnosed and confirmed by using EUS with FNA cytology.

the duct of Wirsung. The remainder of the pancreas appeared normal, with no associated lymphadenopathy. Transduodenal FNA was carried out under EUS guidance, with a 22-gauge needle (Echotip 1-22; Cook Endoscopy, Winston-Salem, NC), after confirming the absence of intervening vessels on color Doppler. Consistency of the lesion was noted to be soft while performing needle puncture. Four passages were carried out. There were no postprocedure complications. Aspirated tissue stained with Papanicolaou’s stain showed mature fat cells, without any atypia, along with monomorphic ductal epithelial cells (Fig. 3), thus confirming the diagnosis of an intrapancreatic lipoma. Follow-up EUS, 15 months later, showed no change in size or characteristics of the lesion.

CASE REPORT DISCUSSION

A 70-year-old woman was referred to our department with a provisional diagnosis of a mass in the uncinate process of the pancreas. The patient was asymptomatic. She had surgery for ductal carcinoma of the left breast (stage 1) 2 years earlier, with subsequent adjuvant chemoradiotherapy, and was recently noted to have mildly elevated tumor markers (carcinoembryonic antigen, 14 ng/mL [reference range: !4.6 ng/mL]; carbohydrate antigen 19-9, 63.9 U/mL [!37 U/mL]). Physical examination and other laboratory investigations were unremarkable. Barium enema and EGD were negative for malignancy. CT showed a nonhomogenous, hypodense (ÿ50 Hounsfield unit [HU]) lobulated nonenhancing lesion in the uncinate process, 30 mm in diameter, with an ill-defined plane of cleavage between the mass and the superior mesenteric vein. On MRI, the lesion had high-intensity signals on T1 and T2 sequences, with a loss of signal intensity on fat-suppressed T2-weighted images, features typical of adipose tissue (Fig. 1A and B). There was minimal compression of the terminal common bile duct (CBD) and the duct of Wirsung by the mass on MRCP. EUS was performed with an intention to clarify the etiology of the mass. Examination was carried out by using an EG-3830-UT linear-array echoendoscope (Pentax Europe GmbH, Hamburg, Germany) and an EUB525 US processor (Hitachi Medical Corp, Tokyo, Japan) by using 5, 7.5, and 10 MHz frequencies. EUS showed a mixed-echogenic lobulated lesion in the uncinate process that measured 34  30 mm (Fig. 2). It appeared heterogenous, with hyperechoic strands within, and an irregular hyperechoic rim that suggested the presence of a fibrous capsule. It was surrounded by pancreatic parenchyma on all sides and appeared to mildly compress the CBD and

An intrapancreatic lipoma is a rare entity, and its true incidence is unknown.9,10 Most patients are asymptomatic, and the tumor is incidentally detected when imaging is done for other reasons.11,12 It may be easily confused with focal fatty infiltration of the pancreas, a diagnosis that depends on demonstration of contact with peripancreatic fat on imaging and the presence of acinar tissue within the lesion on microscopy.1,10 A pancreatic lipoma, on the other hand, is composed of lobules of mature adipose cells, delineated from surrounding pancreatic tissue by a thin fibrous capsule.1 Based on imaging alone, it may be difficult to differentiate these 2 lipomas.13,14 However, it is easy to conclude, on CT or MRI, that the lesion is predominantly composed of adipose tissue. In fact, few investigators believe that pathologic examination is necessary to confirm the diagnosis of pancreatic lipoma, because radiologic features are almost diagnostic.6,9 However, a well-differentiated lipogenic liposarcoma may mimic a benign lesion because of sharply defined margins and homogeneity of fat-tissue density.6,15 Only 4 cases of pancreatic liposarcoma have been reported, with little radiologic data.1,9 Our patient presented with elevated levels of tumor markers and a history of a malignancy known to metastasize to pancreas.16,17 These issues prompted us to use EUS to resolve the issue. To our knowledge, this is the first report of the utility of EUS for the diagnosis of an intrapancreatic lipoma. EUS allows detailed morphologic examination of such lesions and, more importantly, provides an additional tool of FNA capability. Transabdominal puncture for cytology may give inaccurate results, especially in small

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Brief Reports

Figure 2. EUS image showing a lobulated, capsulated mixed-echogenic mass in head of pancreas.

Figure 3. Microscopic image of aspirate from the mass, showing mature adipocytes (arrow) with interspersed ductal epithelial cells (arrowhead) (Papanicolaou’s stain, orig. mag. 200).

invasive diagnostic modality in experienced hands with which to confirm the etiology of such pancreatic masses.19,20 Figure 1. A, T1-weighted MRI image of intrapancreatic fatty tumor. B, T1-weighted MRI image after fat suppression, showing significant loss of signal intensity.

DISCLOSURE None of the authors have any disclosures to make.

retroperitoneal or pancreatic tumors and may lead to incorrect therapeutic decisions.2 Furthermore, it carries the risk of complications, such as tumor seeding and pancreatic fistula.7 EUS-guided FNA has largely supplanted percutaneous FNA for sampling lesions in the pancreas, especially those close to the duodenal wall.18 Because the overall risk of complications is very low, it is a safe and accurate minimally www.giejournal.org

REFERENCES 1. Raut CP, Fernandez-del Castillo C. Giant lipoma of the pancreas: case report and review of lipomatous lesions of the pancreas. Pancreas 2003;26:97-9. 2. Bigard MA, Boissel P, Regent D, et al. Intrapancreatic lipoma. First case in the literature. Gastroenterol Clin Biol 1989;13:505-7. 3. Erdem LO, Erdem CZ, Comert M. Intrapancreatic lipoma and Morgagni hernia: a previously unrecognised association. Dig Dis Sci 2004;49:1962-5.

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Brief Reports 4. Magenta Biasina A, Curti A, Bonifacio C, et al. CT diagnosis of pancreatic lipoma: a case report and literature review. Radiol Med (Torino) 2002;104:367-9. 5. Mazet N, Garcier JM, Mofid R, et al. Intrapancreatic lipoma: a rare, easily diagnosed tumor [in French]. Presse Med 2002;23:317. 6. Di Maggio EM, Solcia M, Dore R, et al. Intrapancreatic lipoma: first case diagnosed with CT. AJR Am J Roentgenol 1996;167:56-7. 7. Merli M, Fossati GS, Alessiani M, et al. A rare case of pancreatic lipoma. Hepatogastroenterology 1996;43:734-6. 8. Boglino C, Inserra A, Silvano A, et al. Intrapancreatic lipoma: a case report [in Italian]. Pediatr Med Chir 1993;15:397-9. 9. Ozlem B, Mutlu C, Tulin Y, et al. Fat containing unusual tumor of the pancreas. Eur Radiol 2002;12:770-3. 10. Ryan MF, Hamilton PA, Smith AJ, et al. Radiologic features of pancreatic lipoma. Can Assoc Radiol J 2003;54:41-4. 11. Itai Y, Saida Y, Kurosaki Y, et al. Focal fatty masses of the pancreas. Acta Radiol 1995;36:178-81. 12. Katz DS, Nardi PM, Hines J, et al. Lipomas of the pancreas. AJR Am J Roentgenol 1998;170:1485-7. 13. Itai Y. Fatty mass of the pancreas is not equal to lipoma of the pancreas. Am J Roentgenol 1999;172:551-2. 14. Secil M, Igci E, Goktay AY, et al. Lipoma of the pancreas: MRI findings. Comput Med Imaging Graph 2001;25:507-9. 15. Waligore MP, Stephens DH, Soule EH, et al. Lipomatous tumors of the abdominal cavity: CT appearance and pathologic correlation. AJR Am J Roentgenol 1981;137:539-45.

16. Volmar KE, Jones CK, Xie HB. Metastases in the pancreas from nonhematologic neoplasms: report of 20 cases evaluated by fine-needle aspiration. Diagn Cytopathol 2004;31:216-20. 17. Moussa A, Mitry E, Hammel P, et al. Pancreatic metastases: a multicentric study of 22 patients. Gastroenterol Clin Biol 2004;28:872-6. 18. DeWitt J, Jowell P, LeBlanc J, et al. EUS-guided FNA of pancreatic metastases: a multicenter experience. Gastrointest Endosc 2005;61: 689-96. 19. O’Toole D, Palazzo L, Arotcarena R, et al. Assessment of complications of EUS-guided fine-needle aspiration. Gastrointest Endosc 2001;53: 470-4. 20. Eloubeidi MA, Gress FG, Savides TJ, et al. Acute pancreatitis after EUS-guided FNA of solid pancreatic masses: a pooled analysis from EUS centers in the United States. Gastrointest Endosc 2004; 60:385-9.

Digestive Diseases Unit, Universita` Campus Bio Medico, Rome, Italy. Reprint requests: Francesco Maria Di Matteo, MD, Digestive Diseases Unit, Universita` Campus Bio Medico, Via Emilio Longoni, 89, Rome 00155 Italy. Copyright ª 2006 by the American Society for Gastrointestinal Endoscopy 0016-5107/$32.00 doi:10.1016/j.gie.2006.02.015

Successful endoscopic resection of ampullary adenoma with intraductal extension and invasive carcinoma (with video) Aaron J. Small, MSIII, Todd H. Baron, MD, FASGP Rochester, Minnesota, USA

Although endoscopic resection of ampullary adenomas is becoming more accepted, intraductal extension is considered by some investigators to be a contraindication to endoscopic therapy. We describe a patient with intraductal extension of an adenoma that contained invasive carcinoma; it was completely resected endoscopically, as confirmed at subsequent pancreaticoduodenectomy. This case attests to the feasibility of complete endoscopic resection of ampullary adenomas with intraductal extension. If radical surgery had not been performed, then longterm follow-up to monitor recurrence would have been necessary to further validate our success of carcinoma resection.

A 61-year-old woman was discovered to have an ampullary adenoma after she presented with painless jaundice. Biopsy specimens from biopsies performed at an outside facility revealed tubular adenoma, with high-grade intraepithelial neoplasia. An abdominal CT showed a 2  3  3-cm

ampullary mass, with high-grade obstruction of the common bile duct. ERCP was performed with a therapeutic duodenoscope (TJF-130; Olympus Corp, Melville, NY). A large, ampullary, polypoid lesion (measuring 2.5  1.5 cm) at the level of the major papilla was seen (Fig. 1). Cholangiography revealed filling defects in the distal common bile duct consistent with ampullary tissue into the distal bile duct (Fig. 2). All of the external portion of the lesion was resected with a polypectomy snare in piecemeal fashion by using an ERBE generator (ERBE generator ICC200EA, USA Incorporated Surgical Systems, Marietta, Ga), with settings of Autocut 200 W and coagulation of 20 W, with the Endocut feature on (Video 1, available online at www.giejournal.org). A wide biliary sphincterotomy was then performed and exposed the intraductal adenomatous tissue, which was then snare resected by using the same electrocautery settings. The biliary sphincterotomy was wide enough to allow direct endoscopic visualization into the distal bile duct, where the small amount of residual tissue was snare resected and treated with the ERBE APC 300 with a straight fire probe at 10 L flow and 45 W. A pancreatogram after ampullectomy was

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CASE REPORT