Incidentally detected small pancreatic cyst is a therapeutic challenge. As these lesions include a spectrum of pathologies ranging from benignlesions to malignant mucinous tumors, it is important to differentiate potential malignant mucinous cystic neoplasms (MCN) from others.However, a definitive diagnosis might be difficult, since computed tomography (CT) and magnetic resonance imaging (MRI) cannot depict themorphologic features characteristic of small MCN.This report presents a case of a small pancreatic cyst incidentally detected during medical check-up for inguinal hernia. Although the preoperativediagnosis was uncertain with CT and MRI, the diagnosis of MCN was strongly suspected because the majority of MCN tend to oftenoccur in elderly women and the most common locations are in the pancreatic tail. Laparoscopic ultrasonography (LUS) was employed to obtaina correct diagnosis, and it showed a 16 mm cyst with characteristic features indicating a diagnosis of MCN. The patient underwent alaparoscopic distal pancreatectomy and the diagnosis of MCN was confirmed histopathologically. In conclusion, LUS allowed a timely curativeresection of a small MCN in this case

Iwata Toru

Kanematsu Takashi

Kanetaka Kengo

Kawashita Yujo

Ono Shinichiro

Nagasaki University's Academic Output SITE: NAOSITE

IntroductionThe widespread use of cross-sectional imaging modalities formultiple indications has allowed for the discovery of cystic lesionsin the pancreas. In fact, up to 75% of these cystic lesions are inci-dentally found by such modalities in asymptomatic patients.1The question to resolve is how to manage these lesions: surgicalresection or observation, since they can be divided into two groups,i.e., inflammatory processes such as pseudocysts after pancreatitis,and cystic neoplasms such as serous cystadenoma and mucinouscystic neoplasm (MCN). Especially MCN encompass a broadspectrum of pathologies ranging from benign, borderline, to malig-nant.2 Any tumor within this group has the potential to transforminto an invasive carcinoma, thus it is important to identify themucinous neoplasms from nonmucinous counterparts. However,these incidentally detected lesions are generally too small to showthe characteristic morphologic features on computed tomography(CT) and magnetic resonance imaging (MRI), making a definitivediagnosis difficult.This report presents a case with a small pancreatic cyst incidentallydetected during a medical check-up for an inguinal hernia operation.The diagnosis was uncertain, till the laparoscopic ultrasonography(LUS) was performed to suggest a diagnosis of MCN. A distalpancreatectomy was subsequently performed in order to preservethe spleen in laparoscopic manner.Case ReportA 66-year-old female was admitted with a tentative diagnosis ofa pancreatic cyst which was incidentally detected in a preoperativeworkup at another hospital with a diagnosis of a right inguinal her-nia. She had no symptoms, no past history of pancreatitis and noremarkable physical signs other than a right groin lump. Her labo-ratory findings showed a slight elevation of transaminase, but amy-lase and other pancreatic enzymes were within normal range. TheActa Med. Nagasaki 54: 73－76Address correspondence: Kengo Kanetaka, M.D., Ph.D., Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1Sakamoto, Nagasaki 852-8501 JAPANTEL: +81-(0)95-819-7316, FAX: +81-(0)95-819-7319, E-mail: kkanetaka@kce.biglobe.ne.jpReceived September 18, 2009; Accepted December 21, 2009MS#AMN 07056Case ReportSmall Mucinous Cystic Neoplasm of the Pancreas Successfully Detectedand Resected by a Laparoscopic Approach: Report of a CaseKengo KANETAKA,1,2 Yujo KAWASHITA,1 Shinichiro ONO,1 Toru IWATA,1 Takashi KANEMATSU21 Department of Surgery, Nagasaki Rousai Hospital, Sasebo, Japan2 Department of Surgery, Nagasaki University, Graduate School of Biomedical Sciences, Nagasaki, JapanIncidentally detected small pancreatic cyst is a therapeutic challenge. As these lesions include a spectrum of pathologies ranging from benignlesions to malignant mucinous tumors, it is important to differentiate potential malignant mucinous cystic neoplasms (MCN) from others.However, a definitive diagnosis might be difficult, since computed tomography (CT) and magnetic resonance imaging (MRI) cannot depict themorphologic features characteristic of small MCN.This report presents a case of a small pancreatic cyst incidentally detected during medical check-up for inguinal hernia. Although the preop-erative diagnosis was uncertain with CT and MRI, the diagnosis of MCN was strongly suspected because the majority of MCN tend to oftenoccur in elderly women and the most common locations are in the pancreatic tail. Laparoscopic ultrasonography (LUS) was employed to obtaina correct diagnosis, and it showed a 16 mm cyst with characteristic features indicating a diagnosis of MCN. The patient underwent alaparoscopic distal pancreatectomy and the diagnosis of MCN was confirmed histopathologically. In conclusion, LUS allowed a timely curativeresection of a small MCN in this case.ACTA MEDICA NAGASAKIENSIA 54: 73－76, 2009Keywords: Ileum; Laparoscopic surgery; Mucinous cystic neoplasm; PancreasKengo Kanetaka et al.: Laparoscopic Management of Small Pancreatic Cystlevel of the tumor markers, carcinoembryonic antigen and carbo-hydrate antigen 19-9 were 1.82 ng/ml (<5 ng/ml) and 17.61 U/ml(<35 U/ml), respectively. Abdominal CT revealed a 16-mmunilocular simple cyst in the pancreatic tail (Figure 1). No dilata-tion of the main pancreatic duct or calcification of parenchyma wasdetected. Abdominal MRI was employed, without any additionaldiagnostic information.The nature of the pancreatic cyst was uncertain on these modali-ties; however, we suspected a diagnosis of a neoplastic cyst, ratherthan a pseudocyst because of the absence of parenchymal calcifica-tions, ductal dilatation of the pancreas, and no history of pancreatitis.The most suspected diagnosis was MCN because the majority ofMCN tends to often occur in elderly women and the most commonlocations are in the pancreatic tail. This has a malignant potentialregardless of its size, therefore, the differentiation between pseudocystand MCN was needed for appropriate treatment. However, endoscopicultrasonography (EUS) was not indicated because of the potentialrisks of this method. As a result, we planned to perform herniorrhaphyin a laparoscopic manner in order to conduct simultaneous LUS.The patient was fully informed about this disease, and she pre-ferred to undergo a subsequent distal pancreatectomy rather thanhave a long-term intensive follow-up if the cyst would be identi-fied to be a mucinous neoplastic growth.Under general anesthesia, the patient was placed in the righthemilateral position. After the insertion of 4 ports for herniaorrhaphy,the gastrocolic ligament was divided; therein the anterior surfaceof the pancreas was exposed. No pancreatic cyst was evident onlaparoscopic inspection. LUS showed a well-circumscribed cystmeasuring 16 mm in diameter, with septal formation, and a finespeckled internal echo in the tip of the pancreatic tail, however, nomalignant specific features such as wall thickness, calcification, orsolid components were seen (Figure 2). These findings wereconsistent with a diagnosis of MCN, so as a total biopsy, a distalpancreatectomy with preservation of the spleen was carried outlaparoscopically.After the insertion of 2 additional ports, the opening of gastrocolicligament was enlarged to expose the entire pancreas. The short gastricvessels were carefully spared to maintain the splenic blood supply.The inferior border of the pancreas was dissected, and the bodyand tail were separated from the retroperitoneum. The splenic arteryand vein were carefully dissected and preserved. Finally, the pan-creas was transected 1 cm proximal to the tumor with the endoscopicstapling device. The resected specimen was wrapped in a plasticbag and removed through the infraumblical port (Figure 3). The74Figure 1. CT shows a thin-wall cystic lesion measuring less than 2 cm.Internal septation or nodularity in the cyst was not detected.Figure 2. LUS findings of a cystic lesion in the tail of pancreas. LUSclearly shows a cyst of 16 mm in diameter with septal formation and finespeckled internal echo.Figure 3. Gross pathology of resected specimen showed thin septationssurrounding mucin-filled cystic cavities.Kengo Kanetaka et al.: Laparoscopic Management of Small Pancreatic Cystcolor and viability of the spleen was confirmed. Subsequently,laparoscopic herniorrhaphy was performed with a transabdominalprocedure. The duration of the operation was 350 minutes. Theintraoperative blood loss was under 250 g. The histological exami-nation revealed mucinous cystic adenoma and no atypia was found.Ovarian type stroma was also noted in the interstitium (Figure 4).The post operative course was uneventful. Oral intake began on2nd day and the patient was discharged from the hospital on 14thpostoperative day.DiscussionSmall pancreatic cysts incidentally detected on CT often forcesurgeons to determine the optimal management, resection or obser-vation. Spinelli et al. reported that pancreatic cysts are seen in1.2% of 24,000 patient CT scans.3 On the other hand, Kimura et al.found pancreatic cysts which measured at least 0.4 cm in size in 73of 300 autopsy series.4 Although this high incidence comes fromthe inclusion of very small cysts discovered only in autopsy stud-ies, this discrepancy might imply that as the resolution of cross-sectional imaging modalities such as CT and MRI are improved,the frequency of the detection of incidental small cystic lesions inthe pancreas will increase. In fact, in a recent review of MRI ex-aminations, pancreatic cysts, 82% of which were smaller than 1cmin diameter, were detected in 20% of patients.5Since these cystic lesions comprise a variety of pathologies in-cluding pseudocysts after pancreatitis, benign tumors like serouscystadenoma, and borderline or malignant tumors like MCN,2 it isimportant to obtain the clues to differentiate neoplastic from non-neoplastic lesions, especially potential malignant MCN. Recent ad-vances in cross-sectional diagnostic modalities have now made itpossible to depict the characteristic appearance of pancreatic cysts.These features includes lobular shaped masses with calcificationgenerally arranged in a central stellate pattern in serous cystadenoma,and a well-circumscribed round cyst containing with thick septationsand rim calcifications in MCN.6 However, small lesions tend tolimit radiographic characterization for the differential diagnosis.The natural history of small asymptomatic pancreatic cysts isunknown, but many studies have indicated nonsurgical manage-ment for selected patients with these lesions. Most previous studieshave focused on the potentially malignant nature of mucinousneoplasms. Fernandez-del Castillo et al. reported on 212 patientswith pancreatic cystic lesions measuring 2 cm or smaller. Most oftheir patients underwent surgery, thus resulting in a histopathologicaldiagnosis. Although the incidence of malignancy was low (1 of 28,3 %), a mucinous lesion was discovered in over half of theirresected patients. Because of the malignant potential of these tu-mors, they recommended intensive imaging follow-up in patientswith small mucinous cysts.1 A prospective study of 221 patients byWalsh et al., reported the successful differentiation of mucinouscysts from nonmucinous counterparts using radiography and EUS-guided aspiration.7 In their study, a surgical resection was advisedif medically fit patients had symptoms or cysts that were suspectedto have a mucinous nature. With this approach, patients with inci-dental asymptomatic cysts could thus be followed without a de-layed resection for any missed mucinous neoplasms at a meanfollow-up period of 24 months.7EUS is a diagnostic tool for cystic lesions in the pancreas. Koitoet al. reported that even in tumors measuring less than 2 cm, theEUS accuracy ranges between 82% and 91%.8 On the other hand,despite high resolution images of EUS, Walsh et al. reported thatin their series of 87 patients with suspected pancreatic cysts, EUSimaging did not yield any additional diagnostic information thanthat obtained by noninvasive modalities such as CT and MRI.9 Thesame difficulty has also been demonstrated in several studies in-cluding one by Brugge et al., who investigated the differentiation ofmucinous from nonmucinous cystic neoplasms using EUS either aloneor in combination with fine needle aspiration in 112 histologicallyconfirmed patients. They concluded that EUS imaging alone eventhrough the use of strict morphologic criteria was insensitive andnonspecific (the sensitivity and specificity were 56% and 45%, re-spectively).10LUS has been adopted as a complimentary technique to laparoscopyfor pancreatic malignancies, in which LUS is used to detect vascu-lar invasion as well as liver metastasis and nodal metastasis.11-13 Inaddition, high resonance of direct contact LUS allows the discrimi-nation of the internal architecture of a cystic lesion more clearlythan CT and MRI. Schachter et al. introduced LUS for surgical de-cision making in patients with pancreatic cysts. They were able todetect novel, additional features such as solid components or addi-tional small cysts in 8 of 15 examined patients, which could not bedetected through conventional cross-imaging modalities.14In our patient, LUS depicted a small well-circumscribed cystwith internal architecture such as septal formation, and a finespeckled internal echo. These findings highly suggested a diagno-sis of a MCN,14 which has the potential to transform into an75Figure 4. Histological features of the wall of the resected MCN. Ovarian-type stroma composed of spindle cell bundles located immediately beneaththe neoplastic columnar epithelium.Kengo Kanetaka et al.: Laparoscopic Management of Small Pancreatic Cystinvasive carcinoma regardless of its size, though other malignant-specific characteristics, such as a solid component and irregularthickened wall15 could not be detected. Because of the difficulty ofdistinguishing mucinous cystic carcinoma from its benign counter-part and the predicted long life expectancy of the patient, a distalpancreatectomy with conservation of the spleen was performed.We selected neither a cytology nor cyst fluid analysis followingfine needle aspiration, which has the potential to spill tumor cellsinto the abdominal cavity.Various approaches have been developed for spleen preservationduring a distal pancreatectomy. Kimura et al. performed a distalpancreatectomy with the spleen conservation after careful removaland preservation of the splenic vessels from the pancreas.16Although their procedure is somewhat tedious and time-consuming, it ensures the blood supply to the spleen, and reducesthe risk of splenic necrosis and abscess formation. Fernande-Cruzet al. introduced this procedure into the laparoscopic field. Theyaccentuated the advantage of a magnified laparoscopic view whichfacilitates the separation of the splenic vessels from the pancreasand identification of the small branches. Advanced laparoscopicinstruments could thus make it easy and safe to manage these ves-sels.17The need to conduct an LUS examination of all pancreatic cyststhat remain undetermined based on a multidisciplinary diagnosticapproach, including EUS, remains controversial. While the pri-mary resection of small pancreatic cysts has been advocated,18,19this aggressive approach may be unacceptable because the majorityof these lesions are asymptomatic, and there are also risks associ-ated with the possibility of exposing patients with benign lesionsto surgical morbidity and mortality. Schachter et al. advocated thatLUS under general anesthesia should be used for differential diag-nosis of pancreatic cysts,20 however, their method is still invasiveand prohibitively expensive. Therefore, LUS should be performedin medically fit patients who are highly suspected to have malig-nant cystic lesions on CT and MRI examinations.In our case, CT and MRI did not show any characteristic fea-tures, however we strongly suspected a diagnosis of MCN becausethe majority of MCN tend to occur often in elderly women and themost common locations are in the pancreatic tail. Our patient wastherefore scheduled to undergo hernioraphy under general anesthe-sia, and therefore we could perform LUS simultaneously. This en-abled us to perform a timely curative resection for a small MCN inthis case.References1. Fernandez-del Castillo C, Targarona J, Thayer SP, Rattner DW, Brugge WR,Warshaw AL. Incidental pancreatic cysts: Clinicopathologic characteristics andcomparison with symptomatic patients. Arch Surg 138: 427-34, 20032. Brugge WR, Lauwers GY, Sahani D, Fernandez-del Castillo C, Warshaw AL.Cystic neoplasms of the pancreas. N Engl J Med 351: 1218-26, 20043. Spinelli KS, Fromwiller TE, Daniel RA, Kiely JM, Nakeeb A, Komorowski RA,et al. Cystic pancreatic neoplasms: Observe or operate. Ann Surg 239: 651-9, 20044. Kimura W, Nagai H, Kuroda A, Muto T, Esaki Y. Analysis of small cystic lesionsof the pancreas. Int J Pancreatol 18: 197-206, 19955. Zhang XM, Mitchell DG, Dohke M, Holland GA, Parker L: Pancreatic cysts:Depiction on single-shot fast spin-echo mr images. Radiology 223: 547-53, 20026. Procacci C, Carbognin G, Accordini S, Biasiutti C, Guarise A, Lombardo F, et al.CT features of malignant mucinous cystic tumors of the pancreas. Eur Radiol 11:1626-30, 20017. Walsh RM, Vogt DP, Henderson JM, Zuccaro G, Vargo J, Dumot J, et al. Naturalhistory of indeterminate pancreatic cysts. Surgery 138: 665-71, 20058. Koito K, Namieno T, Nagakawa T, Shyonai T, Hirokawa N, Morita K: Solitarycystic tumor of the pancreas. EUS-pathologic correlation. Gastrointest Endosc 45:268-76, 19979. Walsh RM, Henderson JM, Vogt DP, Baker ME, O'Malley CM, Jr., Herts B, et al.Prospective preoperative determination of mucinous pancreatic cystic neoplasms.Surgery 132: 628-34, 200210. Brugge WR, Lewandrowski K, Lee-Lewandrowski E, Centeno BA, Szydlo T,Regan S, et al. Diagnosis of pancreatic cystic neoplasms: A report of the coopera-tive pancreatic cyst study. Gastroenterology 126: 1330-6, 200411. Callery MP, Strasberg SM, Doherty GM, Soper NJ, Norton JA. Staginglaparoscopy with laparoscopic ultrasonography: Optimizing resectability inhepatobiliary and pancreatic malignancy. J Am Coll Surg 185: 33-9, 199712. John TG, Greig JD, Carter DC, Garden OJ. Carcinoma of the pancreatic head andperiampullary region. Tumor staging with laparoscopy and laparoscopicultrasonography. Ann Surg 221: 156-64, 199513. Minnard EA, Conlon KC, Hoos A, Dougherty EC, Hann LE, Brennan MF.Laparoscopic ultrasound enhances standard laparoscopy in the staging of pancre-atic cancer. Ann Surg 228: 182-7, 199814. Sidden CR, Mortele KJ. Cystic tumors of the pancreas: ultrasound, computedtomography, and magnetic resonance imaging features. Semin Ultrasound CT MR28: 339-56, 200715. Schachter PP, Avni Y, Gvirz G, Rosen A, Czerniak A. The impact of laparoscopyand laparoscopic ultrasound on the management of pancreatic cystic lesions. ArchSurg 135: 260-4, 200016. Kimura W, Inoue T, Futakawa N, Shinkai H, Han I, Muto T. Spleen-preservingdistal pancreatectomy with conservation of the splenic artery and vein. Surgery120: 885-90, 199617. Fernandez-Cruz L, Saenz A, Astudillo E, Pantoja JP, Uzcategui E, Navarro S.Laparoscopic pancreatic surgery in patients with chronic pancreatitis. Surg Endosc16: 996-1003, 200218. Goh BK, Tan YM, Chung YF, Chow PK, Ong HS, Lim DT, et al. Non-neoplasticcystic and cystic-like lesions of the pancreas: May mimic pancreatic cysticneoplasms. ANZ J Surg 76: 325-31, 200619. Siech M, Tripp K, Schmidt-Rohlfing B, Mattfeldt T, Widmaier U, Gansauge F, etal. Cystic tumours of the pancreas: Diagnostic accuracy, pathologic observationsand surgical consequences. Langenbecks Arch Surg 383: 56-61, 199820. Schachter PP, Shimonov M, Czerniak A. The role of laparoscopy and laparoscopicultrasound in the diagnosis of cystic lesions of the pancreas. Gastrointest EndoscClin N Am 12: 759-67, 200276

Small Mucinous Cystic Neoplasm of the Pancreas Successfully Detected and Resected by a Laparoscopic Approach: Report of a Case

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Small Mucinous Cystic Neoplasm of the Pancreas Successfully Detected and Resected by a Laparoscopic Approach: Report of a Case

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