Solitary true cyst of the pancreas in two adults: analysis of cyst fluid and review of the literature

Simple mucinous cyst: another potential cancer precursor in the pancreas? Case report with molecular characterization and systematic review of the literature

Cystic lesions of the pancreas may range from benign to precursors of pancreatic cancer. Simple mucinous cyst (SMC) is larger than 1 cm, has a gastric-type flat mucinous lining, and minimal atypia without ovarian-type stroma. We report a new case of pancreatic SMC, coupling a systematic review of the English literature mainly focused on their clinic-pathological features. We reviewed 103 cases of SMC in adults (73 women), averaging 57 (range, 26–70) years. The SMCs were located in the body-tail region of the pancreas in 60 (58%) cases, presenting as single cystic lesions in 94% of cases; 43% of patients were asymptomatic. A preoperative fine-needle aspiration of the cyst fluid detected amylase and carcinoembryonic antigen positivity in 71% and 76% of cases, respectively. Patients underwent surgery mostly for suspected malignancy; in 83% of cases, a standard pancreatic resection was performed. Mean SMC size was 4.9 (range, 1.5–12.0) cm. Mucins MUC5AC and MUC6 resulted positive in 77% and 81% of cases performed, respectively, whereas MUC2 was negative in all but one patient. The SMC from our institution was characterized by a KRAS somatic mutation. The diagnosis of SMC should be considered when a solitary pancreatic cyst larger than 1 cm is detected in asymptomatic patients. To establish a correct diagnosis, an extensive histologic/immunohistochemical analysis is essential. The presence of a KRAS mutation highlights that SMC may represent another potential pancreatic cancer precursor.

Laparoscopic spleen-preserving distal pancreatectomy in a solitary true pancreatic cyst

BACKGROUND

Solitary true pancreatic cysts (STPCs), or epithelial cysts, are benign lesions that are extremely rare in adult patients. Advances in radiographic techniques have improved the ability to identify pancreatic cystic lesions. We report a case of a large and symptomatic STPC in a 47-year-old female patient who was treated successfully with spleen-preserving laparoscopic distal pancreatectomy. We also review the clinical and pathologic features of all reported STPCs within the past 25 years.

DATABASE

To compose the review, we did a search of the international literature for STPCs that had occurred in adults. Fourteen related articles were found describing cases of STPCs. Clinical and pathologic information was collected for all of the reported pancreatic cysts, and a database was formed. STPCs are detected more frequently in women than in men. The mean age of occurrence is 43.2 years, and the mean cyst size is 5.6 cm. Fifty percent of true cysts are located in the head of the pancreas. Size and site are responsible for the symptoms caused, although 22.8% were asymptomatic. Diagnosis was made postoperatively in all cases by histopathologic studies. No case of malignancy was reported in any STPC.

CONCLUSIONS

STPCs are rare and benign lesions commonly discovered incidentally during abdominal imaging. Surgical treatment is considered the appropriate therapy for large and symptomatic STPCs. The definitive diagnosis is established by histopathologic and immunohistochemical studies.

Incidental pancreatic cystic lesions: is there a relationship with the development of pancreatic adenocarcinoma and all-cause mortality?

PURPOSE

To establish the effect of incidental pancreatic cysts found by using computed tomographic (CT) and magnetic resonance (MR) imaging on the incidence of pancreatic ductal adenocarcinoma and overall mortality in patients from an inner-city urban U.S. tertiary care medical center.

MATERIALS AND METHODS

Institutional review board granted approval for the study and waived the informed consent requirement. The study population comprised cyst and no-cyst cohorts drawn from all adults who underwent abdominal CT and/or MR November 1, 2001, to November 1, 2011. Cyst cohort included patients whose CT or MR imaging showed incidental pancreatic cysts; no-cyst cohort was three-to-one frequency matched by age decade, imaging modality, and year of initial study from the pool without reported incidental pancreatic cysts. Patients with pancreatic cancer diagnosed within 5 years before initial CT or MR were excluded. Demographics, study location (outpatient, inpatient, or emergency department), dates of pancreatic adenocarcinoma and death, and modified Charlson scores within 3 months before initial CT or MR examination were extracted from the hospital database. Cox hazard models were constructed; incident pancreatic adenocarcinoma and mortality were outcome events. Adenocarcinomas diagnosed 6 months or longer after initial CT or MR examination were considered incident.

RESULTS

There were 2034 patients in cyst cohort (1326 women [65.2%]) and 6018 in no-cyst cohort (3,563 [59.2%] women); respective mean ages were 69.9 years ± 15.1(standard deviation) and 69.3 years ± 15.2, respectively (P = .129). The relationship between mortality and incidental pancreatic cysts varied by age: hazard ratios were 1.40 (95% confidence interval [ CI confidence interval ]: 1.13, 1.73) for patients younger than 65 years and 0.97 (95% CI confidence interval : 0.88, 1.07), adjusted for sex, race, imaging modality, study location, and modified Charlson scores. Incidental pancreatic cysts had a hazard ratio of 3.0 (95% CI confidence interval : 1.32, 6.89) for adenocarcinoma, adjusted for age, sex, and race.

CONCLUSION

Incidental pancreatic cysts found by using CT or MR imaging are associated with increased mortality for patients younger than 65 years and an overall increased risk of pancreatic adenocarcinoma.

Malignant potential in incidental pancreatic cysts

Although pancreatic cysts are being diagnosed with greater frequency, a uniform agreement on management is still lacking. This is mainly because accurate and reliable preoperative determination of the exact pathology of a pancreatic cyst remains elusive. Although ultrasound-guided fine needle aspiration represents a significant advancement in our ability to characterize pancreatic cysts preoperatively, significant limitations persist. In this article, we review the roles of clinical characteristics, imaging features and biochemical markers in the correct classification of incidental pancreatic cysts. The correct diagnosis and management of these cysts still hinges, to a large extent, on clinical experience and multidisciplinary cooperation.

A new case of solitary true pancreatic cyst

A true cyst of the pancreas is extremely rare, and few cases have been reported in adult patients. The authors report a new case of this rare pathological entity. A 35-year-old male patient was admitted to our unit with a cystic mass, about 6cm in diameter, located in the pancreatic head, in proximity to the duodenum, vena cava, biliary tree and right kidney. Clinical features and imagery were suggestive for a benign neoplasm, as did surgical findings. Cystoduodenostomy was done. Histological finding revealed a cyst lined by cuboidal epithelium without morphologic alterations. Analysis of the cyst fluid showed a high level of CA 19-9 (10,000Uml(-1)). After 1-year follow-up, the patient was found to be doing well without any abdominal symptoms. Ultrasound images revealed no cyst recurrence.

Solitary true cyst of pancreas: report of a case and review of literature

CONTEXT

Solitary true cysts of the pancreas in adults are extremely rare, and only few cases have been reported in the literature. The etiology and natural history of these lesions remain unknown, and treatment is not standardized. We describe an additional resected case.

CASE REPORTS

A 55-year-old female who presented to us with a history of heaviness and pain in right upper abdomen for 1 year. CT scan of abdomen showed a large unilocular cyst in the region of the head of the pancreas. The patient underwent pancreatico-duodenectomy with binding pancreaticojejunostomy. The histology of cyst revealed true unilocular pancreatic cyst lined by cuboidal epithelium. She is well after 3 years of follow-up.

CONCLUSIONS

A preoperative work-up alone does not always allow an accurate diagnosis, but it is useful in determining lesion characteristics and guiding therapeutic decision-making. When surgery is indicated, a limited resection is warranted in most cases.

Current management of cystic neoplasms of the pancreas

Over the last decade there has been a dramatic increase in the number of patients identified with pancreatic cysts. This increase has been largely attributed to advances in imaging. The majority of these cysts represent benign neoplasms; however, a significant fraction of these are pre-malignant or malignant. Because the majority of these neoplasms are benign, many reports have advocated a selective approach to surgical resection. Here we review the literature that has contributed to the development of our approach to the management of these cystic neoplasms. We provide an overview of the key features in diagnosis and in predicting malignancy. Particular attention is given to the natural history and management of intraductal papillary mucinous neoplasms (IPMN).

Imaging Spectrum of Cystic Pancreatic Lesions: Learn from Atypical Cases

The classic radiologic findings of cystic pancreatic masses have been well recognized; however, diagnosing those lesions is still challenging since many cases show unusual radiologic findings. We reviewed the computed tomography, magnetic resonance, and endoscopic retrograde cholangiopancreatography findings of many pathologically proven cystic pancreatic masses and selected various atypical but instructive cases as well as rare pathologic cases from the past 10 years in our institution. This article presents atypical as well as rare pathologic cases of cystic pancreatic masses and correlates them with pathologic findings to obtain diagnostic clues to perform a correct diagnosis.

Pancreatic cysts: a proposed management algorithm based on current evidence

BACKGROUND

Currently, the management strategy of pancreatic cyst (PC) remains controversial because of the inability to diagnose this type of cyst accurately and the limited knowledge of its natural history. Previously, many clinicians have advocated an aggressive resectional policy. This approach is no longer appropriate, and the number of PCs detected incidentally has increased. This study reviews the present literature and attempts to provide a management algorithm of pancreatic cysts based on currently available evidence.

METHODS

A Medline search was conducted to identify studies investigating PC, with particular emphasis placed on studies addressing its diagnosis and management. Additional articles were obtained from the reference lists of key articles and recent reviews.

COMMENTS

Based on current evidence, the optimal management of PC remains an art and should be individualized based on the risk-benefit ratio of surgery, which is influenced by multiple factors, such as the patient's potential life expectancy, surgical risk; and malignant potential of the cyst. Our proposed management algorithm is based on an individual's predicted risk-benefit ratio of surgery. Prospective evaluation of the algorithm is needed to determine its integrity.

Cystic neoplasms of the pancreas

This article presents the approach to the most commonly encountered pancreatic cystic masses that the authors employ at the University of Pittsburgh Medical Center. Variations on this approach are to be expected, based on several factors, including the availability of sophisticated imaging equipment and personnel.

Cystic lesions of the pancreas: an appraisal of an aggressive resectional policy adopted at a single institution during 15 years

BACKGROUND

Although an aggressive resectional approach toward pancreatic cysts has been advocated in the past, many clinicians now deem this therapeutic strategy impractical given the rapidly increasing incidence of incidentally detected pancreatic cystic lesions. The aim of this study was to review the aggressive resectional policy toward pancreatic cysts adopted at our institution during the past 15 years.

METHODS

One hundred nine consecutive patients who underwent surgical resection of a cystic lesion of the pancreas during a 15-year period were retrospectively reviewed. To determine subsets of patients at lower risk of having a malignant cyst, the clinicopathologic features (in particular, the malignant potential) of these patients were compared as a function of 3 variables, ie, presence of symptoms, patient age, and cyst size, using univariate analyses. Results were expressed as median and range and P < .05 was considered statistically significant.

RESULTS

Forty-three (39%) of 109 patients were asymptomatic. Incidental cysts were smaller (28 [10 to 240] vs 59 [10 to 200] mm, P < .001) and were found in older patients (55.0 [18 to 77] vs 45.5 [14 to 82] years, P = .003). Overall, 14% of asymptomatic cysts, versus 35% of symptomatic cysts, were malignant (P = .016). Incidental cysts were also less likely to be premalignant or malignant compared with symptomatic cysts (47% vs 70%, P = .015). Twenty (18%) patients were elderly (73.0 [70 to 82] years old). Elderly patients had a more equal sex distribution (45% vs 76% female, P = .005) and had smaller cysts (26 [10 to 200] vs 55 [10 to 240] mm, P = .003) that involved the head of the pancreas more frequently (8 [40%] vs 17 [19%], P = .045) compared with their younger counterparts. The cohort of elderly patients also had a higher median American Society of Anesthesiologists score (2 [1 to 3] vs 1 [1 to 3], P < .001), and a higher proportion had undergone a "more" major procedure (Whipple's or total pancreatectomy) (55% vs 18%, P < .001). Not unexpectedly, surgical morbidity in the elderly was significantly higher (10 [50%] vs 24 [27%], P = .045). The operative mortality in both groups was not significantly different (1 [5%] vs 1 [1%], P = .324). The proportion of premalignant or malignant lesions in elderly patients was also similar to that in younger patients (11 [55%] vs 55 [62%], P = .574). The size of a cyst in asymptomatic patients had no correlation with its potential for malignancy.

CONCLUSIONS

Reliance on preoperative characteristics alone such as the presence of symptoms, cyst size, and patient age are not sufficiently reliable in determining the malignant potential and thus management approach toward pancreatic cysts.

NON-NEOPLASTIC CYSTIC AND CYSTIC-LIKE LESIONS OF THE PANCREAS: MAY MIMIC PANCREATIC CYSTIC NEOPLASMS

BACKGROUND

Cystic lesions of the pancreas consist of a broad range of pathological entities. With the exception of the pancreatic pseudocyst, these are usually caused by pancreatic cystic neoplasms. Non-neoplastic pancreatic cystic and cystic-like lesions are extremely rare. In the present article, the surgical experience with these unusual entities over a 14-year period is reported.

METHODS

Between 1991 and 2004, all patients who underwent surgical exploration for a cystic lesion of the pancreas were retrospectively reviewed. Patients with a pancreatic pseudocyst were excluded. There were 106 patients of whom 8 (7.5%) had a final pathological diagnosis consistent with a non-neoplastic pancreatic cystic or cystic-like lesion, including 3 patients with a benign epithelial cyst, 2 with a pancreatic abscess (one tuberculous and one foreign body), 2 with mucous retention cysts and 1 with a mucinous non-neoplastic cyst. These eight patients are the focus of this study.

RESULTS

There were six female and two male patients with a median age of 61.5 years (range, 41-71 years). All the patients were of Asian origin including seven Chinese and one Indian. Four of the patients were asymptomatic and their pancreatic cysts were discovered incidentally on radiological imaging for other indications. All the patients underwent preoperative radiological investigations, including ultrasonography, computed tomography or magnetic resonance imaging, which showed a cystic lesion of the pancreas. Three patients, all of whom were symptomatic, were diagnosed preoperatively with a malignant cystic neoplasm on the basis of radiological imaging. Two patients were eventually found to have a pancreatic abscess, one tuberculous and the other, secondary to foreign body perforation. The third patient was found on final histology to have chronic pancreatitis with retention cysts. The remaining five patients had a preoperative diagnosis of an indeterminate cyst; on pathological examination, they were found to have a benign epithelial (congenital) cyst (n = 3), retention cyst (n = 1) and mucinous non-neoplastic cyst (n = 1). At a median follow up of 20 months (range, 3-34 months), none of the patients had any evidence of recurrent disease.

CONCLUSION

Non-neoplastic cystic and cystic-like lesions of the pancreas are rare causes of pancreatic cystic lesions that are generally benign and do not require surgery when asymptomatic. However, despite advances in diagnostic investigations such as endoscopic ultrasound with fluid aspirate and magnetic resonance imaging, the preoperative diagnosis remains unreliable. Hence, the challenge for all clinicians is to recognize these lesions preoperatively and to avoid 'unnecessary' surgery.

True Solitary Pancreatic Cyst in an Adult: Report of a Case

The differential diagnosis of cystic neoformations in the pancreas is challenging. We report a case of a true solitary cyst of the pancreas in a 26-year old woman. Abdominal magnetic resonance imaging and computed tomography showed a unilocular neoformation in the head of the pancreas, without obstruction of Wirsung's duct. We excised the cyst and performed Roux-en-Y loop pancreaticojejunostomy, but the patient suffered recurrent acute pancreatitis from Wirsung's duct stenosis. Thus, a new Roux-en-Y loop pancreaticojejunostomy was successfully done 6 months later. Histologically, the cyst was lined by cuboidal epithelium, immunohistochemically positive to anti-carbohydrate antigen 19-9 antibodies. To our knowledge, only 11 cases of solitary true cyst of the pancreas in adults have been reported, so the characteristics of this unusual entity are not well known. We propose a scheme for the differential diagnosis of cystic neoformations of the pancreas, starting from the histopathological definition of a true solitary cyst.

The natural history of the incidentally discovered small simple pancreatic cyst: long-term follow-up and clinical implications

OBJECTIVE

The purpose of our study was to determine the natural history of small (</= 2 cm) simple pancreatic cystic lesions.

MATERIALS AND METHODS

A retrospective review was performed of patients with long-term follow-up who were diagnosed with small (</= 2 cm) simple pancreatic cysts on sonography or CT from 1985 to 1996. Long-term surveillance included radiographic surveillance of 5 years or longer, clinical follow-up of 8 years or longer, or response to questionnaire or telephone inquiry 8 year or longer after the original diagnosis. Cause of death was recorded for patients who died within 5-8 years of diagnosis. Patients were excluded if a history of pancreatitis or systemic cystic disease existed.

RESULTS

Seventy-nine patients had small simple pancreatic cysts. Forty-nine (62%) had adequate radiologic, clinical, or questionnaire follow-up. Of the 22 patients with radiologic follow-up, 13 (59%) had cysts that remained unchanged or became smaller (mean size, 8 mm; mean follow-up, 9 years), and nine (41%) had cysts that enlarged, from a mean of 14 mm to a mean of 26 mm (mean follow-up, 8 years). Of the 27 patients with clinical or questionnaire follow-up (mean follow-up, 10 years), none developed symptomatic pancreatic disease. Eighteen patients (23%) died within 8 years without adequate radiologic follow-up, none of pancreas-related causes. Twelve patients (15%) were lost to follow-up.

CONCLUSION

Although small, incidental, simple pancreatic cysts of 2 cm or smaller may enlarge over a prolonged time, morbidity or mortality due to these small simple cysts is extremely unlikely, and observation appears to be a safe management option.

Diagnostic imaging of cystic pancreatic neoplasms

Cystic pancreatic neoplasms are being diagnosed with growing frequency due to improving imaging technologies and increasing clinician awareness. Distinguishing cystic neoplasms from pseudocysts and discriminating among the various cystic neoplasms is essential to appropriate management. The backbone of diagnosis of these tumors continues to be cross-sectional imaging by CT and MRI. Despite refinements in technology and significant progress in characterizing these lesions, the overall accuracy of CT and MR is limited. EUS, especially as means of FNA, will have an increasing role in the evaluation of selected cases as experience grows. No radiologic investigation can reliably distinguish cystic neoplasms from pseudocysts nor differentiate among cystic neoplasms in all cases. For uncertain lesions, surgeons should favor either careful observation with serial imaging or surgical resection.

Mucin Secreting Cystic Lesions of the Pancreas: Treatment by Enucleation

Ninety per cent of pancreatic cysts are inflammatory pseudocysts. The other 10 per cent are congenital or neoplastic and include congenital true cysts, retention cysts, lymphoepithelial cysts, the mucinous cystadenoma, mucinous cystadenocarcinoma, and serous microcystic cystadenomas and the more recently described intraductal papillary mucin-secreting neoplasms. The advent of computerized tomographic scanning, endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasonography (EUS) has brought many of these lesions to light when they are minimally symptomatic or are incidentally found while investigating unrelated problems. If there is any suspicion of actual or potentially malignant disease, then total excision of the lesion with part of or the entire pancreas is indicated to achieve a likely cure, as survival is better than for the more common ductal adenocarcinomas. There are few reliable preoperative studies to distinguish accurately the etiology and prognosis of this spectrum of cystic lesions, and usually the actual diagnosis is made only at the time of operation or histopathologic examination after the cystic lesion has been biopsied or excised. If a cyst is confirmed to be totally benign, as in the congenital true cyst, lymphoepithelial cyst, or a benign mucinous cyst, they may lend themselves to nonoperative observation or excision without sacrifice of pancreatic parenchyma. However, many mucin-producing cystic lesions may evolve into a dysplastic or invasive malignant lesion requiring more aggressive resective treatment, and it is important not to miss that diagnosis early when cure is still possible. This report presents four benign mucin-secreting cysts treated by local excision. All four were in the head of the pancreas and communicated with the main pancreatic duct and lacked ovarian-type stroma, thus categorizing them as side-branch intraductal papillary mucinous neoplasms. These lesions were able to be easily dissected out of the pancreas with only one patient developing a transient pancreatic fistula. Intraoperative and final histopathology confirmed the benign status, and these patients have remained disease free 3 to 5 years postoperatively. A review of benign tumors reported to have been treated by cyst enucleation in the literature confirms the rationale of this approach in highly selected lesions.

Laparoscopic enucleation of solitary true pancreatic cyst in an adult

Solitary or true pancreatic cyst is a very rare pathologic condition; only a few cases are reported in literature. We report a case of a 22-year-old woman with a symptomatic true pancreatic cyst located in proximity to the pancreatic head, duodenum, vena cava, biliary tree, and right kidney, which was enucleated through a laparoscopic approach. Laparoscopic ultrasound imaging allowed the surgeon to better identify the morphology of the cyst and its relationship with the adjacent structures. The treatment is briefly reviewed and discussed.

Solitary true cyst of the pancreas in an adult: report of a case

BACKGROUND

Solitary true cyst of the pancreas is rare in adults, and the differential diagnosis of cystic lesions of the pancreas is challenging.

AIM OF THE STUDY

To describe a solitary true cyst of the pancreas in an adult and discuss the differential diagnosis.

METHODS

A 50 yr old woman presented with a mass lesion in the right upper quadrant of the abdomen. Abdominal computed tomography showed a cystic lesion, with a maximum diameter of 12 cm, between the inferior surface of the liver and the ascending colon. The cyst was homogenous and had smooth edges. On magnetic resonance imaging, a unilocular cyst was seen that was low intensity on T1-weighted images and very high intensity on T2-weighted images. No connection between the cyst and the pancreatic ductal system was demonstrated on endoscopic retrograde cholangiopancreatography. Laparotomy was performed with a presumptive diagnosis of cystic tumor of the pancreas.

RESULTS

On pathologic examination, the cyst was serous and was lined with a single layer of normal cuboidal epithelium that was periodic acid Schiff stain negative. Meticulous examination failed to identify honeycomb-like microcysts characteristic of serous cystadenoma. The final diagnosis was a solitary true cyst of the pancreas.

CONCLUSION

The differential diagnosis of solitary true cyst from other cystic lesion of the pancreas usually is based on histology. Particular care must be taken to distinguish this lesion from macrocystic serous cystadenoma.

Pancreatic cysts: depiction on single-shot fast spin-echo MR images

PURPOSE

To evaluate single-shot fast spin-echo (SE) magnetic resonance (MR) imaging for depiction of pancreatic cysts in a large number of patients and to analyze cyst prevalence with respect to patient age and sex and other clinical information.

MATERIALS AND METHODS

Single-shot fast SE images of the pancreas were obtained in 1,444 patients. The images were reviewed for presence of pancreatic cysts, which were classified as simple and nonsimple types, and cyst diameters were measured. kappa statistic, Fisher exact, McNemar Q, and Pearson product moment correlation tests were performed.

RESULTS

Two hundred eighty-three (19.6%) patients had at least one pancreatic cyst. The prevalence of pancreatic cysts increased with age (r = 0.96). The percentages of male and female patients with pancreatic cysts (20.4% vs 18.8%) were not significantly different. Two hundred seventy-one (18.8%) patients had simple cysts, and 147 (10.2%) had nonsimple cysts. Of 283 patients with pancreatic cysts, 158 (55.8%) had only one pancreatic cyst. The number of patients with multiple cysts increased with age after 70 years. Four hundred fifteen (83.8%) cysts were 10 mm in diameter or smaller; 56 (11.3%), 11-20 mm in diameter; and 24 (4.9%), 21 mm in diameter or larger. Sixteen (5.7%) patients with pancreatic cysts had malignant pancreatic tumors, and 75 (26.5%) patients had pancreatitis.

CONCLUSION

The prevalence of pancreatic cysts at single-shot fast SE MR imaging-especially cysts with a diameter smaller than 10 mm-is similar to that of pancreatic cysts at autopsy and higher than that of pancreatic cysts at transabdominal ultrasonography. Prevalence is especially high in patients with pancreatitis.

Simple pancreatic cysts: CT and endosonographic appearances

OBJECTIVE. This report describes the CT and endoscopic sonographic appearance of simple pancreatic cysts in three adults. CONCLUSION. Simple pancreatic cysts are typically an incidental finding in adults who have no history of pancreatic disease. The imaging characteristics of simple pancreatic cysts on CT and endosonography are similar to those of benign cysts.