Pancreatic Cyst Lesions (PCLs) are frequently diagnosed in radiologic imaging tests and can be classified as benign, premalignant and malignant. Their correct stratification is essential and has significant implications for the patient. The objective of the study was to determine the clinical and analytical characteristics that can help in their differential diagnosis.

This observational retrospective study included patients with PCLs diagnosed by endoscopic ultrasound from 2011 to 2023. Data collected included age, sex, personal history, treatments, toxic habits, family history of cancer, body mass index, and radiological and serological findings. The following intra-cyst levels were gathered: glucose, amylase, lipase, CEA and CA19.9.

271 patients with PCLs were included, 93 (35%) of them were benign, 55 (20%) were premalignant, and 123 (45%) malignant. Serous cystadenomas were the most common benign lesion in 71 (76%) patients. Within the premalignant group, intraductal papillary mucinous neoplasms (IPMNs) were the most common in 85% (47) patients. Cystic adenocarcinoma was the most prevalent malignant PCLs in 102 (83%) patients. Intra-cystic CEA value was the only parameter able to differentiate benign from malignant/premalignant lesions. Thirty (11%) patients underwent surgery with a final diagnosis of a malignant lesion in 13 (43%) patients, premalignant lesions in 5 (23%) (4 IPMNs and 1 mucinous cystadenoma) and benign cysts in 12 (40%). Five (38%) of the 13 malignant lesions were diagnosed at stages III/IV.

Intra-cyst CEA values can help us to classify premalignant PCNs. However, additional biomarkers and clinical parameters are required to better discriminate patients at the time of PCLs detection.

Cystic neoplasms of the pancreas are a heterogeneous group of pancreatic tumors that vary in pathophysiology, malignant potential, clinical course, and outcomes. Their management is heavily predicated on establishing an accurate diagnosis. This can be particularly challenging, but can often be achieved by a thorough history and physical examination combined with high-quality, thin-slice computed tomography, although additional diagnostic tools may be required. Once the diagnosis is established, treatment can range from simple observation to total pancreatectomy. This decision rests on a clear and complete understanding of each disease process in the context of the patient's age and comorbidities. This article reviews the most common cystic neoplasms of the pancreas, focusing on their diagnosis and management.

With more widespread use of imaging, cystic neoplasms of the pancreas are being diagnosed with increased frequency. Serous cystadenomas are the most common type of cystic neoplasm of the pancreas and have a natural history and malignant potential different than that of other cystic neoplasms. Although characteristic findings on imaging may be supportive, definitive diagnosis of these lesions often cannot be made by imaging alone. Endoscopic ultrasound with fine needle aspiration and cyst aspiration may facilitate the diagnosis, and after definitive diagnosis, patients with lesions that are small and asymptomatic may be followed with serial imaging. If definitive diagnosis cannot be made or if the patient is symptomatic, resection is warranted. In addition, large (> 4 cm) serous cystadenomas should be resected in appropriate surgical candidates given their propensity for growth and developing symptoms.

The purpose of this work was to evaluate the capabilities of CT to accurately characterize cystic tumors of the pancreas.

Two observers retrospectively evaluated the CT exams of 100 cystic masses of the pancreas, with pathological confirmation. The two observers, blinded about clinical information and the final diagnosis, tried to categorize the lesions according to well established morphologic features. Statistical analysis was performed to measure the agreement between each radiologist and the consensus diagnosis and to evaluate the usefulness of certain CT findings in differentiating one type of cystic pancreatic neoplasm from another.

Serous cystadenoma was better diagnosed by CT [Youden misclassification index (Ymi) = 0.72] than mucinous cystic tumor (Ymi = 0.44) and solid pseudopapillary tumor (cystic variant) (Ymi = 0.47).

As patients with previous history of pancreatitis were excluded from the study, CT findings allowed correct characterization of only 60% of cystic pancreatic masses. Among the remaining 40%, 15-20% of the wrong diagnoses could not be corrected by means of CT, given the patterns shown by the tumors. In 20-25% of the cases, a nonspecific diagnosis of cystic mass was made.

To review the features of patients with benign and malignant cystadenomas of the pancreas, focusing on preoperative diagnostic accuracy and long-term outcome, especially for nonoperated serous cystadenomas and resected cystadenocarcinomas.

Serous cystadenomas (SCAs) are benign tumors. Mucinous cystic neoplasms should be resected because of the risk of malignant progression. A correct preoperative diagnosis of tumor type is based on morphologic criteria. Despite the high quality of recent imaging procedures, the diagnosis frequently remains uncertain. Invasive investigations such as endosonography and diagnostic aspiration of cystic fluid may be helpful, but their assessment is limited to small series. The management of typical SCA may require resection or observation. Survival after pancreatic resection seems better for cystadenocarcinomas (MCACs) than for ductal adenocarcinomas of the pancreas.

Three hundred ninety-eight cases of cystadenomas of the pancreas were collected between 1984 and 1996 in 73 institutions of the French Surgical Association. Clinical presentation, radiologic evaluation, and surgical procedures were analyzed for 144 operated SCAs, 150 mucinous cystadenomas (MCAs), and 78 MCACs. The outcome of 372 operated patients and 26 nonoperated patients with SCA was analyzed.

Cystadenomas represented 76% of all primary pancreatic cystic tumors (398/522). An asymptomatic tumor was discovered in 32% of patients with SCA, 26% of those with MCA, and 13% of those with MCAC. The tumor was located in the head or uncinate process of the pancreas in 38% of those with SCA, 27% of those with MCA, and 49% of those with MCAC. A communication between the cyst and pancreatic duct was discovered in 0.6% of those with SCA, 6% of those with MCA, and 10% of those with MCAC. The main investigations were ultrasonography and computed tomography (94% for SCA, MCA, and MCAC), endosonography (34%, 28%, and 22% for SCA, MCA, and MCAC respectively), endoscopic retrograde cholangiopancreatography (16%, 14%, 22%), and cyst fluid analysis (22%, 31%, 35%). An accurate preoperative diagnosis of tumor type was proposed for 20% of those with SCA (144 cases), 30% of those with MCA, and 29% of those with MCAC. An atypical unilocular macrocyst was observed in 10% of SCA cases. The most common misdiagnosis for mucinous cystic tumors was pseudocyst (9% of MCAs, 15% of MCACs). Intraoperative frozen sections (126 cases) allowed a diagnosis according to definitive histologic examination in 50% of those with SCA and MCA and 62% of those with MCAC. For management, 93% of patients underwent surgery. Nonoperated patients (7%) had exclusively typical SCA. A complete cyst excision was performed in 94% of benign cystadenomas, with an operative mortality rate of 2% for SCA and 1.4% for MCA. Resection was possible in 74% of cases of MCAC. Mean follow-up of 26 patients with nonresected SCAs was 38 months, and no patients required surgery. For resected MCACs, the actuarial 5-year survival rate was 63%.

Spiral computed tomography is the examination of choice for a correct prediction of tumor type. Endosonography may be useful to detect the morphologic criteria of small tumors. Diagnostic aspiration of the cyst allows differentiation of the macrocystic form of SCA (10% of cases) and the unilocular type of mucinous cystic neoplasm from a pseudocyst. Surgical resection should be performed for symptomatic SCAs, all mucinous cystic neoplasms, and cystic tumors that are not clearly defined. Conservative management is wholly justified for a well-documented SCA with no symptoms. An extensive resection is warranted for MCAC because the 5-year survival rate may exceed 60%.

To evaluate clinical parameters, presurgical diagnostic tests, histologic findings, and the presence of K-ras oncogene mutations in cystic tumors of the pancreas to determine which best predict malignancy.

Because presurgical, intraoperative, and final pathologic differentiation is difficult in cystic tumors of the pancreas, it would be a major benefit to identify markers that accurately predict malignancy in these rare tumors. The role of K-ras oncogene mutations as an indicator of malignancy has not been determined in these tumors.

Nineteen patients with cystic tumors of the pancreas were evaluated, including K-ras mutation analysis based on polymerase chain reaction and restriction digestion assays and direct DNA sequencing, to screen for parameters that accurately predict malignancy.

All malignant cystic pancreatic tumors (five cystadenocarcinomas and three mucin-producing adenocarcinomas) harbored K-ras mutations at codon 12 or 13. K-ras mutations were also detected in the percutaneous fine-needle aspirates of two of these patients. In contrast, none of nine benign cystadenomas or the solid-papillary neoplasm had K-ras mutations. None of the patients with a benign tumor carrying K-ras wild-type sequences developed recurrent disease after a mean follow-up of 50 months. Seven of the 8 malignant cystic pancreatic tumors, but none of the 11 benign tumors, showed dilatation of the main pancreatic duct on computed tomography or endoscopic retrograde cholangiopancreatography.

K-ras mutation analysis seems to be a powerful tool to determine the malignant potential of cystic pancreatic tumors before and after surgery. Dilatation of the main pancreatic duct on computed tomography or endoscopic retrograde cholangiopancreatography is highly suggestive for malignancy in these rare tumors.

Twenty-one patients with pancreatic cystic neoplasms (PCNs) were treated from 1970 to 1991. Their mean age was 54 years (range: 30 to 78 years), and 15 (71%) were women. Symptoms were present for a mean of 18 months (range: 5 to 60 months) and included pain (95%), abdominal mass (52%), weight loss (38%), and jaundice (14%). Nine patients had had previous operations and were either misdiagnosed or incorrectly treated; another seven patients had preoperative misdiagnoses of pseudocysts. There were six (29%) serous cystadenomas and two (10%) mucinous cystadenomas. These were treated by excision (n = 2), distal pancreatectomy (n = 5), or pancreatoduodenectomy (n = 1). No recurrence or malignant degeneration occurred during the mean follow-up of 9 years (range: 1 to 19 years). There were 13 (62%) patients with mucinous cystadenocarcinomas. Of these 13 patients, 3 had unresectable tumors, underwent palliative procedures, and died at 4, 7, and 9 months, respectively. Ten patients underwent pancreatoduodenectomy (n = 4), distal (n = 4) pancreatectomy, or total (n = 2) pancreatectomy: 1 died of recurrence (survival: 8 months), and the remaining 9 patients had a mean survival of 6 years (range: 2 to 20 years) without recurrence. This experience suggests that patients with PCNs have a good prognosis and are curable if the cysts are diagnosed early and completely resected.