Pancreatic Cystic Neoplasm

Cystic lesions of the pancreas are a rare entity, and few reports have described their natural history in children. A previously published report described a 9-year-old boy with an acinar cell cystadenoma, discovered during a laparoscopic appendectomy. Initially asymptomatic and followed by serial MRI, this patient presented to our institution several years later with chronic obstructive symptoms that required surgical intervention. Planning for resection included multidisciplinary input from the genetics and endocrinology services. Initially, a partial pancreatic resection was performed in an attempt to preserve normal pancreatic tissue and islet cell function. Progression of the cystic disease and recurrent obstruction necessitated further surgical intervention. Here we present the updated clinical course and outcome of a 12-year-old boy who underwent a total pancreaticoduodenectomy for a symptomatic acinar cell cystadenoma.

Pseudopapillary tumors (PPT) of the pancreas are very rare, comprising 0.3–2.7% of all pancreatic tumors, and they occur mostly in young women. Generally, they are benign, but in rare cases they can enlarge, invade adjacent organs, and metastasize distantly. Radiological assessments and biochemical markers are important for diagnosing tumor characteristics. The main treatment is tumor resection.

An 18-year-old female was referred to our department suffering from abdominal discomfort and upper quadrant abdominal pain. Abdominal computed tomography (CT) revealed a 6- × 5-cm mass between the pancreatic head and right adrenal gland (Fig. 1). The histological assessment was a solid PPT of the pancreas with intact surgical borders.

PPT are very rare, comprising approximately 5% of cystic pancreatic tumors and ∼1% of exocrine pancreatic neoplasms and present mainly during the second and third decades of life. PPTs are usually indolent tumors. As such, they tend to produce vague nonspecific symptoms or may be detected incidentally on imaging. Complete surgical resection (R0) is the most effective therapy for PPT.

Although PPT is a very rare, benign tumor, it has the potential to metastasize to adjacent and distant organs. Consequently, they should be detected early, so that they can be treated surgically before malignant conversion.

This report contains clinically oriented guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms in patients fit for treatment. The statements were elaborated by working groups of experts by searching and analysing the literature, and then underwent a consensus process using a modified Delphi procedure. The statements report recommendations regarding the most appropriate use and timing of various imaging techniques and of endoscopic ultrasound, the role of circulating and intracystic markers and the pathologic evaluation for the diagnosis and follow-up of cystic pancreatic neoplasms.

To explore a simple and reliable non-invasive distinguishing system for the pre-operative evaluation of malignancy in pancreatic cystic neoplasm (PCN).

This study first enrolled an observation cohort of 102 consecutive PCN patients. Demographic information, results of laboratory examinations, and computed tomography (CT) presentations were recorded and analyzed to achieve a distinguishing model/system for malignancy. A group of 21 patients was then included to validate the model/system prospectively.

Based on the 11 malignancy-related features identified by univariate analysis, a distinguishing model for malignancy in PCN was established by multivariate analysis: PCN malignant score = 2.967 × elevated fasting blood glucose (FBG) (≥6.16 mmol/L) ± 4.496 × asymmetrically thickened wall (or mural nodules ≥ 4 mm) ± 1.679 × septum thickening (≥2 mm) − 5.134. With the optimal cut-off value selected as −2.8 in reference to the Youden index, the proposed system for malignant PCN was established: septum thickening (>2 mm), asymmetrically thickened wall (or mural nodules > 4 mm), or elevated FBG (>6.16 mmol/L, accompanying commonly known malignant signs), the presence of at least one of these 3 features indicated malignancy in PCN. The accuracy, sensitivity and specificity of this system were 81.4%, 95.8% and 76.9%, respectively. MRI was performed on 32 patients, making correct prediction of malignancy explicitly in only 68.8% (22/32). The subsequent prospective validation study showed that the proposed distinguishing system had a predictive accuracy of 85.7% (18/21). Moreover, a higher model score, or aggregation of the features in the proposed system, indicated a higher grade of malignancy (carcinoma) in PCN.

Elevated FBG (>6.16 mmol/L), asymmetrically thickened wall (or mural nodules > 4 mm) and septum thickening (>2 mm) are of great value in differentiating the malignancy in PCN. The developed distinguishing system is reliable in the diagnosis of malignant PCN.

Primary pancreatic cystic neoplasms are being recognized with increasing frequency due to modern imaging techniques. In addition to the more common cystic neoplasms—serous cystadenoma, primary mucinous cystic neoplasm, and intraductal papillary mucinous neoplasm—there are many other less common neoplasms that appear as cystic lesions. These cystic neoplasms include solid pseudopapillary neoplasm of the pancreas (the most common rare cystic neoplasm), cystic neuroendocrine neoplasm, cystic degeneration of otherwise solid neoplasms, and then the exceedingly rare cystic acinar cell neoplasm, intraductal tubular neoplasm, angiomatous neoplasm, lymphoepithelial cysts (not true neoplasms), and few others of mesenchymal origin. While quite rare, the pancreatic surgeon should at the least consider these unusual neoplasms in the differential diagnosis of potentially benign or malignant cystic lesions of the pancreas. Moreover, each of these unusual neoplasms has their own natural history/tumor biology and may require a different level of operative aggressiveness to obtain the optimal outcome.