review of literature on clinical pancreatology - The Pancreapedia

diagnosis, and after definitive diagnosis, patients with lesions that are small andasymptomatic may be followed with serial imaging. If definitive diagnosis cannot be made orif the patient is symptomatic, resection is warranted. In addition, large (> 4 cm) serouscystadenomas should be resected in appropriate surgical candidates given their propensityfor growth and developing symptoms [599].Many patients with benign serous cystadenoma (SCA) <strong>of</strong> the pancreas will undergo resectionbecause <strong>of</strong> the inability to reliably discriminate between SCA and premalignant mucinouscysts (intraductal papillary mucinous neoplasm – IPMN – mucinous cystic neoplasm –MCN]). Cyst fluid from patients with SCA (n=15), non main-duct and noninvasive IPMN(n=32), and noninvasive MCN (n=12) was aspirated at the time <strong>of</strong> operative resection andanalyzed. Commercially available and custom designed multiplex assays (Luminex) wereperformed using a biomarker panel developed for pancreatic cancer. Differential proteinexpression (fluorescence intensity, FI) was compared between the 3 groups for each protein.Unsupervised sample clustering (hierarchical clustering) and supervised sampleclassification (prediction analysis for microarrays – PAM) was then performed. Significantdifferential protein expression was identified between SCA and IPMN (34/51 proteins, 67 %)and between SCA and MCN (13/51 proteins, 25 %). The majority <strong>of</strong> proteins were downregulatedin IPMN and MCN compared with SCA. The only proteins significantlyoverexpressed in the cyst fluid <strong>of</strong> patients with mucinous cysts were CEA (median FI: IPMN11.4, MCN 13.0, SCA 5.3) and CA72.4 (median FI: IPMN 10.4, MCN 10.5, SCA 9.9).Unsupervised cluster analysis demonstrated distinct clustering <strong>of</strong> SCA and IPMN with somecross-over between MCN. Supervised sample classification with 14 proteins had an overallaccuracy rate <strong>of</strong> 92 percent between SCA and IPMN. In this study differential cyst fluidprotein expression was observed between SCA and IPMN for the majority <strong>of</strong> proteinsassessed and multimarker sample classification accurately discriminated between SCA andIPMN in 92 percent <strong>of</strong> patients [600].Diffuse serous cystadenomas <strong>of</strong> the pancreas are extremely rare, with only 8 cases reportedpreviously, and have been associated with neuroendocrine tumors in only two patients.Some have been seen in von Hippel-Lindau disease. The management <strong>of</strong> these tumorsposes a challenge due to their rarity and uncertain malignant potential. It was reported acase <strong>of</strong> diffuse serous cystadenoma associated with neuroendocrine carcinoma in a 35-yearoldwoman. A 35-year-old woman with mild abdominal pain was diagnosed as having acystic pancreatic mass on ultrasonography. On contrast-enhanced CT scan, MRI and MRCPimaging, a spongy lesion was found to replace the entire pancreas, and was diagnosed asdiffuse serous cystadenoma. Serum biochemistry for amylase, lipase, CA 19-9 and CEA wasnormal. Screening for retinal and CNS lesions was also unremarkable. A totalpancreatectomy was performed, and the patient recovered well. Histopathologicalexamination <strong>of</strong> the specimen revealed microcysts and macrocysts replacing the entirepancreas, the largest being 3.5 cm. The cysts were lined with a single layer <strong>of</strong> cuboidal t<strong>of</strong>lattened cells. An endocrine tumor abutting the cystic component was found, havingneoplastic cells in a trabecular pattern. Metastasis <strong>of</strong> the neuroendocrine component wasseen in the adherent lymph nodes. A diagnosis <strong>of</strong> diffuse serous cystadenoma associatedwith neuroendocrine carcinoma was made. It was concluded that diffuse serouscystadenomas <strong>of</strong> the pancreas are extremely rare tumors. In young patients, they mayharbour associated malignancy, and may be the first presentation <strong>of</strong> von Hippel-Lindaudisease. Aggressive surgical resection with long-term follow-up may be worthwhile in thisgroup <strong>of</strong> patients [601].Serous microcystic adenomaThe diagnosis <strong>of</strong> serous microcystic adenoma (SMA) is usually straightforward. For smallbiopsies and/or unusual variants, the differential diagnosis includes other pancreatic or