Immunohistochemical Antibody Panel for the Differential Diagnosis of Pancreatic Ductal Carcinoma From Gastrointestinal Contamination and Benign Pancreatic Duct Epithelium in Endoscopic Ultrasound-Guided Fine-Needle Aspiration.

OBJECTIVES: The diagnosis of pancreatic ductal adenocarcinoma (PDAC) by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) can be challenging to distinguish tumor cells from benign epithelium (BE). The aim of the present study was to set a minimal antibody panel to differentiate PDAC from contaminated BE in EUS-FNA specimens. METHODS: Immunohistochemistry using claudin 4, EZH2, Ki-67, maspin, p53, and S100P was performed on tissue microarray sections containing 53 PDACs and 33 BE as well as cell blocks of EUS-FNA including 53 PDACs and 22 BE. The positive rate was scored as 0 to 4+. The receiver operating characteristic curve was applied to determine a cutoff point, and the Classification And Regression Trees method was used to obtain a classification tree of the best panel. RESULTS: The cutoff point was 1+ for claudin 4, EZH2, Ki-67, p53, and S100P and 2+ for maspin. All BE scored 0 for p53. The classification tree revealed using p53, S100P, and claudin 4 was the most powerful. The sensitivity and specificity of the tree were 96.2% and 100% in tissue microarrays and 100% and 95.5% in EUS-FNA, respectively. CONCLUSIONS: The classification tree using p53, S100P, and claudin 4 seems to successfully distinguish PDAC from the accompanying BE.

A case of xanthogranulomatous cholecystitis suspected to be adenocarcinoma based on the intraoperative peritoneal washing cytology.

INTRODUCTION: Xanthogranulomatous cholecystitis (XGC) is a variant of chronic cholecystitis. XGC remains difficult to distinguish from gallbladder cancer radiologically and macroscopically. PRESENTATION OF CASE: A 63-year-old female was referred to our hospital because of a gallbladder tumor. Abdominal CT and MRI revealed a thickened gallbladder that had an obscure border with the transverse colon. FDG-PET showed a high uptake of FDG in the gallbladder. Therefore, under the preoperative diagnosis of an advanced gallbladder cancer with invasion to the transverse colon, a laparotomy was performed. Because adenocarcinoma was suspected based on the intraoperative peritoneal washing cytology (IPWC), cholecystectomy and partial transverse colectomy were performed instead of radial surgery. However, the case was proven to be XGC with no malignant cells after the operation. DISCUSSION: In patients with gallbladder cancer who underwent surgery in our institute from 2000 to 2009, the prognosis after the operation of patients with only positive IPWC tended to be better than that of patients with definitive peritoneal disseminated nodules. It is true that in some cases, it is difficult to differentiate XGC from gallbladder carcinoma pre- and intra-operatively. CONCLUSION: Surgical procedures should be selected based on the facts that there are long-term survivors with gallbladder cancer diagnosed with positive IPWC, and that some patients with XGC are initially diagnosed to have carcinoma by IPWC, as was seen in our case.

[Utility of rapid on-site cytology in endoscopic ultrasonography-guided fine needle aspiration of pancreatic masses].

BACKGROUND: Endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) is a safe and effective method for obtaining samples for cytological diagnosis. Pancreatic cancer is extremely serious and often extremely aggressive, so early detection and diagnosis is important. Therefore, we actively perform EUS FNA for pathological diagnosis of cancer of digestive organs, especially the pancreas. MATERIALS AND METHODS: EUS-FNA was performed in 67 patients (39 male, 28 female, median age 63.3 years) from January 2007 to December 2010 in Kyoto University Hospital. To eliminate both quantitatively and qualitatively inadequate samples, we performed EUS-FNA with rapid on-site cytology. Two squash preparations of the collected cells from biopsy were retrieved. One was stained on-site with Giemsa for rapid cytology to evaluate the quantity and quality of the cell collection. If necessary, second or third trials were carried out to obtain appropriate samples for final cytology diagnosis. The other was wet-fixed and used for Papanicolaou staining. RESULTS: All 11 cases of inflammatory disease were diagnosed as negative on cytology. Solid-pseudopapillary neoplasm (1 case) and Endocrine neoplasms (3 cases) were correctly diagnosed on cytology. In pancreatic cancer, 49 of 52 cases (94%) were diagnosed as positive, but 3 cases (6%) were false-negative on cytology. The number of centesis for sampling was once in 21 cases, twice in 26 cases and more than twice in 20 cases. In this study of EUS-FNA, sensitivity was 94% and specificity was 100%. CONCLUSION: Results of our examination suggest that the combination of EUS-FNA and rapid on-site cytology is a highly specific and sensitive test for detection of pancreatic cancer, and may contribute to reduce excessive centesis.