Pancreatic fine‐needle aspiration cytology in patients < 35‐years of age: A retrospective review of 174 cases spanning a 17‐year period

Pancreatic lesions in young patients are relatively rare and, to our knowledge, the clinical value of pancreatic fine needle aspiration (FNA) in patients < 35 years of age has not been previously established by any other large retrospective studies. All pancreatic endoscopic ultrasound‐guided FNA (EUS‐FNA) cases performed on patients < 35 years of age were identified for a 17‐year period (1994–2010). All FNAs and all available correlating surgical pathology reports were reviewed. There were a total of 174 cases of pancreatic FNA performed on 109 females and 65 males under the age of 35 (range: 8–34, mean: 27 years). The FNA diagnoses included 37 malignant, 114 negative, nine atypia/suspicious, and 14 cases that were nondiagnostic. Of the 37 malignant FNA cases, the diagnoses included 18 pancreatic neuroendocrine tumors (PanNeT), 11 solid pseudopapillary neoplasms (SPN), five adenocarcinomas and three metastatic neoplasms. Histologic follow‐up was available in 22 of the 37 malignant cases diagnosed by FNA, and the diagnosis was confirmed in 21 cases. One pancreatoblastoma was misclassified as SPN on EUS‐FNA. False negative diagnoses were noted in three cases of low‐grade mucinous cystic neoplasm and one case of PanNeT. The most common type of neoplasms diagnosed by EUS‐FNA in patients < 35‐year old is PanNeT, followed by SPN with both tumors accounting for 75% of all the neoplasms encountered in this age group. The sensitivity and specificity for positive cytology in EUS‐FNA of the pancreas to identify malignancy and mucinous neoplasms were 90% and 100%, respectively. Diagn. Cytopathol. 2014;42:297–301. © 2013 Wiley Periodicals, Inc.     

EUS‐guided 22‐gauge fine‐needle aspiration versus core biopsy needle in the evaluation of solid pancreatic neoplasms

Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) is widely used for diagnosis of pancreatic lesions. The Echotip Procore Needle (Wilson‐Cook Medical) is a new 22G fine biopsy needle (FNB) for obtaining core biopsy material at time of EUS. This study aimed to compare the technical and diagnostic performance of conventional FNA and FNB. Thirty‐two patients met the design criteria for this prospective paired cohort study. All lesions sampled were solid (non‐cystic) pancreatic masses by EUS appearance. Patients were randomized to receive FNA or FNB by first attempt. A cytopathologist performed on‐site evaluations. Samples were assessed for accuracy of diagnosis, cellularity, contamination, and sufficiency for ancillary studies. Technical and diagnostic performances were compared. Compared to FNA, there was a statistically significant decreased ability of FNB to achieve a diagnosis (FNA 93.8%, FNB 28.1%, P < 0.001). FNB was diagnostically superior to FNA in 1 of 32 cases. Technical failures were observed in five cases due to resistance to advancement of the FNB needle. Regarding operator perceived ease‐of‐use, FNA outperformed FNB (P < 0.001). Eight cases had insufficient FNB material to survive tissue processing. There was no significant difference in mean specimen cellularity between devices. FNA samples showed an increased amount of contaminant (P = 0.036) but were more sufficient for ancillary studies (P = 0.502). Although deemed comparable to FNA when providing material for cytology, the pledged advantage of FNB acting like a core biopsy needle was not apparent in our series. Additional studies are needed before routine adoption of 22G FNB can be recommended. Diagn. Cytopathol. 2014;42:751–758. © 2014 Wiley Periodicals, Inc.     

Diagnosis of metastatic pancreatic mesenchymal tumors by endoscopic ultrasound‐guided fine‐needle aspiration

Involvement of the pancreas by metastatic sarcoma is rare, and can prove challenging to differentiate from sarcomatoid carcinomas which occur more commonly. The endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) technique has been successfully used for the diagnosis of pancreatic carcinomas whether primary or metastatic, and is now considered the most effective noninvasive method for the identification of pancreatic metastases. However, to date very few reports detail the diagnosis of mesenchymal neoplasms by EUS‐FNA. Herein, we report a series of four patients who underwent EUS‐FNA of the pancreas, where the diagnosis of metastatic sarcoma was made based on morphology and ancillary studies. The cases include metastases of leiomyosarcoma, liposarcoma, alveolar rhabdomyosarcoma, and solitary fibrous tumor. The history of a primary sarcoma of the chest wall, mediastinum, and respectively lower extremity was known for the first three of these patients while in the case of the solitary fibrous tumor a remote history of a paraspinal “hemangiopericytoma” was only elicited after the EUS‐FNA diagnosis was made. We conclude that EUS‐FNA is efficient and accurate in providing a diagnosis of sarcoma, even in patients without a known primary sarcoma, thus allowing institution of therapy without additional biopsies. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.     

EUS‐FNA diagnosis of pancreatic serous cystadenoma with the aid of cell blocks and α‐inhibin immunochemistry: A case series

Serous cystadenoma (SCA) is an uncommon benign pancreatic neoplasm that is most often managed conservatively with follow‐up rather than surgical excision. Therefore, to avoid the serious complications of pancreatic surgery, SCA should be diagnosed accurately at the preoperative level. Preoperative SCA diagnosis requires a multimodal diagnostic approach that includes imaging, cystic fluid biochemical analysis and/or endoscopic ultrasound fine‐needle aspiration (EUS‐FNA). In this brief report, we describe six EUS‐FNA cases from five patients that were reported as “benign, consistent with serous cystadenoma”. Samples were hypocellular, composed of loose clusters and single cuboidal, bland‐looking cells among epithelial sheets representing gastrointestinal contamination. Cell blocks were prepared and all six FNA cases revealed cuboidal cells with a positive α‐inhibin immunophenotype, consistent with a diagnosis of SCA. As EUS‐FNAs of SCA commonly result in non‐diagnostic interpretations, cell block preparations with subsequent immunochemistry can increase their diagnostic accuracy and guide patient management.     

Increased diagnostic yield of endoscopic ultrasound‐guided fine needle aspirates with flow cytometry and immunohistochemistry

Endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) is the most sensitive and specific test for establishing a tissue diagnosis for many gastrointestinal malignancies; however, cytologic morphology alone may not be definitive for subsets of tumors. Our aim was to quantify the impact of the broad application of flow cytometry (FC) and immunohistochemistry (IHC) on EUS‐FNA diagnostic yield. A retrospective chart review was performed on EUS procedures at a tertiary referral, academic medical center. All EUS‐FNA cases performed over a 21‐month period were examined. Of 606 EUS procedures reviewed during the period of study, 264 utilized FNA. After pancreatic cyst cases were excluded, 235 EUS‐FNA cases for 221 patients were selected for analysis. For cases with subsequent histological evaluation, including the subset utilizing FC/IHC, the sensitivity of EUS‐FNA was 89%, specificity was 100%, and accuracy was 91%. One quarter (58/235, 25%) of the tissue specimens underwent further testing by FC/IHC. There were 48 definitive diagnoses made in the subset utilizing FC/IHC. In 20 of the 48 diagnoses (42%), FC/IHC was deemed critical to the diagnosis, and without FC/IHC testing in those cases, the overall sensitivity and accuracy of EUS‐FNA would be reduced to 74 and 77%, respectively. FC/IHC allowed for six diagnoses rarely or not previously described by EUS‐FNA. Application of FC/IHC improves characterization predominantly for nonadenocarcinoma tumor subtypes and may lead to a diagnostic result for tumors not previously characterized by EUS‐FNA. With an adequate tissue sample, broad application of FC/IHC increases the diagnostic yield of EUS‐FNA. Diagn. Cytopathol. 2013;41:1043–1051. © 2012 Wiley Periodicals, Inc.     

Immunocytochemical study of the expression of mesothelin in fine-needle aspiration biopsy specimens of pancreatic adenocarcinoma

Mesothelin is a potential marker of pancreatic adenocarcinoma that was recently identified by serial analysis of gene expression. We evaluated the sensitivity and specificity of mesothelin as a marker of pancreatic adenocarcinoma on destained Papanicolaou (Pap) smears and unstained cellblocks from 28 patients using a monoclonal antibody to mesothelin. Intensity and proportion of staining was semiquantitatively graded on a scale of 1-3, and as 0%, 1 to <10%, 10-50%, or >50%. Positive staining for mesothelin was seen in 64% of the direct smears and in 36% of cell block sections. Focal positivity for mesothelin was noted in benign pancreatic tissue in one of 10 cases. Staining was most often focal (<50% of cells) in both direct smears and cell block sections. The overall sensitivity and specificity of mesothelin as a marker for pancreatic adenocarcinoma were 68% and 90%, respectively. Sensitivity was higher in Pap smears than in cell block sections (64% versus 36%). The presence of occasional mesothelin expression in benign tissue, its very focal expression in malignant tissue may limit the utility of mesothelin as a marker of pancreatic adenocarcinomas in fine-needle aspiration (FNA) specimens.     

Cytologic features of pancreatic adenocarcinoma with “vacuolated cell pattern.” report of a case diagnosed by endoscopic ultrasound‐guided fine‐needle aspiration

The “vacuolated cell pattern” has only been recently described as a distinct morphologic variant of pancreatobiliary adenocarcinoma. Herein, we report the endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) cytologic features of a case of pancreatic adenocarcinoma with “vacuolated cell pattern” occurring in a 60‐year‐old man. The aspirate smears and cell block sections from the EUS‐FNA of a 23.5 mm hypoechoic pancreatic head mass were highly cellular, showing variably‐sized crowded three‐dimensional cell clusters, flat sheets, and numerous highly atypical single cells. The background was bloody and showed necrotic debris, but no discernible mucus. The most striking feature of the aspirate was the presence of numerous very large (20–50 µm) vacuoles, occupying the entire cytoplasm, pushing the nuclei to the side and indenting them, that imparted a cribriform appearance to the sheets of neoplastic cells. The non‐vacuolated neoplastic cells were large, had abundant dense (squamoid) cytoplasm, irregularly contoured hyperchromatic nuclei, and prominent macronucleoli. Histologic evaluation of the pancreatectomy specimen showed a “vacuolated cell pattern” adenocarcinoma composed of poorly formed glands, solid sheets, and infiltrating single cells with pleomorphic nuclei and large cytoplasmic vacuoles. To our knowledge, this is the first report describing the cytologic features of this rather uncommon morphologic variant of pancreatic adenocarcinoma. Recognition of this morphologic variant of pancreatic adenocarcinoma in ESU‐FNA samples allows its differentiation from primary and metastatic signet‐ring cell carcinomas. Diagn. Cytopathol. 2014;42:302–307. © 2014 Wiley Periodicals, Inc.     

The role of endoscopic ultrasound and endoscopic ultrasound-guided fine-needle aspiration in distinguishing pancreatic cystic lesions

Distinguishing mucinous from nonmucinous cystic lesions of the pancreas often constitutes a diagnostic dilemma. The clinical management differs between such lesions; therefore it is important to make an accurate preoperative diagnosis. Various centers have reported conflicting results regarding their ability to detect mucin-producing neoplastic cells and appropriately reach a diagnosis based on endoscopic ultrasound (EUS) guided FNA. The aim of this study is to assess the ability of EUS-FNA cytology to diagnose and differentiate mucinous from nonmucinous pancreatic cystic lesions. We reviewed records of patients who underwent EUS of pancreatic cystic lesions. If FNA was performed and mucinous neoplasm was suspected, aspirate was evaluated for cytomorphology and presence of mucin. FNA results were compared to final histologic diagnosis if surgery was performed.Cytologic diagnosis was provided for 28/30 (93%). By comparing EUS-FNA diagnoses with final surgical pathology, FNA accurately diagnosed in 10/11 cases with sensitivity and specificity for detection of malignancy of 100 and 89, respectively, while the accuracy for identification of mucinous cystic neoplasms was 100%. Our results indicate that in the appropriate clinical and imaging setting, EUS-FNA cytology with analysis for mucin production by tumor cells is an important test in distinguishing pancreatic cystic lesions and guiding further management.     

Combining fine needle aspiration with brushing cytology has improved yields in diagnosing pancreatic ductal adenocarcinoma

The aim of this retrospective study is to evaluate the diagnostic yields of combining fine needle aspiration (FNA) with brushing cytology (BC) in clinical work‐up of pancreatic ductal adenocarcinoma. The study included a total of 97 patients who underwent both FNA and BC along with histologic/clinical follow‐up (F/U). Cytologic diagnoses were categorized as negative for neoplasm (NEG), atypical/favor neoplasm (AN), and suspicious or positive for neoplasm (POS). Based on the cytologic diagnoses, the cohort was divided as follows: 23 had concordant FNA and BC diagnoses of POS/AN, all were neoplasms on F/U; 34 had disconcordant (POS/AN vs. NEG) FNA and BC diagnoses, all but 2 were neoplasms on F/U; The remaining 40 were NEG on both FNA and BC, F/U revealed that 10 were neoplasms and 30 were chronic pancreatitis. Overall, FNA rendered more true positive diagnoses than BC. However, BC but not FNA detected neoplasms in 10 patients. Most of the neoplasms identified on F/U were ductal adenocarcinoma (59 of 65). Diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 69.2, 93.8, 95.7, 60, and 77.3% for FNA alone, 50.8, 100, 100, 50.0, and 67.0% for BC alone, and 84.6, 100, 100, 76.2, and 89.7% for combining FNA with BC. In conclusion, both EUS‐guided FNA and BC are valuable modalities in the preoperative diagnosis of pancreatic ductal adenocarcinoma. When used in combination, the two modalities complement each other and achieve better diagnostic yield in pancreatic ductal adenocarcinoma than either FNA or BC alone. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.     

Biomarkers in Diagnosis of pancreatic carcinoma in fine-needle aspirates

This study was undertaken to determine whether recently identified proteins could be translated to clinical practice as markers to distinguish pancreatic adenocarcinoma from chronic pancreatitis on fine-needle aspirate (FNA) samples. Resected pancreatic tissue sections (n = 40) and FNA samples (n = 65) were stained for clusterin-beta, MUC4, survivin, and mesothelin. For each biomarker, the staining patterns in adenocarcinoma and in reactive ductal epithelium were evaluated and compared. Clusterin-beta stained reactive ductal epithelium significantly more frequently than pancreatic adenocarcinoma (P < .001). In comparison, MUC4 and mesothelin were expressed more frequently in pancreatic adenocarcinoma on tissue sections. Positive staining for MUC4 (91% vs 0%; P < .001) and mesothelin (62% vs 0%; P = .01) and absence of staining for clusterin-beta (90% vs 7%; P < .001) were noted significantly more frequently in adenocarcinoma cells than in reactive cells in FNA samples. Clusterin-beta and MUC4 can help distinguish reactive ductal epithelial cells from the cells of pancreatic adenocarcinoma in FNA samples.     

Primary pancreatic leiomyosarcoma with metastasis to the liver diagnosed by endoscopic ultrasound‐guided fine needle aspiration and fine needle biopsy

Primary pancreatic leiomyosarcomas are rare tumors of the pancreas that are usually diagnosed after resection or by biopsy. One case in the literature has utilized endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) cytology. We report a second case of a primary pancreatic leiomyosarcoma that yielded diagnostic material on EUS‐FNA cytology. A 72‐year‐old female presented with 3–4 months of abdominal pain. A CT scan showed a large heterogeneous, lobulated pancreatic head and uncinate mass and multiple hypoattenuating liver lesions. An EUS‐FNA was performed on one of the liver lesions with a 25‐gauge needle, yielding an adequate sample with lesional cells. The initial read was a spindle cell neoplasm. A subsequent endoscopic ultrasound‐guided fine needle biopsy with a 22‐gauge needle was performed on the pancreatic head mass to rule out two primaries and to provide tissue for a mitotic index in the case of gastrointestinal tumor. Both the cell block of the EUS‐FNA and the core biopsy were equally cellular and showed interlacing spindle cells that stained positive for SMA and negative for DOG‐1, CD 117, and CD34. In addition, the core biopsy of the pancreas stained positive for Desmin. A diagnosis of a primary pancreatic leiomyosarcoma was made and the patient was started on systemic chemotherapy. Primary pancreatic leiomyosarcomas are rare pancreatic tumors that may yield diagnostic material by EUS‐FNA with a 25‐gauge needle. Diagn. Cytopathol. 2016;44:1070–1073. © 2016 Wiley Periodicals, Inc.     

Utility of endoscopic ultrasound‐guided fine‐needle aspiration in the diagnosis and staging of colorectal carcinoma

The objective of this study is to assess the utility of endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) in the diagnosis and staging of colorectal cancer. The study includes patients who underwent EUS‐FNA at our institution for staging of colorectal carcinoma or for evaluation peri‐rectal masses or distal metastases from August 2000 to November 2010. We assessed the frequency with which EUS‐FNA procedure confirms the diagnosis of malignancy and the percent of cases in which it modifies staging of colorectal carcinoma. Using histology as a reference standard, we also assessed the diagnostic performance. We identified 79 cases of EUS‐FNA from 77 patients, mean (SD) age of 60 (12.5), 44 males. Twenty‐seven (34%) aspirates were from patients with primary rectal/peri‐rectal masses, 15 (19%) were from patients with suspected regional lymph node metastasis, and 37 (47%) were cases of suspected of distal metastasis. All lesions were clinically suspicious for primary or metastatic colorectal carcinoma. On cytologic examinations, 43 (54%) cases were confirmed as malignant, 6 (8%) were benign neoplasms, 4 (5%) were suspicious for malignant neoplasm, 2 (3%) showed atypical cells, and the rest 24 (30%) were negative for neoplasms. Fourteen of 27 (52%) of the local rectal masses were confirmed as colorectal carcinoma. Eleven of 15 (73%) regional lymph nodes were positive for metastasis—all, but two of these metastases, were of colorectal origin. Twenty of 37(54%) distal lesions were metastatic neoplasms and 15 of those were colorectal in origin. Diagnosis of primary colorectal carcinoma was confirmed in 52% of the clinically suspicious primary lesions and in 42% regional or distal metastatic lesions. Using histology as a reference standard in 27 of 79 (29%) cases, we calculated an overall sensitivity, specificity, and positive and negative predictive values (C.I) of EUS‐FNA of 89% (74–100%), 79% (50–100%) 89% (74–100%), and 79% (51–100%). EUS‐FNA is useful for assessing primary and metastatic colorectal lesion. This technique improves staging of suspected nodal or distant metastases. Diagn. Cytopathol. 2013;41:1031–1037. © 2011 Wiley Periodicals, Inc.     

Metastatic tonsillar squamous cell carcinoma masquerading as a pancreatic cystic tumor and diagnosed by EUS‐guided FNA

Metastatic carcinoma to the pancreas is uncommon and head and neck squamous carcinoma metastatic to the pancreas is extremely rare. Metastatic squamous cell carcinoma to the pancreas presents a unique diagnostic challenge: in addition to mimicking the rare primary squamous cell carcinoma of the pancreas based on cytologic, histologic, and immunohistochemical features, it may be mistaken for a cystic neoplasm of the pancreas because of its high predilection for cystic degeneration in metastatic sites. Herein, we report a case of tonsillar squamous cell carcinoma with a cystic pancreatic metastasis diagnosed by ultrasound‐guided fine needle aspiration biopsy (EUS‐FNA). This represents a third reported case of metastatic squamous cell carcinoma to the pancreas from the head and neck region. Metastatic squamous cell carcinoma should be considered in the differential diagnosis of EUS‐FNA during evaluation of pancreatic cystic lesion.     

Endoscopic ultrasonography‐guided fine‐needle aspiration for diagnosing upper gastrointestinal submucosal lesions: A prospective study of 50 cases

The objective was to assess EUS‐FNA for diagnosing intramural upper GI tract lesions. The subjects were 50 patients (21M/29F) with upper GI submucosal lesions who underwent EUS‐FNA at a referral center for GI system over a 12‐month period. All cases were followed for 1 year after initial EUS‐FNA. Cytologic diagnoses were categorized as benign, malignant, suspicious for malignancy, mesenchymal tumor, endocrine tumor, or nondiagnostic. All tumors were assessed for various cytomorphologic features. The accuracy of the initial FNA diagnoses was evaluated for each patient who also underwent subsequent histopathological examination of a core biopsy and/or surgical biopsy/resection material of the same lesion. According to the site of the lesions; while 84% of all esophageal lesions were diagnosed as mesenchymal; 67% of all gastric lesions were mesenchymal. The sole lesion was nonmesenchymal (benign cyst) in duodenum. The sensitivity, specificity, positive and negative predictive values, and accuracy of EUS‐FNA for diagnosing submucosal mesenchymal tumors of the upper GI tract were 82.9, 73.3, 87.9, 64.7, and 80%, respectively. The corresponding values for nonmesenchymal lesions were 100, 85.7, 80, 100, and 90.9%. Our experience confirms that EUS‐FNA is an extremely valuable tool for diagnosing submucosal lesions of the upper GI, and is particularly useful in cases where endoscopic forceps biopsy does not lead to diagnosis. Optimal results can be yielded by a close working relationship between the gastroenterologist and pathologist. Diagn. Cytopathol. 2011. © 2010 Wiley‐Liss, Inc.     

Primary pancreatic diffuse large B‐cell lymphoma diagnosed by endoscopic ultrasound guided FNAC: A rare entity

Primary pancreatic lymphoma (PPL) is an uncommon neoplasm which can clinico‐radiologically mimic carcinoma. But the management of these patients differs from that of a carcinoma. Endoscopic ultrasound (EUS) guided fine‐needle aspiration (FNA) serves as a potential tool to identify pancreatic lymphomas and thus prevent an invasive diagnostic test. This case report describes the presentation and diagnosis of primary pancreatic lymphoma. A 37‐year‐old female presented with nausea, vomiting with signs of icterus and elevated liver function test and Bilirubin. Abdominal computed tomography (CT) revealed a hypodense lesion in the head of the pancreas. EUS guided FNA was performed and cytological material was collected. The lesion was diagnosed as Non‐Hodgkin Lymphoma (NHL) and subtyped as diffuse large B‐cell lymphoma‐germinal centre (DLBCL‐GCB) base on immunohistochemistry on cell block. The patient was started on rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (RCHOP) regimen. EUS guided FNA along with ROSE, cell bock, and immunocytochemistry helps in the diagnosis of primary pancreatic lymphoma.     

Perivascular Epithelioid Cell Tumor (PEComa) of Pancreas Diagnosed Preoperatively by Endoscopic Ultrasound‐Guided Fine‐Needle Aspiration

Perivascular epithelioid cell tumors (PEComas) of the pancreas are extremely rare mesenchymal tumors and to our knowledge, only 17 cases have been reported in the English literature to date. We report our experience with a new case of primary pancreatic PEComa diagnosed preoperatively by endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) complemented by tissue cell block and immunohistochemistry. The patient was a 54‐year‐old female whose chief complaint was intermittent severe right upper quadrant abdominal pain. Computed‐tomography (CT) imaging revealed a mass between the head and the body of the pancreas. EUS‐FNA smear preparation was obtained but was nondiagnostic. However, examination of the tissue cell block showed sheets of epithelioid cells with abundant eosinophilic cytoplasm and immunohistochemistry studies revealed positivity for both melanocytic (HMB‐45 and Melan‐A) and smooth muscle markers (actin and desmin). A diagnosis of PEComa was made and an uncomplicated middle pancreatectomy was performed. Our case and review of the literature demonstrates that EUS‐FNA complemented with tissue cell block increases cellular yield, improved preoperative diagnostic accuracy, and may assist the surgeon in planning conservative surgical management. Diagn. Cytopathol. 2017;45:59–65. © 2016 Wiley Periodicals, Inc.     

Endoscopic ultrasound‐guided fine‐needle aspiration diagnosis of merkel cell carcinoma metastatic to the pancreas

Merkel cell carcinoma (MCC) is a rare and highly aggressive primary neuroendocrine carcinoma of the skin with a high propensity for local, regional, and distant spread. Distant metastasis of MCC to the pancreas is uncommonly seen and may impose a diagnostic challenge cytologically. Here we report a case of MCC with pancreatic metastasis, which was diagnosed by endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA). The aspirates revealed both single and clustered epithelial cells with scant cytoplasm and round nuclei with stippled chromatin and inconspicuous nucleoli. Immunocytochemically, the tumor cells were positive for CK20, synaptophysin, CD56, and CD117. The neoplastic cells were also identified by flow cytometry as non‐hematopoietic cells which were positive for CD56 and negative for CD45. To our knowledge, this is only the second case report of MCC metastatic to the pancreas diagnosed by EUS‐FNA. There have been several reports of MCC metastatic to the pancreas diagnosed only at the time of surgical resection. However, a preoperative diagnosis allows for appropriate management while sparing a patient the morbidity of unnecessary procedures. Diagn. Cytopathol. 2014;247–252. © 2012 Wiley Periodicals, Inc.     

Intrapancreatic schwannoma diagnosed by endoscopic ultrasound‐guided fine‐needle aspiration cytology

Schwannoma is a tumor of neuro‐ectodermal origin, usually occuring in the head and neck and extremities. A retroperitoneal, and particularly intra‐pancreatic presentation is very rare, and poses a clinical and diagnostic challenge. We report a case of a male patient who underwent an Endoscopic Ultrasound‐guided Fine Needle Aspiration (EUS‐FNA) biopsy of a hypoechoic, intra‐pancreatic mass. The onsite cytological evaluation was consistent with a spindle cell neoplasm. Further evaluation, aided by immunohistochemical stains, defined the mass as a Schwannoma. The patient then underwent a pancreaticoduodenectomy and the histopathological diagnosis of the surgical specimen confirmed the cytological diagnosis. To our knowledge, this is the first report of intra‐pancreatic Schwannoma diagnosed preoperatively by EUS‐FNA cytology. Diagn. Cytopathol. 2009. © 2008 Wiley‐Liss, Inc.