Fine needle aspiration cytology of endocrine neoplasms of the pancreas. Morphologic and immunocytochemical findings in 20 cases

Ancillary Studies, Including Immunohistochemistry and Molecular Studies, in Pancreatic Cytology

Fine-needle aspiration biopsy of the pancreas is indicated for sampling of solid and cystic masses. Preoperative cytologic diagnosis of pancreatic ductal adenocarcinoma and cystic lesions on cytology can be problematic, and ancillary studies may help confirm diagnosis. Ancillary studies in pancreatic cytology include special stains, immunohistochemistry, mutational analyses of specific genes, cyst fluid analysis of tumor markers and enzymes, and, in some instances, flow cytometry. Proteomics, microRNA sequencing, and whole-exome gene sequencing have been used to illustrate the progression of pancreatic neoplasms and identify key diagnostic markers. This article summarizes recent literature on ancillary studies in pancreatic fine-needle aspiration samples.

Cytologic features of lipid-rich variant of pancreatic endocrine tumor-report of two cases with literature review

Pancreatic endocrine tumor (PET) is an uncommon neoplasm of the pancreas with distinct cytomorphologic features. Lipid-rich PET, a rare variant, histologically deviates from that of a conventional PET. There is only one case report of the cytologic features of this rare entity in the literature. We report two cases of lipid-rich PETs diagnosed by endoscopic ultrasound-guided FNA biopsy. Case 1 showed large aggregates, small clusters, and single cells with plasmacytoid appearance, small uniform nuclei, coarse chromatin, and prominent nucleoli. Abundant distinct small cytoplasmic vacuoles were present in almost all tumor cells and the background was clean. Case 2 showed flat cohesive sheets of medium-sized uniform cells with indistinct plasmacytoid appearance, uniform nuclei, fine and evenly distributed chromatin, and inconspicuous nucleoli. Distinct small cytoplasmic vacuoles were seen only focally. Immunohistochemical stains in cell blocks of both cases confirmed the diagnosis of PET. Lipid-rich PET may be misinterpreted on cytology specimens if the pathologist is not aware of this rare entity since it mimics clear cell carcinoma of the kidney, adrenal cortical neoplasm, or adenocarcinoma of the pancreas.

Performance of endoscopic ultrasound-guided fine needle aspiration in diagnosing pancreatic neuroendocrine tumors

Background:

Pancreatic neuroendocrine tumors (PNETs) are rare tumors of the pancreas, which are increasingly diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). In this retrospective study, we assessed the performance of EUS-FNA in diagnosing PNETs.

Materials and Methods:

We identified 48 cases of surgically resected PNETs in which pre-operative EUS-FNA was performed. The clinical features, cytological diagnoses, and surgical follow-up were retrospectively reviewed. The diagnostic performance of EUS-FNA was analyzed as compared to the diagnosis in the follow-up. The cases with discrepancies between cytological diagnosis and surgical follow-up were analyzed and diagnostic pitfalls in discrepant cases were discussed.

Results:

The patients were 20 male and 28 female with ages ranging from 15 years to 81 years (mean 57 years). The tumors were solid and cystic in 41 and 7 cases, respectively, with sizes ranging from 0.5 cm to 11 cm (mean 2.7 cm). Based on cytomorphologic features and adjunct immunocytochemistry results, when performed, 38 patients (79%) were diagnosed with PNET, while a diagnosis of suspicious for PNET or a diagnosis of neoplasm with differential diagnosis including PNET was rendered in the 3 patients (6%). One case was diagnosed as mucinous cystic neoplasm (2%). The remaining 6 patients (13%) had non-diagnostic, negative or atypical diagnosis.

Conclusions:

Our data demonstrated that EUS-FNA has a relatively high sensitivity for diagnosing PNETs. Lack of additional materials for immunocytochemical studies could lead to a less definite diagnosis. Non-diagnostic or false negative FNA diagnosis can be seen in a limited number of cases, especially in those small sized tumors.

Cytology of the Pancreas: A Practical Review for Cytopathologists

Pancreatic cytopathology plays a critical role in the management of patients with cystic and solid pancreatic masses. The frequency of pancreatic fine-needle aspiration continues to increase and general surgical pathologists and cytopathologists need to be aware of the most commonly encountered entities as well as the pitfalls associated with gastrointestinal tract contaminants in endoscopic ultrasound-guided fine-needle aspiration. This article focuses on the most commonly encountered pancreatic lesions and the importance of correlation of cytologic features with clinical, radiologic, and ancillary studies for accurate diagnosis.

FNAC diagnosis of pancreatic somatostatinoma

Somatostatinomas are rare pancreatic endocrine neoplasms (PEN). We present a case of a PEN in a 63-year-old lady having diabetes mellitus, cholelithiasis, steatorrhea, weight loss, indigestion, nausea and fatigue. Ultrasonography revealed a large calcified mass occupying the liver, pancreas and emboli in the splenic vein. Fine needle aspiration cytology (FNAC) of the metastatic mass in the liver showed features of neuroendocrine tumor. Correlating the clinical picture, computed tomography and cytological findings, a diagnosis of pancreatic somatostatinoma was suggested. Serum somatostatin levels and biopsy findings confirmed the same. The patient was put on chemotherapeutic agents and octreotide and is doing well after two years of follow-up. We discuss the FNAC findings of pancreatic endocrine tumors and its differentiating features from hepatoma and other small round cell tumors.

Cystic pancreatic endocrine tumors: an endoscopic ultrasound-guided fine-needle aspiration biopsy study with histologic correlation

BACKGROUND

Cystic pancreatic endocrine tumors (PETs) are rare neoplasms with a preoperative diagnostic challenge. The aim of this study was to evaluate the preoperative diagnostic strategy for these tumors and to assess the clinical and pathologic characteristics.

METHODS

Six cases of cystic PET were retrospectively enrolled. Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) was performed in 4 cases. All cytomorphologic data from conventional smears, ThinPrep preparations, and cell block preparations were reported in detail.

RESULTS

There were 3 male and 3 female patients with a mean age of 52.3 years. Tumor size ranged from 10 mm to 60 mm (mean, 29.8 mm). EUS-FNAB contributed to an accurate diagnosis in all cases. Cytologically, loosely cohesive aggregates and single cells were predominant. Cells were small and typically plasmacytoid, with occasional cytoplasmic vacuolization. Nuclei were round or oval, uniform, with finely and evenly distributed chromatin. Immunocytochemistry confirmed the endocrine differentiation. Histologic findings were typical for endocrine proliferation. All tumors were well differentiated.

CONCLUSIONS

Cystic PET is an unusual finding that presents diagnostic challenges for both endoscopists and cytologists. EUS-FNAB with the Thinprep preparation technique and cell block material were found to be helpful in improving diagnostic accuracy. Immunocytochemical staining with endocrine markers confirmed the diagnosis.

Proliferative rate in endoscopic ultrasound fine-needle aspiration of pancreatic endocrine tumors: correlation with clinical behavior

BACKGROUND

The objectives of this study were to evaluate the role of endoscopic ultrasonography (EUS)-guided fine-needle aspiration (FNA) in the preoperative diagnosis of pancreatic endocrine tumors (PETs) and to investigate whether the Ki-67 index determined on cytologic material could help predict their behavior.

METHODS

The study included 10 men and 5 women (ratio of men to women, 2:1) with a mean age of 62.4 years (range, 40-79 years). Diff-Quik- and Papanicolaou-stained FNA samples were analyzed retrospectively, and immunocytochemical stains were performed for chromogranin A, synaptophysin, vimentin, alpha-1-antitrypsin, and Ki-67 on cell block sections. The Ki-67 index was evaluated by using digital image-analysis software and was correlated with follow-up (mean, 21.5 months; range, 2-43 months).

RESULTS

The overall survival was rate 86.7% (13 of 15 patients). Seven of 15 patients (46.7%) patients developed lymph node and/or hematogenous metastases. The Ki-67 index in PETs with no metastases was lower (mean, 6.3%; range, 2%-13%) than in clinically aggressive (metastatic) tumors (mean, 7.7%; range, 3%-27%; P = .03). None of the tumors that had a Ki-67 index < or =2% were metastatic. Both patients who died of disease had a Ki-67 index of 4%.

CONCLUSIONS

Although tumors with metastatic potential tended to exhibit a slightly higher Ki-67 index, there was a significant overlap with nonmetastatic tumors, and PETs that had a very low proliferative rate still could behave aggressively; therefore, the authors concluded that the Ki-67 index does not predict the risk of disease progression in patients with PETs.

Pancreatic cytopathology: a practical approach and review

CONTEXT

Pancreatic cytopathology plays an important role in the diagnosis and management of patients with solid and cystic lesions of the pancreas.

OBJECTIVE

To serve as a practical guide to pancreatic cytopathology for the practicing pathologist. Data Sources.-A comprehensive assessment of the medical literature was performed.

CONCLUSIONS

We review pancreatic cytopathology, with specific discussions of its role in patient management, specimen types and specimen processing, specific diagnostic criteria, and the use of ancillary testing and advanced techniques.

Endoscopic ultrasound-guided fine-needle aspiration cytology of pancreatic neuroendocrine tumors: a study of 48 cases

BACKGROUND

Neuroendocrine tumors (NETs) of the pancreas are relatively uncommon tumors. The objective of this report was to describe the cytopathologic and immunocytochemical features of NETs obtained by endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA).

METHODS

Forty-eight patients who were diagnosed with pancreatic NETs based on EUS-guided FNA were studied retrospectively (from 2002 to 2007). Clinical data, EUS findings, cytopathologic features, and immunocytochemical stains were reviewed for this study. The final histopathologic diagnosis from each patient also was available for comparison.

RESULTS

Forty-eight patients (28 men and 20 women) who ranged in age from 16 years to 86 years were selected and had the following clinical findings: solid or multiple pancreatic masses diagnosed by computed tomography or magnetic resonance imaging studies; simultaneous, suspicious, metastatic masses in the liver, mediastinum, and/or lung; hypoglycemia; multiple endocrine neoplasia type 1 syndrome; von Hippel-Lindau syndrome; and primary NET of the small bowel. EUS findings revealed solid or multiple masses in the pancreatic head/uncinate, or in the pancreatic body/tail, or simultaneously in the pancreatic head/uncinate and body/tail. Cytologically, 40 patients were diagnosed with NETs (histopathogically confirmed), and 8 patients had findings that were suspicious of NETs (2 patients had false-positive results, and 6 patients had histopathologically confirmed NETs). The most helpful cytologic findings for the diagnosis of NET were a richly cellular sample with a monotonous, poorly cohesive population of small or medium-sized cells with granular chromatin (salt and pepper) and plasmacytoid morphology. Immunocytochemistry confirmed the neuroendocrine origin of tumors in 40 patients (material for immunocytochemistry was inadequate in 8 patients).

CONCLUSIONS

The current results indicated that EUS-guided FNA is a useful method for the diagnosis of pancreatic NETs. Cytopathologic examination in coordination with immunocytochemistry can provide an accurate diagnosis in most patients.

Endoscopic ultrasound-guided fine needle aspiration cytology of the pancreas: a morphological and multimodal approach to the diagnosis of solid and cystic mass lesions

Cytological evaluation of pancreatic masses and cysts is the preferred pre-operative diagnostic modality and is increasingly being performed by endoscopic ultrasound. This review focuses on the multimodal approach at the Massachusetts General Hospital that utilizes clinical, cytological, radiological and ancillary studies in rendering a final cytological diagnosis.

Cystic pancreatic endocrine tumor

BACKGROUND

Most cystic pancreatic neoplasms are currently evaluated by an endoscopic ultrasound-guided fine-needle aspiration biopsy (FNAB). In the authors' experience, FNAB of cystic pancreatic endocrine tumors (PETs) frequently causes diagnostic difficulties, partly because of unexpected overlapping features with cystic ductal adenocarcinomas.

METHODS

The authors identified 5 histologically confirmed cystic PETs that were evaluated by FNAB and compared their cytomorphologic features to cystic ductal adenocarcinomas (n = 5) and solid PETs (n = 39) of the pancreas.

RESULTS

Cytologically, 2 of the aspirates of cystic PETs were devoid of tumor cells whereas the other 3 were variably cellular and composed of cohesive aggregates of monomorphic cellular elements with variably coarse chromatin. Tumor necrosis and nuclear membrane irregularities were not identified in cystic PETs. Alternatively, in contrast to PETs, cystic ductal adenocarcinomas were characterized by nuclear pleomorphism, nuclear membrane irregularities, and tumor necrosis.

CONCLUSIONS

Given the clinical implications, awareness of cystic PETs and their deceptive cytologic features would assist in distinguishing these lesions from cystic ductal adenocarcinomas.

Endoscopic ultrasound-guided fine needle aspirate microsatellite loss analysis and pancreatic endocrine tumor outcome

BACKGROUND & AIMS

The clinical course of pancreatic endocrine tumor (PET) varies depending on tumor aggressiveness, disease extent, and possibly accumulated molecular alterations. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) results, although accurate in diagnosing PET, correlate poorly with PET outcome. The role of detecting key molecular abnormalities in predicting PET behavior and clinical outcome from EUS-FNA material remains unknown.

METHODS

Patients with confirmed PET who underwent EUS-FNA during a 32-month period were included. Patient demographics and clinical data were recorded and follow-up information was obtained by contacting their physician to evaluate disease progression. Representative tumor cells were microdissected from the FNA material. DNA was harvested and amplified, targeting a panel of 17 polymorphic microsatellite markers on chromosomes 1p, 3p, 5q, 9p, 10q, 11q, 17p, 17q, 21q, and 22q. The polymerase chain reaction products were subjected to fluorescent capillary gel electrophoresis to detect microsatellite loss. The fractional allelic loss (FAL) was calculated.

RESULTS

Twenty-five patients were studied. Thirteen were classified histologically as benign PET limited to the pancreas and 12 as malignant PET (invasive or metastatic). The mean FAL in the benign and malignant PET was 0.03 and 0.37 (P<.0001), respectively. In addition, the mean FAL was significantly greater in those with disease progression as compared with patients with stable disease (0.45 vs 0.09 respectively, P<.0001).

CONCLUSIONS

Microsatellite loss analysis of EUS-FNA material from PET can be performed reliably and an FAL value of more than 0.2 is associated with disease progression. This technique may have value in the preoperative assessment and risk stratification of patients with PET.

The diagnosis of malignancy in effusion cytology: a pattern recognition approach

This review presents a pattern recognition approach for the diagnosis of malignant effusions. The cytomorphologic features of reactive mesothelial proliferation, mesothelioma and metastatic carcinoma are presented. In addition, the role of ancillary studies in challenging cases and the importance of integrating clinical findings are stressed. An algorithmic approach to the workup of serous effusions as well as pitfalls for false-positive diagnosis are discussed.

Review of endoscopic ultrasound-guided fine-needle aspiration cytology

This review, based on the Hennepin County Medical Center experience and review of the literature, vastly covers the up-to-date role of endoscopic ultrasonography (EUS) and EUS-guided fine-needle aspiration (FNA) in evaluating tumorous lesions of the gastrointestinal tract and adjacent organs. Emphasis is given to the tumoral and nodal staging of esophageal, pulmonary, and pancreatic cancer. This review also discusses technical, pathological, and gastroenterologic aspects and the role of the pathologist and endosonographer in the evaluation of these lesions, as well as the corresponding FNA cytology and differential diagnosis.

Endoscopic ultrasound-guided fine needle aspiration cytology of pancreatic neuroendocrine tumours: cytomorphological and immunocytochemical evaluation

OBJECTIVES

Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) is increasingly used in preoperative localization and diagnosis of pancreatic neoplasms including neuroendocrine tumours (NETs). The objective of the present study was to identify the cytological features of pancreatic NETs obtained by EUS-FNA.

METHODS

The study group consisted of nine cases of pancreatic tumours correctly diagnosed or strongly suggestive of NETs based on EUS-FNA. Cytological smears were retrospectively reviewed. The clinical data and immunocytochemical stains applied to the cell block preparations were also reviewed and examined.

RESULTS

All cases except one showed characteristic cytomorphological features sufficient for their recognition and separation from pancreatic adenocarcinoma and other lesions. The most helpful cytological features that facilitated the cytological diagnosis of NET were a richly cellular aspirate with a monotonous, poorly cohesive population of small cells with a speckled or dusty chromatin pattern and plasmacytoid morphology. The neuroendocrine differentiation of these tumours was further confirmed by immunocytochemistry.

CONCLUSION

EUS-FNA is a valuable method in the recognition of pancreatic NETs. By adherence to the characteristic cytomorphological criteria of pancreatic NET together with collection of suitable material for ancillary immunocytochemical stains, cytopathologists could reach a correct diagnosis in most instances.

Cytologic diagnosis of pancreatic endocrine tumors by endoscopic ultrasound-guided fine-needle aspiration: A review

Precise localization and diagnosis of pancreatic endocrine tumors (PETs) is important, because pancreatic PETs have different clinical and biological behavior and treatment modalities than do exocrine pancreatic tumors. In contrast to the much more common exocrine adenocarcinomas, cytologic studies of PET are relatively rare and many cytopathologists lack experience with the cytomorphologic features of these tumors.During the last 10 yr, endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) has matured into an accurate, highly sensitive, and cost-effective modality for the preoperative localization of pancreatic PETs. This has resulted in an increased number of PETs first sampled as cytology specimens. This manuscript focuses on the cytomorphologic features most suggestive of pancreatic PETs, differential diagnosis, and diagnostic pitfalls of PETs. The technical development of EUS-guided FNA and the ancillary studies for pancreatic PETs are also reviewed. The data summarized in this review indicate that EUS-FNA is a valuable method in the recognition of pancreatic PETs and in most cases cytopathologists could reach a correct diagnosis of these tumors, including their hormone producing capability on aspirated cytologic material.

Fine-needle aspiration cytology of pancreatoblastoma in a young woman: report of a case and review of the literature

Pancreatoblastoma is a rare tumor and has been reported only four times in the cytologic literature, three times in fine-needle aspiration (FNA) biopsy and once in an imprint of resected tumor. We are reporting the fourth case of FNA cytology with immunohistochemical and electron microscopic studies. The patient is a 24-yr-old African American woman, who presented with a pancreatic mass, hepatic masses, and abdominal lymphadenopathy. The aspiration smears of the liver mass showed a biphasic tumor composed of bland-appearing primitive spindled stromal fragments with "spider-web"-like long fibrils interconnecting with sharply angulated islands of cohesive epithelium. At high power, the epithelium is composed of medium-sized cells with round-to-oval vesicular nuclei with fine chromatin and one-to-two small nucleoli. The neuroendocrine component was demonstrated immunohistochemically with synaptophysin and chromogranin expressions. The acinar component and squamoid component were demonstrated ultrastructurally by the presence of 400-600 nm zymogen granules and tonofilaments. The literature was reviewed and the cytological features of all the four cases of pancreatoblastoma are summarized.