Monographs in clinical cytology最新文献

This introductory chapter discusses the demographics of pancreatic tumors and the risk factors associated with pancreatic neoplasms. The WHO 2019 classification of pancreatic epithelial tumors and WHO 2017 classification of pancreatic neuroendocrine neoplasms is provided. The current role of fine-needle aspiration (FNA) in the pancreatic lesions, different radiographic modalities and their evolution in the FNA of pancreatic lesions, and utility of rapid on-site evaluation of pancreatic cytology is also discussed. Guidelines on pancreatic pathology provided by the Papanicolaou Society of Cytopathology (PSC) in 2014 are summarized. These guidelines, which are provided by experts in the field, establish recommendations for clinical follow-up, indications, and preprocedural studies for pancreatic FNA, different techniques of pancreatic FNA, postprocedural follow-up, treatment options for different pancreatobiliary lesions, and utilization of ancillary studies for cytological diagnosis of pancreatic lesions. Standardization of the terminology and nomenclature and the diagnostic categories provided by the PSC are also discussed. Lastly, an algorithmic approach to cytological evaluation of pancreatic masses is provided.

The pancreas is a retroperitoneal organ located in the duodenal loop with the posterior wall of the stomach overlying it and the left lobe of the liver lying anteriorly to it. Tissues from these organs, in addition to the lesion of interest within the pancreas, may be sampled during fine-needle aspiration (FNA) procedures. Therefore, it is important to recognize the cytology of normal benign components of the pancreas and potential contaminants in order to render a correct diagnosis and avoid pitfalls. Normal components of the pancreas include ductal epithelial cells, acinar cells, and islet cells. In addition to the normal pancreatic cells, it is not uncommon to encounter epithelial cells from the duodenal and gastric mucosa with endoscopic ultrasound-guided fine-needle aspiration. It is important to recognize these cells as benign and to distinguish them from a well-differentiated pancreatic adenocarcinoma. Besides these, mesothelial cells and hepatocytes and bile duct cells from the liver may be sampled as well. Here, the cytological features of normal components and contaminants are described in detail.

Benign non-neoplastic solid lesions of the pancreas are comprised of several separate entities, with their diagnostic identification best performed in correlation with the radiographic and clinical features. These include all of the pancreatitides, intrapancreatic spleen, and a few other rare entities. Preoperative imaging may suggest the correct diagnosis, but occasionally the preoperative imaging findings may be misleading because they overlap with those of pancreatic neoplasms. Masses associated with typical pancreatitides are rarely sampled due to their distinct clinical picture and relative frequency; however, the uncommon variants of pancreatitis may also present as mass lesions mimicking malignancy. Herein, we will discuss the cytopathologic findings of several solid pancreatic lesions, including acute pancreatitis, chronic pancreatitis, autoimmune pancreatitis, paraduodenal or groove pancreatitis, and other mass lesions, such as intrapancreatic accessory spleen and abscess. The key cytological features, ancillary studies, and differential diagnoses will also be discussed.

This chapter describes the mesenchymal tumors of the pancreas which are of rare occurrence. Mesenchymal tumors of the pancreas may be benign, of intermediate biological potential or malignant. The more commonly occurring mesenchymal tumors of the pancreas are described in this chapter along with their appropriate immunohistochemical workup and differential diagnoses.

It is important to adequately process and triage the specimen obtained from fine-needle aspirations (FNAs) of pancreatic lesions. Many echo endoscopists rely on rapid on-site evaluation (ROSE) for adequacy of FNA from solid pancreatic lesions. The role of ROSE in FNA of pancreatic lesions is discussed, as is the triage of material for making smears and cell block preparation. Different techniques of cell block preparation are briefly mentioned. Pancreatic cystic fluid obtained from pancreatic cysts is triaged differently as compared to specimens obtained from solid pancreatic lesions. An algorithmic approach to the processing of pancreatic cystic fluid for molecular and biochemical assays and cytology is discussed. Proper specimen handling is crucial to the accurate interpretation of pancreatic FNA specimens. The methods used to process a sample depend on whether the aspirated sample is solid or cystic and the type of device used for sampling. ROSE has been shown to reduce the number of inadequate specimens and to improve specimen preparation. The details of the various cytological preparation methods available are described in numerous texts. Here we focus on providing a broad overview of specimen collection and processing as it relates to pancreatic FNA, with guidance to the reader based on published and personal experiences.

Imaging plays a key role in the diagnosis and staging of pancreatic tumors. Imaging modalities utilized for the evaluation of pancreatic tumors include: transabdominal and endoscopic ultrasound, computed tomography, and magnetic resonance imaging. Each of these modalities has different strengths and weaknesses which must be considered in the setting of evaluating a pancreatic tumor. Imaging can determine if a pancreatic tumor is cystic or solid and help develop a differential diagnosis based on the lesion's imaging features. If a malignant pancreatic tumor is diagnosed, imaging can assist with initial staging by determining the size and local extent of the tumor as well as evaluating for nodal and metastatic disease. Here we review the different imaging modalities utilized to evaluate pancreatic masses, describe the key imaging features of the most significant entities in the differential diagnosis, and describe the diagnostic imaging approach.

The pancreas is infrequently the site of secondary involvement by solid or hematopoietic malignancies. While carcinomas and melanoma are the most common malignancies to secondarily involve the pancreas, the literature is replete with reports of uncommon and rare entities metastasizing to the pancreas. Fine-needle aspiration is indicated to establish the diagnosis and direct patient management. Diagnostic accuracy depends on correlation with clinical and imaging findings, previous pathology if known, and selection of the appropriate ancillary studies. Here we review the cytopathology of secondary tumors involving the pancreas and provide an approach to the diagnostic work-up.

Inflammatory, developmental, and neoplastic lesions may all present as cystic masses on imaging. Pseudocyst is the most common of these and presents in association with a history of pancreatitis. Pancreatic cystic neoplasms are uncommon compared to solid neoplasms. They often present incidentally; therefore, an incidentally discovered cyst in the pancreas should be assessed with a high index of suspicion for neoplasm. The most common and frequently encountered cystic neoplasms include serous cystadenoma, mucinous cystic neoplasm, and intraductal papillary mucinous neoplasm. Less common epithelial cystic neoplasms include acinar cell cystadenoma and cystadenocarcinoma. Any solid neoplasm occurring in the pancreas or vicinity of the pancreas that has undergone cystic degeneration may present as a cystic mass. Non-epithelial lesions, such as lymphangioma, are also included in the differential diagnosis. The work-up needs to begin with a review of the clinical and imaging findings to establish a differential diagnosis. The primary focus of the pathologist will be first on differentiating mucinous from non-mucinous entities, since this will determine if the mass is an intraductal papillary mucinous neoplasm or a mucinous cystic neoplasm. If it is mucinous, the next step is to determine if the cystic neoplasm contains cells with high-grade cytological features. If it is non-mucinous, the pathologist needs to assess for neoplastic cells that would indicate a different neoplastic process. The cytological features need to be integrated with cyst fluid carcinoembryonic antigen and amylase measurements. Currently, molecular pathology is being integrated into the analysis of pancreatic cyst fluids. Here we will cover the cytological features and ancillary findings in cystic masses of the pancreas.