Pancreatic Tumors. Группа авторов

the clinical, imaging, cytological, and ancillary test findings. This volume provides the reader with the information necessary to assess a cytological specimen of the pancreas using a multidisciplinary approach. It describes and illustrates the cytological criteria of the most common non-neoplastic, neoplastic, and cystic lesions of the pancreas, and includes the pertinent clinical, imaging, and ancillary testing. A solid understanding of the histopathology of pancreatic lesions is also required to better evaluate pancreatic cytology. The histological features are included, and an approach to the differential diagnoses and potential pitfalls is reviewed.

      This book provides a comprehensive review of entities that may be encountered in pancreatic cytology. It is designed for cytotechnologists, pathology trainees, pathologists, and cytopathologists. It is also a useful guide for advanced endoscopists performing EUS-guided FNA, and surgeons and oncologists treating patients with pancreatic disease wanting to understand their pathology reports.

      The work presented here is the product of years of experience and curiosity of the senior editor, Dr. Centeno, who has witnessed the evolving landscape of pancreatic cytology, since the inception of EUS-guided FNA and pancreatic cyst fluid cytology. Dr. Centeno is honored to share her experience with the reader and to educate and mentor, with her colleague, Dr. Dhillon, the next generation of cytopathologists.

      Barbara A. Centeno, Tampa, FL

      Jasreman Dhillon, Tampa, FL

       Chapter 1

      Published online: September 29, 2020

      Centeno BA, Dhillon J (eds): Pancreatic Tumors. Monogr Clin Cytol. Basel, Karger, 2020, vol 26, pp 1–14 (DOI:10.1159/000455729)

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       Introduction to Pancreatic Pathology and Fine-Needle Aspiration Cytology

      Jasreman Dhillon^{a, b}

      ^aDepartment of Anatomic Pathology, Moffitt Cancer Center, Tampa, Florida, USA; ^bDepartment of Oncologic Sciences and Pathology, University of South Florida, Tampa, Florida, USA

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      Abstract

      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.

      © 2020 S. Karger AG, Basel

      Demographics of Pancreatic Tumors

Primary malignant epithelial neoplasms of the pancreas are currently classified based on their phenotype into ductal, acinar, or neuroendocrine. Some remain unclassified as to their phenotype. Pancreatic ductal adenocarcinoma (PDAC) is the most common type, accounting for approximately 90% of the tumors [1].

Pancreatic cancer is the seventh leading cause of cancer deaths in the industrialized world and third most common in the USA [2]. Based on GLOBOCAN 18 estimates, it ranks as the eleventh most common cancer in the world, accounting for 4.5% of all deaths caused by cancer [2]. The highest mortality rates are in Western Europe (7.6 per 100,000 people), Central and Eastern Europe (7.3), and Northern Europe and North America equally (6.5). The lowest are in Eastern Africa (1.4) and South Eastern Asia and West Africa (2.1). Pancreatic cancer is trending to increase from 2018 to 2040 worldwide (+77.7% new cases and +79.9% deaths) [2].

      The average lifetime risk of pancreatic cancer for both men and women is about 1 in 64 (1.6%). According to the American Cancer Society, about 57,600 people (30,400 men and 27,200 women) will be diagnosed with pancreatic cancer in the year 2020 and about 47,050 people will die of pancreatic cancer in the USA (www.cancer.org).

Table 1. Syndromes and their associated gene mutations

The incidence increases with age for both sexes [2]. Pancreatic cancer is usually present in patients older than 65 years of age, with a median age at diagnosis of 71 years. There is a slight preponderance in men. Risk factors associated with pancreatic cancer include older age, smoking, obesity, and exposure to certain chemicals used in dry cleaning and metal industries. Smoking is a firmly established risk factor for pancreatic cancer [3]. Compared to those who have never smoked, the overall risk is 1.40 for ever cigarette smokers, 1.17 for former cigarette smokers, and 2.2 for current cigarette smokers [3]. The risk of PDAC decreases with smoking cessation. Another potentially modifiable factor implicated in the development of pancreas cancer is a high body mass index (BMI). Insulin resistance is hypothesized as a mechanism contributing to this increase in risk in patients with a high BMI [4].

A family history of pancreatic cancer, usually defined as having at least one affected first degree relative, is seen in 5–10% of individuals with this disease [5, 6]. Risk is known to increase strongly in families with several members affected [7]. Familial pancreatic cancer characterizes families with an abnormally high rate of pancreatic cancer in which an inherited gene is suspected but has not been identified. Individuals with familial pancreatic cancer may have a specific genetic mutation that is linked to a syndrome which predisposes them to certain types of cancer. Mutations in a number of genes are related to increased risk of PDAC. Currently, at least twelve inherited gene mutations are known to increase the predisposition to pancreatic cancer [8]. The genetic syndromes included are hereditary breast and ovarian cancer syndrome, familial atypical multiple mole melanoma syndrome, familial pancreatitis, Lynch syndrome, and Peutz-Jeghers syndrome. PALB2 and ATM have recently been associated with familial cancers [8]. The inherited syndromes and gene mutations associated with pancreatic cancer are shown in Table 1a.

Other neoplasms and malignancies are less common. Pancreatic neuroendocrine tumors (PanNETs) comprise approximately 5% of pancreatic malignant tumors [1]