Ebook Atlas of non-gynecologic cytology: Part 2

Continued part 1, part 2 of ebook Atlas of non-gynecologic cytology provide readers with content about: pancreaticobiliary tract cytology; liver cytology; kidney and adrenal gland cytology; urine cytology; serous effusion cytology; lymph node cytology;... Please refer to the ebook for details!

6 Pancreaticobiliary Tract Cytology Judy Pang and Andrew Sciallis Introduction The major indications for cytologic evaluation of the pancreaticobiliary tract are a pancreatic mass and/or a bile duct stricture Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the primary modality for obtaining tissue diagnosis; it has largely replaced percutaneous FNA because it allows for real-time visualization of the needle, provides better visualization of small lesions than CT guidance, and enables the sampling of regional lymph nodes and assessment of invasion of local structures, thus providing simultaneous diagnosis and staging [1–3] The sensitivity of EUS-FNA for solid masses has been reported to range from 54 to 95%, with specificity approaching 100% [4] The role of EUS-FNA is less clear for cystic lesions, as the sensitivity is generally lower and more variable in detecting a neoplastic mucinous cyst than a solid neoplasm, ranging from 23 to 100% [5] Furthermore, the sensitivity of detecting a malignancy in a neoplastic mucinous cyst is reported to be 29%, with 100% specificity [6, 7] Endoscopic retrograde cholangiopancreatography (ERCP) with bile duct brushings for cytology is an additional minimally invasive modality to obtain material for tissue diagnosis, which can be helpful in the assessment of pancreatic neoplasms, particularly ductal adenocarcinomas The sensitivity of brushings is reported to be lower than that of EUS-FNA, 44–72% [8–11], but the specificity approaches 100%, similar to EUS-FNA The Papanicolaou Society of Cytopathology has proposed a terminology scheme for the reporting of pancreaticobiliary cytology, utilizing a six-tiered system, as shown on Table 6.1 [12] Sampling of pancreatic head masses is performed using a transduodenal approach, whereas a transgastric approach is used for the body and tail masses It is important for the pathologist to be aware of the approach so that contaminating normal duodenal mucosa (Fig. 6.1) and gastric mucosa (Fig. 6.2) is not misinterpreted as lesional tissue Table 6.1  Papanicolaou society of cytopathology system for reporting pancreaticobiliary cytology I Nondiagnostic II Negative (for malignancy) III Atypical IV Neoplastic   • Benign    – Serous cystadenoma    – Neuroendocrine microadenoma    – Lymphangioma   • Others     –  Well-differentiated neuroendocrine tumor    – Solid pseudopapillary tumor     – Intraductal papillary mucinous neoplasm, all grades of dysplasia     –  Mucinous cystic neoplasm, all grades of dysplasia V Suspicious (for malignancy) VI Positive or malignant  •  Pancreatic ductal adenocarcinoma   • Cholangiocarcinoma  •  Acinar cell carcinoma  • Poorly differentiated (small-cell and large-cell) neuroendocrine carcinoma   • Pancreatoblastoma   • Lymphoma   • Metastatic malignancy Adapted from Pitman [12] J Pang, M.D (*) · A Sciallis, M.D Department of Pathology, The University of Michigan, Ann Arbor, MI, USA e-mail: jcpang@med.umich.edu; sciallis@med.umich.edu © Springer International Publishing AG, part of Springer Nature 2018 X Jing et al (eds.), Atlas of Non-Gynecologic Cytology, Atlas of Anatomic Pathology, https://doi.org/10.1007/978-3-319-89674-8_6 157 158 a J Pang and A Sciallis b Fig 6.1  Duodenal epithelium is often seen in aspirates of masses from the pancreatic head or proximal body Typically seen are flat sheets of epithelial cells with uniform small nuclei studded with occasional goblet cells (a) Diff-Quik stain; (b) Papanicolaou stain Fig 6.2  Gastric epithelium is often seen in aspirates of masses from the pancreatic distal body or tail It typically appears as flat sheets of mucinous epithelial cells with uniform small nuclei In this image, adjacent to the gastric epithelium is a small cluster of disordered malignant cells (Papanicolaou stain) Fig 6.3  Benign pancreatic ductal epithelial cells have uniform small round nuclei and are arranged in cohesive, evenly spaced honeycomb sheets (Diff-Quik stain) Normal Pancreas Figures 6.3, 6.4, and 6.5 show examples of normal pancreatic elements Fig 6.4  Benign acinar cells are reminiscent of “grapelike” clusters when associated with fibrovascular tissue (Papanicolaou stain) 6  Pancreaticobiliary Tract Cytology 159 a Fig 6.5  Benign acinar cells are polygonal with abundant granular cytoplasm (Papanicolaou stain) b Solid Pancreatic Masses EUS-FNA of solid pancreatic masses is not always necessary when a solid mass detected on imaging is considered to be resectable, as a benign cytology does not entirely exclude a malignancy It is most useful in patients who have unresectable disease or are poor surgical candidates, in whom tissue diagnosis is necessary prior to the initiation of chemotherapy or radiation [13] It is also helpful when it is not clear from clinical and radiologic findings whether a mass is attributable to a benign process such as pancreatitis (Figs. 6.7, 6.8, and 6.9), when the patient has a prior history of another malignancy, or when a lymphoma is suspected In these scenarios, surgical resection may not be indicated Fig 6.6  Stromal fragments in chronic pancreatitis (a) Diff-Quik stain; (b) Papanicolaou stain Pancreatitis Figures 6.6 and 6.7 show features of pancreatitis Pancreatic Ductal Adenocarcinoma Pancreatic ductal adenocarcinoma can be identified from a number of characteristics of its cytomorphology, as illustrated in Figs. 6.8, 6.9, 6.10, 6.11, 6.12, and 6.13: • Disordered, crowded epithelial sheets (“drunken honeycomb”) • Single malignant cells • Irregular nuclear contours (grooves, convolutions) • Irregular chromatin (clearing and clumping) • Nuclear enlargement • Prominent nucleoli • Nuclear pleomorphism (4:1 nuclear diameter size difference within a single cluster/sheet) • Prominent mucinous vacuolization Fig 6.7  Pancreatitis Cohesive cluster of slightly crowded ductal cells with slightly enlarged round to oval nuclei, smooth nuclear membranes, and small nucleoli There is little variation in nuclear diameter within the same sheet (