Anatomy and histology of the pancreas
Ductal adenocarcinoma
Ductal adenocarcinoma It is the most common pancreatic tumor (85-90%). It usually occurs in elderly patients and most commonly involve the head of the pancreas. It has been associated with smoking and recurrent pancreatitis and its prognosis is poor. Cytologic diagnostic features (moderately to poorly differentiated tumors) Increased cellularity Crowded sheets (with feathered edges) Single […]
Reporting terminology
Reporting terminology Diagnostic terminology for pancreatic FNA used empirically a five-tier system including the following categories: Negative for malignant cells Atypical cells present Suspicious cells present Positive for malignant cells Non-diagnostic specimen A negative diagnosis in the setting of a radiologically detected mass implies either a failure to sample the lesion or the presence of […]
Metastatic tumors
Metastatic tumors FNA is particularly useful in documenting a metastatic malignancy involving the pancreas. Lung carcinoma (small cell and squamous cell) Breast carcinoma Non-Hodgkin lymphoma Renal cell carcinoma Because ductal cell adenocarcinoma is by far the most common pancreatic tumor, any aspirate showing cytologic features unusual for this diagnosis should raise the possibility of a […]
Fine needle aspiration (FNA) and other sampling methods
Fine needle aspiration (FNA) Fine needle aspiration (FNA) is the sampling method of choice for evaluating pancreatic masses. It is a procedure with few complications which can confirm malignancy in a minimally invasive manner. It is effective in the diagnosis of tumors, but cystic pancreatic lesions and non-neoplastic processes may also be evaluated by FNA. […]
Pancreatic endocrine tumors
Pancreatic endocrine tumors They were previously referred to as islet cell tumors, but the term pancreatic endocrine tumors (PET) is more appropriate since they arise from multipotent ductular stem cells in addition to isles of Langerhans. They account for 1-2% of pancreatic tumors. They are located most commonly in the body and the tail and […]
Biliary tract cytology
Biliary tract cytology Sampling methods Cytologic specimens from biliary tract include brushings, exfoliated bile, and rinse specimens from biliary stents.Brushing specimens may be obtained either by endoscopic retrograde cholangiopancreatography or by percutaneous transhepatic cholangiography, the former being more sensitive than the latter. Rinse specimens may be obtained from a a biliary stent at the time […]
Solid-pseudopapillary tumor
Solid-pseudopapillary tumor This rare tumor usually occurs in women in their second or third decades of life. It presents as a large abdominal mass and has low malignant potential, although rare cases of metastatic disease have been reported. Histologically, it is characterized by fine fibrovascular septa forming the core of pseudopapillary structures, which result from […]
Normal cells
Normal cells Fine needle aspiration of normal pancreas yield a combination of benign acinar and ductal epithelial cells. Benign acinar epithelium cytologic features Single cells or acini Eccentrically placed, round nuclei Evenly distributed, finely granular chromatin Incospicuous nucleoli Abundant granular cytoplasm Indistinct cell borders Benign ductal epithelium cytologic features Flat, cohesive honeycomb sheets […]
Pancreatic cysts
Pancreatic cysts The evaluation of pancreatic cysts requires a multidisciplinary approach. No single diagnostic test provides 100% sensitivity and specificity. The absence of cyst lining cells implies a pseudocyst in the appropriate clinical setting, but this is a diagnosis of exclusion. In the case of cysts the fluid is separately submitted for carcinoembryonic antigen (CEA), amylase, […]