Cytology of head and neck tumors, liver, and pancreas

The use of fine needle aspiration biopsy helps in reducing the number of thyroidectomies. Cytologic differentiation between cellular adenomas and well-differentiated follicular carcinomas is difficult, however; hence, both groups of lesions should be excised. Cytologic diagnosis of the common salivary gland tumors (ie, pleomorphic adenomas and Warthin's tumors) is accurate, but much experience is required for the cytodiagnosis of other tumor types. The majority of liver malignancies is metastatic in origin and poses no diagnostic problems. Pathologists also should be familiar with the cytology of hepatocellular carcinoma as the population of Asian immigrants in North America is increasing. Most of the pancreatic tumors are ductal adenocarcinomas, which can be diagnosed cytologically. Occasionally, atypical ductal epithelium in chronic pancreatitis may mimic malignancy. Cytodiagnosis of nonduct-cell neoplasms of the pancreas requires experience.