Benign lesions
Benign clear cell tumor (‘sugar’ tumor) It is a rare tumor, occurring in any age as an asymptomatic peripheral nodule. Because of their immunohistochemical and ultrastructural features, they have been supposed to origin from pericytes; anyway, their origin is a matter of discussion. They consist of polygonal cells with clear, glycogen-rich cytoplasm. Cytologic diagnostic features […]
Epithelioid hemangioendothelioma
Epithelioid hemangioendothelioma Hypocellular (in some cases) Isolated, large polymorphous cells with a folded nuclear outline Occasional intranuclear and cytoplasmic inclusions Binucleated and multinucleated giant cells Round irregular nuclei, prominent nucleoli Abundant lacy and hematoxiphilic cytoplasm Immunostains for endothelial markers are usually positive.
Metastatic tumors
Metastatic tumors Colorectal carcinoma Tall (columnar), dark (hyperchromatic) cells and necrosis Breast carcinoma and gastric carcinoma Sig net rin g cells Prostate carcinoma Mic roacini Prominent nucleoli Immu noreactive for Prostatic Specific Antigen and Prostatic Acid Phosphatase Well-differentiated neuroendocrine tumors Eccen trically placed nuclei salt-and-pepper chromatin pattern Abundant granular cytoplasm Single cells, loosely cohesive clusters and rosettes Immunore active for neuroendocrine […]
Hepatoblastoma
Hepatoblastoma It is a rare tumor of infancy. Cytologic smears mimic those from HCC, with larger and more anaplastic cells, or those from small, blue, round cells tumors of childhood.
Solitary cysts
Solitary cysts The simple, unilocular cyst is lined by cuboidal or columnar epithelium resembling biliary epithelium. The aspirated fluid is typically hypocellular and non-diagnostic. The ciliated foregut cyst is unilocular and lined by respiratory-type epithelium. Ciliated columnar cells and mucus cells are seen in cytologic specimens. This benign lesion must be differentiated from bile duct […]
Angiosarcoma
Angiosarcoma It is an uncommon malignant tumor (less than 1% of primary liver malignancies). It is associated with cirrhosis in about one-third of the cases. Many patients have been exposed to polyvinyl chloride or to Thorotrast as a a radiographic contrast agent. Cytologic diagnostic features Elongated cells, isolated or in tightly cohesive clusters and syncitia […]
Cirrhosis
Cirrhosis Cirrhosis, whether caused by alcoholic hepatitis, viral hepatitis or other diseases, results in a disruption of the normal liver architecture, with bands of fibrosis separating nodules of regenerating hepatocytes. Some nodules can be larger and raise the suspicious of a malignancy, such as hepatocellular carcinoma. As a matter of fact, patients with cirrhosis are […]
Focal nodular hyperplasia
Focal nodular hyperplasia It is a benign lesion, presenting as a solitary nodule or, less commonly, as several nodules. Most patients are women in their third or fourth decade. The lesions usually have a central scar and are composed of nodules of hepatocytes, which are separated from one another by radiating fibrous septae containing bile […]
Liver cell adenoma
Liver cell adenoma It is an uncommon benign tumor, usually occurring in women under the age of 30 who have a history of use of oral contraceptives. Histologically, they are only composed of hepatocytes. Cytologic diagnostic features Predominance of hepatocytes Mild nuclear atypia Abundant cytoplasm Normal N/C ratio Differential diagnosis Normal liver Focal nodular hyperplasia […]
Anatomy and histology of the liver
Anatomy and histology of the liver The liver lobules are the structural and functional units of the liver. The lobule is surrounded by 6 portal tracts and centered on the centrolobular vein, which is a terminal twig of the hepatic vein. The portal vein ramifications in the portal tracts give off a series of branches […]