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 […]

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 […]

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.

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 […]

Bile duct hamartoma and adenoma

Bile duct hamartoma and adenoma The bile duct hamartoma (von Meyenberg complex) is characterized by multiple small nodules composed of haphazardly arranged bile ductules and fibrous stroma. The bile duct adenoma is a solitary, small subcapsular nodule. Cytologic diagnostic features Hypocellular specimens Benign ductal cells in tubules and cohesive sheets Benign hepatocytes

Fine needle aspiration (FNA)

Fine needle aspiration (FNA) Fine needle aspiration (FNA) is used mainly for the diagnosis of focal lesions of the liver, whereas percutaneous biopsy with a large-core needle is preferred for diagnosing diffuse liver diseases (such as hepatitis and cirrhosis), for which architectural details are important. Sensitivity of cytology is higher than the one of histology, […]


Hemangioma It is the most common benign tumor of the liver. It is composed of dilated vascular spaces lined by endothelial cells. When a spindle cell lesion is observed on FNA, it is most likely a hemangioma. In some cases only blood or benign hepatocytes are observed. Cytologic diagnostic features Blood Hepatocytes Three-dimensional arcades of […]

Normal cells

Normal cells Normal cells are commonly seen in the cytologic specimens of the liver. Hepatocytes, bile duct epithelium, Kupffer cells and sheets of mesothelial cells are often observed in the cytologic preparations. Hepatocytes – cytologic features Large polygonal cells Isolated cells, thin ribbons (trabeculae), or larger tissue fragments Centrally placed, round to oval nuclei, binucleation, […]