Expression of estrogen and progesterone receptors and inhibin-alpha in hepatobiliary cystadenoma: an immunohistochemical study

Mucinous Cystic Neoplasms of the Liver: Epidemiology, Diagnosis, and Management

Mucinous cystic neoplasms (MCNs) are rare tumors of the liver, occasionally seen in the biliary tree. Epidemiologic data are limited by their indolence and recent changes to diagnostic criteria. They are considered premalignant lesions capable of invasive behavior. While their etiology remains unknown, their female predominance, age of onset, and hormonally responsive ovarian-type stroma suggest ectopic organogenesis during embryologic development. MCNs can typically be recognized on imaging; yet, invasiveness is often indeterminate, and percutaneous tissue biopsy has shown limited value. Therefore, complete excision is recommended for all lesions as focal malignant transformation and metastatic disease has been reported.

Imaging of Rare Primary Malignant Hepatic Tumors in Adults With Histopathological Correlation

Hepatocellular carcinoma and cholangiocarcinoma are the most common primary liver malignancies in adults (comprising >85%); however, liver is also host to some unusual primary malignant tumors. Some of these tumors show distinct demographic, clinicopathologic, and imaging features. Imaging features of these uncommon primary malignant liver tumors are presented with an attempt to correlate them with histopathology.

Spectrum of multilocular cystic hepatic lesions: CT and MR imaging findings with pathologic correlation

A multilocular cystic hepatic lesion detected at computed tomography (CT) and magnetic resonance (MR) imaging is a common but nonspecific radiologic finding that can cause potential challenges for differential diagnosis. This imaging pattern may be observed in a wide spectrum of common and uncommon neoplastic or nonneoplastic entities. Neoplastic lesions include cystadenoma, cystadenocarcinoma, hepatocellular carcinoma (HCC), metastases, mesenchymal hamartoma, and inflammatory myofibroblastic tumor. Nonneoplastic lesions include hepatic abscess, echinococcal cyst, intrahepatic hematoma, and biloma. The multiple coalescent cysts seen in polycystic liver disease may exhibit an imaging pattern similar to that of a multilocular cystic lesion. Mural nodularity, irregular thickness of the septa, ragged inner surface, and typical enhancement pattern in the solid portion of the lesion are often indicative of malignancy, although multilocular primary or secondary malignant tumors are uncommon. Recognition of the more common necrosis or cystic change of HCC and metastases induced by locoregional or systemic treatment also is important. The nonenhanced cystic component may be composed of different types of fluids (eg, serous, mucinous, proteinaceous, hemorrhagic, bilious, or mixed) or spontaneous or treatment-related necrosis, whereas the septa may be formed by a wide range of tissues depending on the lesion type. An understanding of the CT and MR imaging findings of these lesions and their respective pathologic correlation aids in accurate diagnosis.

Cystic tumors of the liver: on the problems of diagnostic criteria

We report on three cases of cystic neoplasms of the liver with mucinous epithelium. Case 1 showed a low-grade cystic neoplasm with ovarian-like stroma (OS). Case 2 showed a low-grade cystic neoplasm without OS, and case 3 showed a high-grade cystic neoplasm without OS. In all three cases, bile duct communication (BDC) was absent. Currently, pancreatic mucinous cystic neoplasm (MCN) and intraductal papillary mucinous neoplasm of the pancreas (IPMN) are clearly distinguishable. However, MCN of the liver and intraductal papillary neoplasm of the bile duct (IPN-B) are not as easily distinguished. According to the latest WHO classification (2010), these conditions are classed as typical MCN of the liver, MCNs of the liver without OS, or IPN-Bs without BDC. The clinicopathological differences between MCN without OS and IPN-B without BDC are controversial. We present three cases describing these presentations and discuss the difficulties related to the diagnostic criteria used to distinguish between MCN of the liver and IPN-B.

Biologic and clinical features of benign solid and cystic lesions of the liver

The widespread use of imaging analyses, either routinely or to evaluate symptomatic patients, has increased the detection of liver lesions (tumors and cysts) in otherwise healthy individuals. Although some of these incidentally discovered masses are malignant, most are benign and must be included in the differential diagnosis. The management of benign hepatic tumors ranges from conservative to aggressive, depending on the nature of the lesions. New imaging modalities, increased experience of radiologists, improved definition of radiologic characteristics, and a better understanding of the clinical features of these lesions have increased the accuracy of diagnoses and reduced the need for invasive diagnostic tests. These advances have led to constant adjustments in management approaches to benign hepatic lesions. We review the biologic and clinical features of some common hepatic lesions, to guide diagnosis and management strategies.

[Intrahepatic biliary cystic lesions]

Intrahepatic biliary cysts encompass a large lesional spectrum including hereditary diseases as polycystic liver disease or Caroli's syndrome, malformative lesions as non hereditary Caroli's disease or simple biliary cyst and true neoplastic lesions as cystadenoma or cystadenocarcinoma. The diagnostic approach of these lesions relies firstly on imaging. Nevertheless, the pathologist not exceptionally receives surgical specimens from cystic fenestration or liver specimen resection with one or several cystic lesions. The clues for pathological diagnosis of these lesions have to be known by pathologists. As regards neoplastic cystic lesions, true non-communicating cystic tumors and cystic variants of intraductal biliary tumors have to be distinguished; in both cases, the classification is now identical to the one of pancreatic cystic tumors.

The use of immunohistochemistry in liver tumors

A variety of benign and malignant neoplasms can be encountered in the liver. Hematoxylin and eosin-stained tissue sections alone may not yield sufficient information to definitively diagnose liver tumors; therefore, ancillary studies with immunohistochemical markers can play a crucial role in differentiating the different hepatic neoplasms. The recent development of oncofetoprotein glypican-3 has added to the value of immunohistochemistry in diagnosing liver cancer. This review discusses the immunohistochemical markers used most often in the diagnosis of hepatic tumors.

Pathological aspects of cholangiocarcinoma

Cholangiocarcinoma (CC) arises from the biliary epithelium and in most cases represents adenocarcinoma. Pathomorphological evaluation is of decisive impact for the prognosis and management of CC. Morphological subtyping (histotype; hilar vs peripheral type), TNM classification, lymphatic spread, and resection margin status are of prognostic relevance. Distinction from hepatic metastases may be aided by immunohistology and clinico-pathological correlation. There is convincing evidence of the development of CC via premalignant lesions, especially biliary intraepithelial neoplasia, although further knowledge about the biology and diagnostic definition of these lesions has to be accumulated. Currently, there are no established molecular markers of prognosis or therapeutic target structures to be evaluated at the tissue level. Future progress is needed and expected in novel differential diagnostic and predictive markers, in uniform definition of resection margin status and further understanding of molecular and morphological changes in the development of CC.