Combined hepato-cholangiocarcinoma arising in a gallbladder intracystic papillary neoplasm. A new view on so-called "hepatoid adenocarcinoma of the gallbladder"

A 62-year-old female presented with abdominal pain, weight loss of 20 kg in the prior 6 months, and a palpable mass in the right upper quadrant during physical exam. Standard liver tests, including screening for hepatitis B and C and alpha-fetoprotein were negative or within normal limits. Computerized tomography depicted a transmural gallbladder tumor infiltrating into the adjacent liver with an irregular ill-defined mass occupying segments IV-V-VI, measuring 13.0 x 9.2 x 8.5 cm, with a solid-cystic component and heterogeneous captation of endovenous contrast media. Complete surgical resection of the neoplasm was achieved through an extended cholecystectomy and excision of hepatic segments IV, V and VI, with an uneventful follow-up 29 months until now. Morphological and immunohistochemical assessment favored a diagnosis of combined hepatocellular-cholangiocarcinoma arising in a gallbladder intracystic papillary neoplasm with invasive carcinoma. This case raises the hypothesis that the so-called "hepatoid adenocarcinoma of the gallbladder" may presently be better understood as a neoplasm derived from hepatobiliary stem/progenitor cells. Such cells have been recognized in the canals of Hering, in peribiliary glands within the liver and in the extrahepatic biliary tree, and in gallbladder mucosa.

Stem cell therapeutics: potential in the treatment of inflammatory bowel disease

Stem cell therapies may be valuable in treatment of inflammatory bowel disease (IBD). Here we focus on two very different types of stem cells - hematopoietic stem cells and mesenchymal stem cells. Myeloablation and hematopoietic stem cell transplantation alter host immune response by reconstituting the recipient's blood cell lines with donor cells. Autologous hematopoietic reconstitution may "reboot" mucosal immunity to a normal baseline state, but does not alter any underlying genetic predisposition to IBD. In contrast, allogeneic hematopoietic transplantation reconstitutes all blood lineages from a tissue-matched donor who presumably does not have a genetic predisposition to IBD. Compared with autologous hematopoietic transplantation, allogeneic hematopoietic transplantation carries a much greater risk of complications, including graft-versus-host disease. Mesenchymal stem cells can give rise to cartilage, bone and fat in vitro, but do not reconstitute hematopoiesis after transplantation. Systemically infused mesenchymal stem cells appear to favorably downregulate host immune responses through poorly understood mechanisms. In addition, mesenchymal stem cells may be applied topically to help close fistulas associated with Crohn's disease. For all of these stem cell therapy applications for IBD, only cases and small series have been reported. Larger clinical trials are planned or ongoing.

Treatment rates in patients with chronic hepatitis C after liver biopsy

Hepatitis C virus (HCV) infection is a major health problem in the United States. Only about 30% of patients infected with HCV are being treated despite the development of increasingly effective therapies. The aims of this study were to determine the rate of treatment for patients with HCV after undergoing liver biopsy, to assess any change in their treatment rates over recent years and to delineate the reasons for nontreatment. We retrospectively reviewed the charts of all HCV patients who had liver biopsies at Beth Israel Medical Center, New York between 1998 and 2002. The data gathered included patient demographics, stage of liver fibrosis, insurance information, treatment history and reasons for nontreatment. There were 433 liver biopsies done for chronic hepatitis C between 1998 and 2002. Of those, 267 (61%) were men. The mean age was 47 years (range, 18-72). Only 159 (37%) patients were treated after liver biopsy. Overall there were no significant differences in the treatment rates from 1999 to 2002. The common reasons for nontreatment included minimal/mild disease (stage 0-1 fibrosis, 38%), lost to follow-up or noncompliance (31%) and patient refusal (22%). Older patients more frequently had co-morbid conditions (P = 0.009). Younger age and female gender correlated with minimal disease on biopsy (P = 0.004 and 0.01, respectively). Men were lost to follow-up more frequently than women (37%vs 22%, P = 0.01). Multivariate analysis showed that age and gender were both independent predictors of minimal disease. Patients having Medicaid with or without Medicare were significantly more likely to be treated than patients with private or commercial insurance or patients with Medicare alone. A minority of HCV infected patients were treated even after having undergone liver biopsy. The proportion of HCV patients being treated after liver biopsy has been relatively stable despite advances in therapeutic success. Liver histology frequently identified patients with mild disease in whom antiviral therapy was deemed not urgent.

Postmodern biology: (adult) (stem) cells are plastic, stochastic, complex, and uncertain

This chapter will discuss recent findings regarding cell plasticity and stem cell behavior, focusing on ways in which experimental design, observer interference, and inherent stochasticity and complexity are serving to create a new, postmodern biology. The chapter will summarize: (a) the four recognized pathways whereby cell plasticity occurs physiologically; (b) recent findings regarding unexpected epigenetic reversibility of gene restrictions that provide the mechanistic core of plasticity; (c) current evidence for the stochastic nature of gene expression and, therefore, of cell fate decisions. It will be noted that stochastic, however, does not imply completely random; rather, constrained randomness, intermediate between rigid determinism and complete disorder is what is usually seen experimentally. Possible sources of such constrained disorder, from a biomolecular point of view, will be discussed. The chapter will conclude with discussions of how these findings contribute to a Complexity Theory formulation of the body as self-organizing emergence of interacting biomolecules and the implications of such concepts for design and interpretation of experimental results (i.e., a cellular version of Heisenbergian uncertainty).

Prospects for cell-based therapies for liver disease

Liver parenchymal maintenance and regeneration after injury are physiologically supported by 3 cell compartments: mature liver cells, intra-organ stem cells such as cells of the proximal biliary tree and periductal cells, and extra-organ stem cells from the circulation and the bone marrow. In the latter case, hepatocyte derivation from circulating cells (plasticity) can arise via direct transdifferentiation (site specific, receptor/ligand dependent) or by fusion of circulating cells with pre-existing hepatocytes. Other non-physiologic stem cells, such as mesenchymal stem cells from the bone marrow and embryonic stem cells, may be potentially used in treatment of inherited and acquired liver diseases. This review updates our current understanding of these various cell populations and of possible approaches to their future therapeutic uses in cell transplantation, bioartificial liver devices, cytokine/chemokines manipulation of physiological repair pathways, and gene therapy.

Hepatic 'stem cell' malignancies in adults: four cases

AIMS

Combined hepatocellular/cholangiocarcinomas have been explained by some investigators as bidirectional differentiation of neoplastic progenitor cell populations. The presence of hepatic progenitor cells has now been confirmed in humans, though whether they can give rise to malignant tumours has not been confirmed. We report four cases of small tumours identified in livers with features of chronic hepatitis which may suggest a role for malignant transformation of hepatic stem cells in hepatic malignancies.

METHODS

Tumour samples were studied from four patients by histochemistry and immunohistochemistry.

RESULTS

Two patients had chronic hepatitis B, one had chronic hepatitis C and chronic alcoholic liver injury, and one had non-B non-C chronic hepatitis. Stages of disease ranged from portal fibrosis to cirrhosis. All tumours contained undifferentiated cells with morphological and immunohistochemical features that would be expected of hepatic progenitor cells. These cells merged with both hepatocellular carcinoma and cholangiocarcinoma components as well as with mature appearing hepatocytes within the tumours.

CONCLUSION

We suggest that these tumours are of hepatic progenitor cell origin, supporting the concepts that human hepatocarcinogenesis can be based on transformation of progenitor cells and that such a process may underlie development of some mixed hepatocellular/cholangiocarcinomas and dysplastic nodules.

Toward a new paradigm of cell plasticity

The standard paradigm of embryologic development and adult tissue reconstitution posits unidirectional, hierarchical lineages. The presumed mechanisms underlying these differentiative pathways are gene restrictions, such as methylation and heterochromatin formation, which are commonly described as irreversible. However, recent discoveries regarding multi-organ stem cells demonstrate that 'true plasticity' exists, with cells of one organ turning into cells of other organs, including differentiative transformations that cross barriers between tissues derived from different primitive germ layers. These findings, along with earlier experiments into heterokaryon formation and longstanding recognition of reactive and neoplastic lesions in humans and animals, suggest that lineage pathways are not, in fact, unidirectional. Moreover, physiologic mechanisms of reversal of gene restrictions have been recognized. Therefore, in response to these observations, we suggest a new paradigm of cell plasticity, elucidating three guiding principles of 'genomic completeness', 'uncertainty of cell characterization', and 'stochastic nature of cell origins and fates'. These principles imply a change in the way data can be interpreted and could alter subsequent hypothesis formation. This new paradigm will hopefully lead us forward to a more flexible and creative exploration of the potential of adult vertebrate cells.

Multi-organ, multi-lineage engraftment by a single bone marrow-derived stem cell

Purification of rare hematopoietic stem cell(s) (HSC) to homogeneity is required to study their self-renewal, differentiation, phenotype, and homing. Long-term repopulation (LTR) of irradiated hosts and serial transplantation to secondary hosts represent the gold standard for demonstrating self-renewal and differentiation, the defining properties of HSC. We show that rare cells that home to bone marrow can LTR primary and secondary recipients. During the homing, CD34 and SCA-1 expression increases uniquely on cells that home to marrow. These adult bone marrow cells have tremendous differentiative capacity as they can also differentiate into epithelial cells of the liver, lung, GI tract, and skin. This finding may contribute to clinical treatment of genetic disease or tissue repair.

Hepatocellular carcinoma and dysplastic nodules in patients with cirrhosis: prospective diagnosis with MR imaging and explantation correlation

PURPOSE

To determine the sensitivity and specificity of magnetic resonance (MR) imaging for detection of hepatocellular carcinoma (HCC) and dysplastic nodules (DNs) by using explantation correlation in patients with cirrhosis and no known HCC.

MATERIALS AND METHODS

Seventy-one patients without a known history of HCC who underwent MR imaging and subsequent transplantation within 90 days were examined. Breath-hold turbo short inversion time inversion-recovery and/or T2-weighted turbo spin-echo MR images were obtained. Dynamic two- or three-dimensional gadolinium-enhanced gradient-echo MR images were obtained in the hepatic arterial, portal venous, and equilibrium phases. Prospective MR image interpretations were compared directly with explanted liver pathologic results.

RESULTS

Eleven (15%) of 71 patients had hepatic malignancies; MR imaging enabled diagnosis of tumor in six (54%) of 11 patients. On a lesion-by-lesion basis, MR imaging depicted 11 of 20 hepatic neoplasms, for an overall sensitivity of 55%. MR imaging depicted four (80%) of five lesions larger than 2 cm, six (50%) of 12 lesions 1-2 cm, and one (33%) of three lesions smaller than 1 cm. MR imaging depicted only nine (15%) of 59 DNS: The specificities of MR imaging for detection of HCC and DNs on a per patient basis were 60 (86%) of 70 patients and 53 (85%) of 62 patients, respectively.

CONCLUSION

MR imaging is insensitive for the diagnosis of small (<2-cm) HCCs and DNS:

Siderotic nodules in the cirrhotic liver at MR imaging with explant correlation: no increased frequency of dysplastic nodules and hepatocellular carcinoma

PURPOSE

To determine the sensitivity of magnetic resonance (MR) imaging for detection of siderotic nodules in patients with cirrhosis and whether the frequency of hepatocellular carcinoma (HCC) and dysplastic nodules is greater if siderotic nodules are present.

MATERIALS AND METHODS

MR imaging (1.5 T) was performed within 0-117 days (mean, 30 days) before liver transplantation in 77 patients. Two readers retrospectively evaluated gradient-echo (GRE) (echo time [TE], > or = 9 and 4-5 msec) and turbo short inversion time inversion-recovery or T2-weighted images for low-signal-intensity nodules. Whole-explant pathologic correlation was available in every case.

RESULTS

At explantation, 28 (36%) of 77 patients had HCC, 25 (32%) had dysplastic nodules, and nine (12%) had both; 35 (45%) patients had siderotic nodules. The sensitivity of GRE imaging with 9-msec or longer TE for the detection of siderotic nodules was 80% (28 of 35) but decreased to 31% (11 of 35) with 4-5-msec TE. Frequency of HCC was not significantly higher (P =.27) in patients with (43% [15 of 35]) than in patients without (31% [13 of 42]) siderotic nodules. Frequency of dysplastic nodules also was not significantly higher (P =.42) in patients with (37% [13 of 35]) than in patients without (29% [12 of 42]) siderotic nodules.

CONCLUSION

Sensitivity of MR imaging for the detection of siderotic nodules was improved with use of GRE pulse sequences with longer TEs of 9 msec or greater (80%) versus 4-5 msec (31%); however, there was no significant increased frequency of HCC or dysplastic nodules in patients with pathologically proved siderotic nodules.

Siderotic nodules at MR imaging: regenerative or dysplastic?

OBJECTIVE

To determine if iron containing "siderotic" nodules detected at magnetic resonance (MR) imaging are regenerative (RN) or dysplastic (DN) and to attempt to identify features that may distinguish them.

MATERIAL AND METHODS

MR imaging (1.5 T) was performed on 77 cirrhotic patients who underwent orthotopic liver transplantation within 0-117 days (mean 30 days) of MR imaging. Two readers retrospectively evaluated breath-hold gradient-echo pulse sequences (echo time > or =9.0 ms, flip angle < or =45 degrees) for the presence of hypointense nodules, which were classified as micronodular (< or =3 mm), macronodular (>3 mm), or mixed. Nodule distribution was classified as focal (<5), scattered (5-20), or diffuse (>20) per slice. Thin section pathologic correlation was available in all cases, and Prussian blue iron stains were performed.

RESULTS

Of 35 patients with pathologically proven siderotic nodules, 10 (29%) had at least 2 siderotic DN. MR detected siderotic nodules in 10 of 10 (100%) patients with siderotic DN and RN, and in 18 of 25 patients (72%) with siderotic RN only.

CONCLUSION

Siderotic RN cannot be reliably distinguished from siderotic DN with MR imaging, and therefore the widely used term "siderotic regenerative nodule" should be avoided and replaced by "siderotic nodule."

Liver from bone marrow in humans

It has been shown in animal models that hepatocytes and cholangiocytes can derive from bone marrow cells. We have investigated whether such a process occurs in humans. Archival autopsy and biopsy liver specimens were obtained from 2 female recipients of therapeutic bone marrow transplantations with male donors and from 4 male recipients of orthotopic liver transplantations from female donors. Immunohistochemical staining with monoclonal antibody CAM5.2, specific for cytokeratins 8, 18, and 19, gave typical strong staining of hepatocytes, cholangiocytes, and ductular reactions in all tissues, to the exclusion of all nonepithelial cells. Slides were systematically photographed and then restained by fluorescence in situ hybridization (FISH) for X and Y chromosomes. Using morphologic criteria, field-by-field comparison of the fluorescent images with the prior photomicrographs, and persistence of the diaminiobenzidene (DAB) stain through the FISH protease digestion, Y-positive hepatocytes and cholangiocytes could be identified in male control liver tissue and in all study specimens. Cell counts were adjusted based on the number of Y-positive cells in the male control liver to correct for partial sampling of nuclei in the 3-micron thin tissue sections. Adjusted Y-positive hepatocyte and cholangiocyte engraftment ranged from 4% to 43% and from 4% to 38%, respectively, in study specimens, with the peak values being found in a case of fibrosing cholestatic recurrent hepatitis C in one of the liver transplant recipients. We therefore show that in humans, hepatocytes and cholangiocytes can be derived from extrahepatic circulating stem cells, probably of bone marrow origin, and such "transdifferentiation can replenish large numbers of hepatic parenchymal cells.

Dysplastic nodules and hepatocellular carcinoma: sensitivity of digital subtraction hepatic arteriography with whole liver explant correlation

PURPOSE

The purpose of this work was to determine the sensitivity of hepatic digital subtraction arteriography (DSA) for the detection of hepatocellular carcinoma (HCC) and dysplastic nodules (DNs) when compared with pathological findings from whole liver explants.

METHOD

Twenty-one patients 30-72 years old (mean 54 years) with cirrhosis and known or clinically suspected HCC (20 prior to chemoembolization) underwent hepatic DSA with subsequent transplantation within 80 days (mean 32 days). The prospective DSA report was compared with pathologic findings from explanted livers.

RESULTS

Overall, DSA detected 31 of 95 HCC lesions for a sensitivity of 33%. Of these 31 lesions, 28 were hypervascular and 3 were hypovascular. DSA detected all six HCCs measuring >5 cm, all six HCCs measuring 3-5 cm, and all five HCCs 2-3 cm, resulting in a sensitivity of 100% (17/17) for HCC >2 cm. DSA detected 7 of 18 HCCs measuring 1-2 cm (sensitivity 39%) and 7 of 60 HCCs < or =1 cm (sensitivity 12%). Overall sensitivity for DSA in detection of HCC < or =2 cm was 18% (14/78 lesions). None of 17 DNs (0.2-1.5 cm in size) was identified on DSA.

CONCLUSION

DSA is insensitive to small HCC (< or =2 cm), carcinomatosis arising within nodules, and DN.

Focal lesions in the cirrhotic liver: high resolution ex vivo MRI with pathologic correlation

Cirrhosis is a progressive, diffuse process of liver fibrosis that is characterized by architectural distortion and the development of a spectrum of nodules ranging from benign regenerative nodules to premalignant dysplastic nodules to overtly malignant hepatocellular carcinoma. The purpose of this essay is to demonstrate the ex vivo MR and pathology findings of these nodules as well as other masses that can be seen in the cirrhotic liver. The optimal conditions under which ex vivo imaging can be performed allow greater spatial resolution than that achieved with in vivo imaging, without artifacts that may degrade image quality. Clearly, contrast-enhanced MRI is essential for both the diagnosis and the characterization of focal lesions in the cirrhotic liver. However, the use of ex vivo imaging precludes the evaluation of these important in vivo pulse sequences.

Derivation of hepatocytes from bone marrow cells in mice after radiation-induced myeloablation

Following a report of skeletal muscle regeneration from bone marrow cells, we investigated whether hepatocytes could also derive in vivo from bone marrow cells. A cohort of lethally irradiated B6D2F1 female mice received whole bone marrow transplants from age-matched male donors and were sacrificed at days 1, 3, 5, and 7 and months 2, 4, and 6 posttransplantation (n = 3 for each time point). Additionally, 2 archival female mice of the same strain who had previously been recipients of 200 male fluorescence-activated cell sorter (FACS)-sorted CD34(+)lin(-) cells were sacrificed 8 months posttransplantation under the same protocol. Fluorescence in situ hybridization (FISH) for the Y-chromosome was performed on liver tissue. Y-positive hepatocytes, up to 2.2% of total hepatocytes, were identified in 1 animal at 7 days posttransplantation and in all animals sacrificed 2 months or longer posttransplantation. Simultaneous FISH for the Y-chromosome and albumin messenger RNA (mRNA) confirmed male-derived cells were mature hepatocytes. These animals had received lethal doses of irradiation at the time of bone marrow transplantation, but this induced no overt, histologically demonstrable, acute hepatic injury, including inflammation, necrosis, oval cell proliferation, or scarring. We conclude that hepatocytes can derive from bone marrow cells after irradiation in the absence of severe acute injury. Also, the small subpopulation of CD34(+)lin(-) bone marrow cells is capable of such hepatic engraftment.

The canals of Hering and hepatic stem cells in humans

Small, extraportal, hepatic parenchymal cells, positive for biliary-type cytokeratins, may represent hepatic stem cells, canals of Hering (CoH), and/or ductal plate remnants. We evaluated these cells 3 dimensionally in normal human liver and massive necrosis. Tissues from normal human livers and from 1 liver with acetaminophen-induced massive necrosis were serially sectioned, immunostained for cytokeratin 19 (CK19), and sequentially photographed. Images were examined to determine 3-dimensional relationships among CK19-positive cells. Immunostains for other hepatocyte and progenitor cell markers were examined. In normal livers, intraparenchymal CK19-positive cells lined up as linear arrays in sequential levels. One hundred of 106 (94.3%) defined, complete arrays within levels examined, most having 1 terminus at a bile duct, the other in the lobule, beyond the limiting plate. In massive necrosis, there were 767 individual CK19-positive cells or clusters around a single portal tract, 747 (97.4%) of which were spatially related forming arborizing networks connected to the interlobular bile duct by single tributaries. C-kit was positive in normal CoH. CK19 co-expressed with HepPar1, c-kit, and alpha-fetoprotein (AFP) in parenchymal cells in massive necrosis. Small, extraportal, biliary-type parenchymal cells represent cross-sections of the CoH that radiate from the portal tract, usually extending past the limiting plate into the proximate third of the hepatic lobule. The 3-dimensional structure of ductular reactions in massive necrosis suggests that these reactions are proliferations of the cells lining the CoH. Therefore, the CoH consist of, or harbor, facultative hepatic stem cells in humans.

Dysplastic nodules in cirrhotic liver: arterial phase enhancement at CT and MR imaging--a case report

In a 65-year-old woman with cirrhosis, biphasic helical computed tomography (CT) and multiphase gadolinium-enhanced magnetic resonance (MR) imaging depicted 11 hepatic nodules that enhanced homogeneously during the hepatic arterial phase. At pathologic examination, all lesions were dysplastic nodules with unpaired hepatic arteries within. Hepatic arterial phase enhancement of cirrhotic nodules at CT and MR imaging is not diagnostic of hepatocellular carcinoma but may occur in dysplastic nodules. Results of a single biopsy yielding hepatocellular carcinoma may not be applicable to other nodules that enhance similarly.

Differential diagnosis of hepatocellular nodular lesions

The great advances in radiologic imaging of the last two decades have focused attention on hepatic nodular lesions. Various entities with a nodular appearance are predominantly composed of hepatocytes or tumor cells of hepatocytic origin, including benign and malignant neoplasms as well as tumorlike lesions. Differential diagnosis of these nodules can often be difficult, especially in the limited material of a needle biopsy specimen. The histological features that can be of help in this regard are the focus of this review. In noncirrhotic livers, differential diagnoses include liver cell adenoma, focal nodular hyperplasia, large regenerative nodule, nodular regenerative hyperplasia, partial nodular transformation, compensatory hyperplasia, focal fatty change, and well-differentiated hepatocellular carcinoma. Poorly differentiated hepatocellular carcinoma must be distinguished from other malignant tumors, especially metastatic, poorly differentiated adenocarcinoma. In cirrhotic livers, the differential diagnoses include large regenerative nodule, focal fatty change, low-grade dysplastic nodule, high-grade dysplastic nodule, and hepatocellular carcinoma.

Immunohistochemical evaluation of hepatoblastomas with use of the hepatocyte-specific marker, hepatocyte paraffin 1, and the polyclonal anti-carcinoembryonic antigen

The distinction of hepatoblastoma, especially the embryonal type, from other small, round-cell tumors of childhood can sometimes be difficult. Polyclonal anticarcinoembryonic antigen (pCEA) and Hepatocyte Paraffin 1 (Hep Par 1) are immunohistochemical markers that are useful in the diagnosis of hepatocellular carcinomas. We immunohistochemically studied pCEA, monoclonal CEA (mCEA), and Hep Par 1 on 12 hepatoblastomas (3 fetal type, 2 embryonal type, and 7 mixed epithelial type). In addition, we studied the expression of Hep Par 1 on 27 other selected childhood tumors, including 1 hepatocellular carcinoma, 5 germ-cell tumors, 4 peripheral neuroectodermal tumors/Ewing's sarcomas, 3 rhabdomyosarcomas, 5 neuroblastomas, 2 rhabdoid tumors, 3 lymphomas, and 4 Wilms' tumors. All of the hepatoblastomas expressed Hep Par 1 with a characteristic granular intracytoplasmic pattern that was generally less intense in embryonal-type than in fetal-type hepatoblastomas, perhaps reflecting the degree of hepatocyte differentiation. All of the fetal-type hepatoblastomas expressed pCEA with both an intracytoplasmic and bile canalicular pattern. Embryonal type hepatoblastomas were more likely to be pCEA negative or to show focal or no canalicular pattern of expression, again possibly reflecting the degree of hepatocyte differentiation. All of the hepatoblastomas were mCEA negative. All of the nonhepatoblastomas were Hep Par 1 negative, except for the one hepatocellular carcinoma in this study, which was Hep Par 1 positive. We conclude that Hep Par 1 and pCEA are useful markers for hepatoblastomas, as they have been shown to be in hepatocellular carcinomas.

Immunohistochemical detection of hepatitis C antigen by monoclonal antibody TORDJI-22 compared with PCR viral detection

We sought to determine the sensitivity and specificity of immunohistochemistry using the TORDJI-22 MoAb (BioGenex, San Ramon, Calif), which is specific for the C-100 protein of the hepatitis C virus, compared with reverse transcriptase-polymerase chain reaction (RT-PCR) of tissue for viral RNA. RT-PCR had been performed on 52 fixed tissue specimens. Immunohistochemistry was performed using prediluted antibody with the alkaline phosphatase/fast red (BioGenex) technique. Predigestion with Protease XXIV (BioGenex) and other procedures followed the manufacturer's protocols. Positive immunohistochemistry was narrowly defined as tightly clumped, perinuclear red granules in hepatocytes. Of the specimens, 28 were positive by RT-PCR. With RT-PCR as the standard of comparison, immunohistochemistry yielded a sensitivity of 70% and specificity of 84%. Positive cells, when present, were usually very rare. With stringent criteria, immunohistochemistry with the TORDJI-22 monoclonal antibody is a very specific, fairly sensitive diagnostic test for hepatitis C virus in fixed liver tissues.

Neoangiogenesis and sinusoidal "capillarization" in dysplastic nodules of the liver

The blood supply of hepatocellular carcinoma (HCC) is primarily arterial. Recent studies reported differences of vascular, especially arterial, supply among low- and high-grade dysplastic nodules and HCC. We assessed arterialization using monoclonal antibody specific for smooth muscle actin as well as simultaneous changes in sinusoidal capillarization in cirrhotic nodules, dysplastic nodules, and HCC. We immunohistochemically stained 56 cirrhotic nodules, 20 low-grade dysplastic nodules, 27 high-grade dysplastic nodules, and 20 HCCs for alpha smooth muscle actin (to identify unpaired arteries (i.e., arteries not accompanied by bile ducts) and CD34 (indicating sinusoidal capillarization). Distribution and number of unpaired arteries and distribution of sinusoidal capillarization were graded semiquantitatively. Unpaired arteries were rare in cirrhotic nodules, significantly more common in dysplastic nodules of both types (p < 0.00001), and most common in HCC. Sinusoidal capillarization was least common in cirrhotic nodules, significantly more common in dysplastic nodules (p < 0.0035), and most common in HCC. No topographic relationship between unpaired arteries and sinusoidal capillarization was identified. These findings showed that (1) distributions of sinusoidal capillarization and unpaired arteries in dysplastic nodules are intermediate between those in cirrhotic nodules and HCC, supporting dysplastic nodules as premalignant lesions; (2) unpaired arteries are histologically useful for distinguishing dysplastic nodules from large cirrhotic nodules; and (3) areas of sinusoidal capillarization within dysplastic nodules are unrelated to location of arterialization.

Hepatic stellate cell activation in dysplastic nodules: evidence for an alternate hypothesis concerning human hepatocarcinogenesis

We have previously suggested that dysplastic nodules (also referred to as "adenomatous hyperplasia" or "macroregenerative nodules"), likely precursors of hepatocellular carcinoma (HCC), develop as an infiltrating clonal expansion, in advance of or parallel to cirrhosis. As part of this hypothesis, to explain aspects of their gross and microscopic appearance, we suggested that dysplastic nodules are resistant to the scarring process affecting the rest of the liver. We sought to test this hypothesis by examining the distribution of activated hepatic stellate cells (HSCs), the hallmark of hepatic scarring, in cirrhotic nodules, dysplastic nodules and HCC. We immunohistochemically stained 56 cirrhotic nodules, 20 low grade dysplastic nodules, 27 high grade dysplastic nodules, and 20 HCCs with monoclonal antibodies against alpha-smooth muscle actin to identify activated HSCs. Distribution and number of HSCs were graded semiquantitatively (0 to 4+). In our results, HSCs were significantly less widespread in dysplastic nodules than in cirrhotic nodules or in HCCs (both: p < 0.00001). HSCs were also more prominent in the periphery of dysplastic nodules than in the center, though still fewer in number than in cirrhotic nodules. In conclusion, the low number of activated HSCs in dysplastic nodules, compared to both cirrhotic nodules and HCC, supports our hypothesis concerning dysplastic nodule development: that they arise as clonal expansions of neoplastic hepatocytes in advance of, or parallel to, the development of cirrhosis.

Detection of hepatitis C virus RNA sequences in hepatocellular carcinoma and its precursors by microdissection polymerase chain reaction

OBJECTIVE

Chronic hepatitis C virus (HCV) infection is frequently associated with the development of hepatocellular carcinoma (HCC), but the mechanism of malignant transformation is unknown. To analyze the association of HCV with HCC, we developed a microdissection technique for the detection by polymerase chain reaction of positive (genomic)- and negative (replicative)-strand HCV RNA in histologically confirmed HCC and the surrounding cirrhotic and macroregenerative nodules.

MATERIALS AND METHOD

Five HCCs and one macroregenerative nodule and the surrounding cirrhotic liver tissues of all cases were selected for this study. The method entails extraction of RNA from selected areas of formalin-fixed, hematoxylin-stained histologic sections, followed by strand-specific reverse-transcription double polymerase chain reaction and Southern blotting.

RESULTS

Positive- and negative-strand HCV RNA sequences were detected in five of six tumors and the surrounding cirrhotic livers.

CONCLUSIONS

These results verify the method of polymerase chain reaction detection of HCV RNA from histologically defined, selected lesions. In addition, the findings suggest that HCV RNA persists and replicates in hepatocytes during malignant transformation.

Large-cell change of hepatocytes in cirrhosis may represent a reaction to prolonged cholestasis

Large-cell change of hepatocytes (LCC), also called liver cell dysplasia of large-cell type, is a set of cytologic changes comprising nuclear and cytoplasmic enlargement, nuclear pleomorphism, and multinucleation. This entity is encountered frequently on histologic or cytologic examination of specimens obtained from livers with a variety of chronic diseases and originally was thought to have a premalignant nature. Accumulating evidence, however, now suggests that LCC is merely a reactive change. Having often observed LCC in liver specimens with chronic biliary tract disease, that is, in livers where cholestasis preceded hepatocyte injury, we surmised that LCC may be a result of prolonged cholestasis. To determine whether there was any association between LCC and cholestasis, we examined microscopically a series of 400 nodules from 40 consecutive adult cirrhotic livers, resected on transplantation, and graded LCC and cholestasis semiquantitatively. LCC was present diffusely in cirrhotic nodules of 25 specimens (62.5%). Nine additional specimens (22.5%) had focal mild LCC. Usually, LCC and cholestasis occurred together, in the same cirrhotic nodules and in the same areas of nodules. There was a statistically significant association between the presence and grade of LCC and those of cholestasis (p < 0.0001; chi-square test). Within etiological categories of cirrhosis (chronic hepatitis; n = 28; alcoholic liver disease; n = 6; biliary disease: n = 6), the significance was maintained. We conclude that, in cirrhosis of different etiologies, LCC may represent a reactive change that results from prolonged cytoplasmic cholestasis.

Dysplastic nodules and hepatocellular carcinoma: thin-section MR imaging of explanted cirrhotic livers with pathologic correlation

PURPOSE

To evaluate detection and characterization of hepatocellular nodules in fresh whole explanted cirrhotic livers at thin-section magnetic resonance (MR) imaging.

MATERIALS AND METHODS

T1-weighted spin-echo and T2-weighted fast spin-echo MR imaging (5-mm-thick sections) were performed in a head coil at 1.5 T in the whole cirrhotic livers of 28 consecutive patients within 4 hours of explantation. MR imaging findings were correlated with findings at pathologic examination, and new international terminology was used to classify the hepatocellular nodules.

RESULTS

At pathologic examination, 42 suspect (other than regenerative) nodules were identified in 11 patients. MR imaging depicted 41 of 42 (98%) of these nodules (five of five hepatocellular carcinomas [HCCs {diameter, > or = 2 cm}], 10 of 10 small HCCs [diameter, < 2 cm], two of two dysplastic nodules with subfoci of HCC, three of three high-grade dysplastic nodules, and 21 of 22 low-grade dysplastic nodules. Lesions demonstrated the following combinations of signal intensity characteristics on thin-section T1- and T2-weighted images, respectively: HCC, hyperintense, hypointense (n = 3); hyperintense, hyperintense (n = 1); hypointense, isointense (n = 1). Small HCC, hyperintense, hypointense (n = 7); hypointense, hyperintense (n = 2); hyperintense, hyperintense (n = 1). Both dysplastic nodules with subfoci of HCC, hyperintense, hypointense. All seven nonsiderotic low-grade dysplastic nodules, hyperintense, hypointense. All 14 siderotic low-grade dysplastic nodules, hypointense, hypointense. All three high-grade dysplastic nodules, hyperintense, hypointense.

CONCLUSION

The variable signal intensity characteristics of HCCs made reliable diagnosis impossible, but the thinsection unenhanced in vitro MR images were sensitive for detection of HCCs and dysplastic nodules in cirrhotic livers.

Noninvasive and minimally invasive carcinoma ex mixed tumor: a clinicopathologic and ploidy study of 12 patients with major salivary tumors of low (or no?) malignant potential

We studied 12 histologically malignant salivary tumors that showed complete encapsulation or only limited microscopic invasion. Most cases were histologically characterized by atypical and mitotically active luminal cells forming dilated, angular, variably sized glands in the subcapsular region, varying proportions of nonluminal tumor cells, and a background of central fibrosed hyalinized stroma. The appearance is that of a low-grade carcinoma. Focal higher grade carcinoma was superimposed on this histologic data in three cases. Neither recurrences nor metastases were seen in 11 of 12 patients after surgical resection with a follow-up of 1.2 to 13 yrs (mean, 4.2 years). Ploidy studies were performed on the paraffin-embedded tissue in 11 cases and yielded results for 7 cases. Aneuploid cell populations were found in five tumors; two had normal diploid populations; and the ploidy results are not predictive of tumor behavior. This type of salivary gland tumor fits diagnostically within the category of noninvasive and minimally invasive carcinoma ex pleomorphic adenoma (also referred to as in situ and low-grade malignant mixed tumors), a class that requires additional awareness and precise recognition as it signifies a good prognosis after surgical resection.

Low proliferative activity in macroregenerative nodules: evidence for an alternate hypothesis concerning human hepatocarcinogenesis

Macroregenerative nodules are commonly thought to be hyperplastic lesions, deriving both their large size and premalignant potential from an increased proliferative rate. We have previously suggested an alternate model of macroregenerative nodule development in which neither size nor premalignant potential of macroregenerative nodules would depend on increased proliferation. We tested this hypothesis by examining the proliferative activity in macroregenerative and surrounding cirrhotic nodules.

METHODS

Eighteen macroregenerative nodules, including five type I and 13 type II, were immunostained for proliferating cell nuclear antigen (PCNA). Type II macroregenerative nodules included ten with diffuse large (7) or small (3) liver cell dysplasia only and eight containing nodule-in-nodule lesions. Five nodule-in-nodule lesions met the histologic criteria for hepatocellular carcinoma. PCNA labeling indices (PCNA-LIs; percentage positive hepatocyte nuclei/500 randomly counted cells) were determined in macroregenerative nodules and the four largest adjacent cirrhotic nodules. Nodule-in-nodule lesions were assessed separately from the background macroregenerative nodule.

RESULTS

4/5 type I and 12/13 type II macroregenerative nodules (exclusive of NIN lesions) had PCNA-LIs lower than the mean of surrounding cirrhotic nodules. All nodule-in-nodule lesions, whether atypical or overtly malignant, had PCNA-LIs greater than any surrounding nodules. In conclusion, macroregenerative nodules have PCNA-LIs indistinguishable from, and often lower than, surrounding cirrhotic nodules. Increased proliferative activity only occurs with the development of atypia and transition to hepatocellular carcinoma.

CONCLUSION

Macroregenerative nodules derive neither their size nor their premalignant potential from on-going rapid proliferation, a finding consistent with our alternate hypothesis of macroregenerative nodule development.

Detection of hepatitis B and hepatitis C viral sequences in fulminant hepatic failure of unknown etiology

In a significant number of patients, the etiology of fulminant hepatic failure (FHF) is unknown. To determine whether hepatitis B virus (HBV) and hepatitis C virus (HCV) play a role in patients without serologic markers of HBV and HCV infection, the authors examined tissue samples from 15 liver explants with massive hepatic necrosis for the presence of viral sequences by the polymerase chain reaction (PCR). The specimens were derived from nine patients with FHF of unknown etiology; two with serum hepatitis B surface antigen (HBsAg); two with antibodies to HCV; one with antibodies to hepatitis A virus (HAV) and anti-HBc of the IgM class; and one with isoniazid toxicity. Nucleic acids were extracted from frozen liver samples. RNA was used as a template for reverse transcription, followed by double PCR with nested primers for the 5'-untranslated region of HCV. DNA was tested by single PCR for S gene sequences of HBV. Hepatitis B virus sequences were detected in the specimens of the two HBsAg positive patients, the anti-HAV/anti-HBc positive patient, and three of nine patients with FHF of unknown etiology. Hepatitis C virus sequences were present in the explant of one patient with FHF of unknown etiology, but not in the two patients with antibodies to HCV. In two specimens with molecular findings of HBV infection (1 from a patient with serum HBsAg and 1 without), there was immunohistochemical evidence of coinfection or superinfection with hepatitis delta virus (HDV). In conclusion, in this patient population, HBV, alone or with HDV or HAV, causes fulminant hepatic failure more often than HCV infection. However, in the majority of patients, the etiology of fulminant hepatic failure remains unknown.

Macroregenerative (dysplastic) nodules and hepatocarcinogenesis: theoretical and clinical considerations

Over the last decade or so, we have seen the development of an interesting new area of liver pathology, new because advanced imaging techniques coupled with careful screening of population at risk for HCC have focused attention on nodular hepatocellular lesions that have been previously ignored. Careful searching for these nodules has led to the acknowledgment that they are not restricted to the populations in which they were first identified and in which the association with HCC was first made, but are probably a universal phenomenon and one extremely important pathway for the development of HCC. Moving beyond these epidemiological associations, we see that careful consideration of the morphology of these lesions leads to insights into the early stages of human hepatocarcinogenesis, setting the stage for the development of a clinically useful system of nomenclature and, perhaps, new approaches to screening for early HCC. Additional important work lies ahead, as concepts from animal models of hepatocarcinogenesis are applied to these human lesions, molecular approaches to research and diagnostics are applied, and extensive prospective screening and clinicopathologic correlation studies are carried out.

Macroregenerative nodules in a series of adult cirrhotic liver explants: issues of classification and nomenclature

Macroregenerative nodules (MRNs), probably representing a pathway for human hepatocarcinogenesis, are generally classified into type I MRNs (or ordinary adenomatous hyperplasia) and type II MRNs (or atypical adenomatous hyperplasia), on the basis of imprecise definitions of cytological and architectural atypia. It is currently believed that type II MRNs are probably true precursors of hepatocellular carcinoma (HCC), whereas type I lesions may simply represent large regenerative nodules. A series of 155 consecutive adult cirrhotic liver explants were examined for evidence of MRNs, HCC, and liver cell dysplasia (LCD) of large and small cell types, and their appearance, in terms of proposed classification schemes, was reviewed. There was evidence indicating that the presence of either type of MRN was associated with an increased incidence of HCC (all MRNs, P < .00019; type I MRNs, P < .067; type II MRNs, P < .012) compared with cirrhotic livers without MRNs. A subset of younger patients with a large (uncountable) number of MRNs in their livers, who did not show any increased incidence of carcinoma, was identified. Excluding these cases from statistical analysis, all associations were strengthened, implying either that malignant progression had not had time to occur in this younger population or that these nodules were simply large regenerative nodules without malignant potential. MRNs from these livers were histologically indistinguishable from MRNs occurring in more limited numbers, although atypical changes other than large cell type LCD were less frequent. No independent association between LCD of large cell type and HCC was found in the entire series.(ABSTRACT TRUNCATED AT 250 WORDS)

CA19-9 does not predict cholangiocarcinoma in patients with primary sclerosing cholangitis undergoing liver transplantation

The results of liver transplantation in patients with cholangiocarcinoma have been poor. It has been suggested that elevated serum CA19-9 levels predict cholangiocarcinoma in patients with primary sclerosing cholangitis. We analyzed the predictive value of CA19-9 antigen as a marker of cholangiocarcinoma in patients with primary sclerosing cholangitis evaluated for liver transplantation. We reviewed the charts of 26 patients with primary sclerosing cholangitis (stage IV) in whom preoperative serum CA19-9 levels were determined; 22 of 26 underwent liver transplant. Explant specimens were serially sectioned and examined for tumor. In 3 of the 26 patients, cholangiocarcinoma was diagnosed during pretransplantation evaluation; exploratory laparotomy on the last patient showed no evidence of cholangiocarcinoma, and this patient is awaiting transplantation. Twelve of the 26 patients had CA19-9 levels more than double the laboratory reference range (0-37 U/mL) (mean 183.1 +/- 103 U/mL, range 77-415 U/mL). Two of the 12 patients with elevated CA19-9 levels had cholangiocarcinoma. Of the 14 patients with normal levels, two had cholangiocarcinoma. No correlation between elevated CA19-9 and bile duct dysplasia was noted. Sensitivity for serum CA19-9 levels more than twice the reference range is 50%, specificity is 54.5%, positive predictive value is 16.6%. An elevated serum CA19-9 level in a patient with stage IV primary sclerosing cholangitis does not reliably predict coexisting cholangiocarcinoma. Persistently high or rising serum CA19-9 levels do not indicate more urgent need for liver transplantation.

Macroregenerative nodules in cirrhosis are not associated with elevated serum or stainable tissue alpha-fetoprotein

We have explored the relationship of serum alpha-fetoprotein and macroregenerative nodules (MRNs), possible precursor lesions of hepatocellular carcinoma (HCC), and sought to demonstrate alpha-fetoprotein (AFP) expression in these nodules. One hundred and sixty-eight sequential adult cirrhotic resected livers were examined and MRNs were identified by standard criteria. Pretransplant serum AFP was available for 158 of these patients (normal < 20 ng/ml). One hundred and seventy-two randomly selected lesions, including ordinary and atypical MRNs, some containing microfoci of HCC, and HCCs were stained for AFP by immunohistochemistry. In the series, 12 cases had grossly apparent HCCs, four associated with high serum alpha-fetoprotein (p < 0.006). Forty-four cases had MRNs, 32 without grossly apparent HCC. Five of these 32 cases were associated with high serum AFP (not significant). Immuno-staining for AFP was seen in three specimens of HCC and in a cirrhotic nodule from a patient without HCC, but not in MRNs. 1) Neither the presence of MRNs--whether ordinary, atypical, or containing micro-foci of HCC--nor that of gross HCC is ruled out by a normal serum AFP. 2) Elevated serum AFP is not associated with the presence of MRNs. 3) MRNs rarely stain for tissue AFP.

Carcinoma of the breast in postmenopausal hormone user and nonuser control groups

The risk and prognosis of patients with carcinoma of the breast exposed to postmenopausal hormones are controversial. Carcinoma of the breast from 35 postmenopausal women who had taken hormones were compared with carcinomas from age and histologic matched postmenopausal women who had never taken hormones. Hormone users averaged 1.1 fewer pregnancies (p < 0.005) and 1.4 fewer live births (p < 0.0005). In addition, the carcinomas had significantly lower S-phase fractions (5.36 versus 6.77, p > 0.01) and less nodal involvement (1.2 versus 1.9, p < 0.0005). Estrogen and progesterone receptor content, ploidy and deoxyribonucleic acid index were comparable in both groups. These results indicate that hormone users present with slower growing tumors of earlier stage than nonusers, possibly resulting in improved prognosis.

FK506 versus cyclosporine as primary immunosuppressive agent for orthotopic liver allograft recipients. Histologic and immunopathologic observations

We investigated possible explanations for the common occurrence of perivenular lesions in liver allografts of patients on FK506 within a few weeks to several months after OLT. Hematoxylin and eosin-stained sections of pre- and postperfusion biopsy specimens and day 7 post-transplant protocol biopsy specimens from 31 patients, randomly assigned to either FK506 or CsA as primary immunosuppressive agent, were reviewed, and immunohistochemical stains for HLA-DR antigen and S-100 protein were performed by the avidin-biotin peroxidase complex method. The histologic features of cellular rejection in the portal tracts of day 7 posttransplant allograft biopsy specimens from patients on FK506 were milder than those from patients on CsA. Immunohistochemical stains for HLA-DR showed intense positivity in a variety of cell types in day 7 posttransplant specimens from both groups, including sinusoidal-lining cells, bile duct epithelial cells, vascular endothelial cells, inflammatory cells, and occasional injured hepatocytes. Although diffuse lobular staining was seen in the majority of cases in both groups, either with or without rejection, liver biopsy specimens from patients on FK506 showed concentration of positively stained cells in perivenular regions more often, and at a lower overall histologic grade of rejection, than specimens from patients on CsA. There were no differences in the number and distribution of S-100 protein-positive dendritic APC between biopsy specimens from FK506 versus CsA-treated patients, or between specimens with and without cellular rejection in either group. It is suggested that the development of perivenular injury, which is seen frequently in allograft biopsy specimens from patients on FK506 obtained at various intervals after transplantation, may be related to drug toxicity rather than to the process of allograft rejection.

The expression of p53 antigen in primary malignant epithelial tumors of the liver: an immunohistochemical study

We examined the expression of mutant p53 gene products in primary malignant epithelial tumors of the liver. Fourteen of 68 hepatocellular carcinomas, one of seven hepatoblastomas and one of nine intrahepatic cholangiocarcinomas showed nuclear staining for p53 proteins. None of the surrounding non-tumorous tissues expressed nuclear staining. The detection of p53 proteins in tumor cells was significantly higher in hepatocellular carcinomas of Oriental patients (31.6%) compared to non-Orientals (6.7%, p < 0.015). No significant differences were seen in p53 antigen expression between hepatitis B and non-hepatitis B associated hepatocellular carcinomas in Oriental patients. These results suggest a role for other environmental factors, such as aflatoxin, in the etiology of p53 mutation in hepatocellular carcinoma in Oriental patients.

A macroregenerative nodule containing multiple foci of hepatocellular carcinoma in a noncirrhotic liver

We report an incidental small hepatocellular carcinoma in a patient with chronic hepatitis C infection without cirrhosis. The existence of portal triads and the Meyenburg complexes within the lesion and atypical subnodules suggests that the carcinoma has arisen in the context of a macroregenerative nodule rather than the whole nodule being an early, spreading carcinoma. A growing body of evidence supports macroregenerative nodules as being precursor lesions in the development of hepatocellular carcinoma. Although they are generally thought of as being large cirrhotic nodules, this case suggests that they may be lesions that develop in the context of chronic liver disease, parallel to, but independently of, cirrhosis. Moreover, the development of carcinoma within the nodule suggests that macroregenerative nodules may play a role in carcinogenesis in noncirrhotic livers.

DNA image cytometric analysis of macroregenerative nodules (adenomatous hyperplasia) of the liver: evidence in support of their preneoplastic nature

Twenty-eight macroregenerative nodules from 14 cirrhotic patients who underwent orthotopic liver transplantation were evaluated for DNA ploidy by means of image analysis of Feulgen-stained tissue sections. The lesions were classified as type 1 (16 cases) or type 2 (12 cases) on the basis of the absence or presence of cellular or architectural atypia in the nodules. The surrounding cirrhotic nodules were evaluated for liver cell dysplasia. Aneuploid peaks were significantly more frequent in type 2 macroregenerative nodules (58.3%) than in the cirrhotic regenerative nodules (7.1%) (p < 0.007). In addition, aneuploid peaks occurred with increased frequency in type 2 nodules (58.3%) than in type 1 macroregenerative nodules (6.2%) (p < 0.02). Only two aneuploid peaks (14.2%) were found in dysplastic cirrhotic livers. The nuclear area of aneuploid hepatocytes (71.6 microns 2 +/- 10.1%, mean +/- S.D.) differed significantly from that of diploid liver cells (45.4 microns 2 +/- 6.5%) (p < 0.0001). Tetraploid peaks occurred in three type 2 lesions (25%); they were also found in one type 1 macroregenerative nodule (6.2%), one cirrhotic liver without dysplasia (7.1%) and three cirrhotic livers with dysplasia (21.4%). These findings support the notion that macroregenerative type 2 nodules are directly implicated in hepatocarcinogenesis and that their presence should be sought as an indicator of malignant potential in cirrhotic livers.

Biliary cystadenocarcinoma arising in a liver with fibropolycystic disease

Intrahepatic cholangiocarcinoma associated with fibropolycystic disease of the liver and biliary cystadenocarcinoma are rare tumors that are considered distinct entities. We present a case of a malignant tumor with features of hepatic cystadenocarcinoma arising in a background of fibropolycystic disease.

The expression of nuclear lamins in human liver: an immunohistochemical study

The nuclear lamina is a meshwork of intermediate filaments adjacent to the inner nuclear membrane that in mammalian cells is predominantly composed of three proteins: lamin A, lamin B, and lamin C. Because lamin A and C (A-type lamins) expression has been shown to be lacking in several types of undifferentiated or rapidly proliferating cells, we investigated lamin expression in the human liver in conditions with hepatocellular regeneration (cirrhosis of various etiologies and macroregenerative nodules) and in hepatocellular carcinomas of various grades of differentiation. Immunohistochemical stains for A-type lamins and lamin B were performed on frozen tissue sections with the avidin-biotin complex method. Normal and regenerating hepatocytes, biliary epithelial cells (ductal and ductular cells), and hepatocellular carcinoma cells invariably expressed both A-type lamins and lamin B. These findings indicate that in hepatocellular regeneration and malignant transformation the production of both A-type lamins and lamin B is preserved.

Localization of cytomegalovirus antigens in liver allografts over time

Cytomegalovirus (CMV) hepatitis is a common and serious complication of orthotopic liver transplantation. Immunohistochemical studies are the most sensitive methods of diagnosis. We compared immunoperoxidase staining with monoclonal antibodies to CMV immediate early and early antigens with routine hematoxylin-eosin stain. Eleven of 140 liver allograft recipients at our institution had CMV hepatitis identified by hematoxylin-eosin stain on biopsy specimens. We stained serial sections of all previous biopsy specimens and one post-ganciclovir biopsy specimen (when available) from each of these patients. One or both monoclonal antibodies confirmed the original hematoxylin-eosin stain diagnoses. Cytomegalovirus was detected in earlier, hematoxylin-eosin stain-negative biopsy specimens in seven of 11 patients. Detection of immediate early antigen often preceded that of early antigen. Earlier biopsy specimens demonstrated less positive staining, which become more extensive closer in time to the hematoxylin-eosin stain-positive biopsy specimens. Sinusoidal cells became positive earlier than hepatocytes. In one patient occult CMV antigens persisted in biopsy specimens following ganciclovir treatment. We conclude that (1) immunohistochemical staining for CMV antigens can result in earlier detection of viral infection, which may lead to earlier, more effective treatment; (2) CMV infection and antigen expression is focal, requiring extensive examination for diagnosis; (3) extent of occult infection may indicate the extent of active infection in the organ as a whole; (4) most CMV hepatitis begins with infection of sinusoidal lining cells as a result of hematogenous spread from within the allograft or from systemic viremia; and (5) posttreatment biopsy specimens may be more sensitive than resolution of serum liver enzyme abnormalities in evaluating the success of ganciclovir therapy.

Macroregenerative nodules and hepatocellular carcinoma in forty-four sequential adult liver explants with cirrhosis

Macroregenerative nodules, also called nodules of adenomatous hyperplasia, have been well documented in Japan. Extensive studies support the hypothesis that in the Japanese population these lesions represent a possible pathway for hepatocarcinogenesis. However, reporting of these lesions in non-Japanese populations has so far been rare. We examined 44 sequential cirrhotic hepatectomy specimens from adult patients who underwent orthotopic liver transplantation at our institution. All livers were serially sectioned every 0.5 cm. Macroregenerative nodules were defined as regenerative nodules at least 1 cm in diameter. Forty-eight macroregenerative nodules were found in 11 livers (25% of livers). The antecedent diseases in these livers included hepatitis C (3), alcoholism (2), primary biliary cirrhosis (2) (one with iron overload), cryptogenic cirrhosis (2), hepatitis B (1) and alpha 1-antitrypsin deficiency (1). The macroregenerative nodules often differed from the surrounding nodular parenchyma in color, texture or the degree to which they bulged beyond the cut liver surface. Three livers contained grossly apparent hepatocellular carcinomas. Microscopically, macroregenerative nodules could be classified as those with (type 2) and without (type 1) dysplasia. Four livers had type 1 lesions, two had type 2 lesions and five had lesions of both types. We found 36 type 1 lesions in all and 12 type 2 lesions, 3 containing foci of microscopic carcinoma. All hepatocellular carcinomas arose in livers containing macroregenerative nodules (either type). Liver cell dysplasia, large-cell or small-cell, was observed in cirrhotic nodules of 27 livers. Microscopic or macroscopic hepatocellular carcinoma occurred in three livers with large-cell but not small-cell dysplasia and in one liver without dysplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatic histopathology in the acquired immunodeficiency syndrome

Involvement of the liver with the same opportunistic organisms and neoplasms affecting other organs has been recognized since the beginning of the AIDS epidemic. In this overview of hepatic histopathologic features in AIDS, we review the range of opportunistic infections and neoplasms accompanying HIV infection. Hepatic disease may result from viral, bacterial, protozoal, or fungal infection, or secondary to drugs and neoplasms. Liver involvement in AIDS usually reflects disseminated rather than primary disease. CMV and mycobacteria are the most common organisms in liver identified in biopsy and autopsy studies. A variety of nonspecific features, including steatosis, granulomas, and sinusoidal abnormalities may also be seen. HIV-1 itself was recently identified in the liver. Speculation regarding the significance of this finding has been discussed in this review. Hepatitis B, C, and D may also complicate the course of disease in patients with AIDS. Hepatitis B behaves differently in the population with AIDS than in immunocompetent patients. We concluded our review with a discussion of the present recommendations regarding the use of liver biopsies in these patients. This topic continues to be widely debated in the literature.

Detection of cytomegalovirus in lung allografts. Comparison of histologic and immunohistochemical findings

Although the histologic manifestation of cytomegalovirus (CMV) is usually characteristic intracellular inclusions and cytomegaly, some investigators, using immunohistochemical or in situ hybridization techniques, have demonstrated the presence of histologically occult infections in certain tissues. A series of lung biopsy specimens from pulmonary transplant recipients were studied using a monoclonal antibody (CCH2) to CMV early viral antigen and the results were compared with routine histologic findings. Occult infection could not be demonstrated in any of these cases. These results may reflect the relative sensitivity of the monoclonal antibody used in this study, although other possible factors are discussed. The results suggest that, in lung allograft biopsy specimens, immunohistochemical analysis using monoclonal antibody CCH2 is not likely to increase significantly the yield of positive cases compared with examination of multiple levels of hematoxylin-and-eosin-stained sections. Additional studies are needed to compare the sensitivity of monoclonal antibodies to CMV antigens using a variety of sampling techniques and clinical settings.