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Michael Torbenson

Publications and source records attributed to Michael Torbenson.

At least 19 recordsLinked to original sources

Use of T-cell antibodies for donor dosaging in a canine model of in utero hematopoietic stem cell transplantation.

AIM: Microchimerism following canine in utero hematopoietic stem cell transplantation (IUHSCT) development of T-cell dosing regimens. OBJECTIVE: To investigate the use of anti-T-cell antibodies for cell dosing of the donor graft in a canine model of IUHSCT. STUDY DESIGN: Canine IUHSCT was performed by ultrasound-guided intraperitoneal injection in days 35-38 of fetal canines with CD34(+) cells at doses of 4.5 x 10(8) to 1.3 x 10(9) cells/kg and T cells (CD3(+) CD5(+)) at doses of 8 x 10(6) to 8.8 x 10(8) cells/kg. Postnatal studies included tissue histology and polymerase chain reaction-based chimerism analysis. RESULTS: Term survival was 86-100%. Microchimerism (0-2%) was detected in five of eight recipients in multiple tissues. Histopathology revealed no evidence of graft-versus-host disease (GVHD). CONCLUSION: Canine IUHSCT is a useful model to investigate the role of donor T cells in engraftment and GVHD. IUHSCT at early gestational ages with high doses of donor T cells in the graft yields microchimerism in multiple tissues without GVHD.

Animals↗

Limited effectiveness of antiviral treatment for hepatitis C in an urban HIV clinic.

OBJECTIVE: To evaluate predictors and trends of referral for hepatitis C virus (HCV) care, clinic attendance and treatment in an urban HIV clinic. DESIGN AND METHODS: A retrospective cohort analysis in which 845 of 1318 co-infected adults who attended the Johns Hopkins HIV clinic between 1998 and 2003 after an on-site viral hepatitis clinic was opened, attended regularly (>/= 1 visit/year for >/= 2 years). Logistic regression was used to examine predictors of referral. RESULTS: A total of 277 (33%) of 845 were referred for HCV care. Independent predictors of referral included percentage elevated alanine aminotransferase levels [adjusted odds ratio (AOR) for 10% increase,1.16; 95% confidence interval (CI), 1.10-1.22] and CD4 cell count > 350 cells/microl (AOR, 3.20; 95% CI, 2.10-4.90), while injection drug use was a barrier to referral (AOR, 0.26; 95% CI, 0.11-0.64). Overall referral rate increased from < 1% in 1998 to 28% in 2003; however, even in 2003, 65% of those with CD4 cell count > 200 cells/microl were not referred. One hundred and eighty-five (67%) of 277 referred kept their appointment, of whom 32% failed to complete a pre-treatment evaluation. Of the remaining 125, only 69 (55%) were medically eligible for treatment, and 29 (42%) underwent HCV treatment. Ninety percent of 29 were infected with genotype 1 and 70% were African American; six (21%) achieved sustained virologic response (SVR). Only 0.7% of the full cohort achieved SVR. CONCLUSIONS: Although the potential for SVR and the recent marked increase in access to HCV care are encouraging, overall effectiveness of anti-HCV treatment in this urban, chiefly African American, HCV genotype 1 HIV clinic is extremely low. New therapies and treatment strategies are an urgent medical need.

Adult↗

Hepatitis C and hepatitis B nucleic acids are present in intrahepatic cholangiocarcinomas from the United States.

Intrahepatic cholangiocarcinomas (IHCs) are rare in the United States, but the prevalence is steadily increasing and risk factors are poorly understood. Tissues were obtained at the time of surgical resection, and 11 cases of IHC were retrospectively studied for the presence of hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA. Hemi-nested and real-time polymerase chain reaction assays were used to detect HBV DNA, and nested reverse transcriptase-polymerase chain reaction was used to detect HCV RNA. Genotypes were determined for both HBV and HCV. The cases were predominantly from women (10/11), with an average age at surgery of 63 years and an average tumor size of 6 cm. Three cases (27%) were positive for either HBV or HCV nucleic acids: HBV alone (n = 1), HCV alone (1), coinfection with HBV and HCV (1). Both HBV-positive cases were genotype A, and both HCV cases were genotype 1a. Hepatitis B and C viral copy numbers were low in all cases. Evidence for active HBV replication was found in both HBV-positive cases, as they were positive for covalently closed circular DNA. In this study, 27% of ICC cases contained HBV and/or HCV nucleic acids, suggesting an etiologic role for these viruses in some cases of IHC.

Adult↗

Progression of liver fibrosis among injection drug users with chronic hepatitis C.

Although most hepatitis C virus (HCV) infections are acquired by injection drug use, prospective data on the progression of liver fibrosis are sparse. Baseline liver biopsies were obtained (1996-1998) on a random sample of 210 out of 1667 HCV-positive injection drug users (IDUs). Subjects were followed biannually, with a second biopsy offered to those eligible. Paired biopsies were scored 0 to 6 (modified Ishak score), significant fibrosis was defined as score 3 or greater, and progression of fibrosis was defined as an increase 2 or more units or clinical evidence of end-stage liver disease. Predictive values of blood markers [FibroSURE, aspartate aminotransferase-to-platelet-ratio index (APRI) and alanine aminotransferase (ALT)] were assessed for detection of contemporaneous and future liver fibrosis. Among 119 prospectively followed IDUs, 96% were African American; 97% HCV genotype 1a/b; 27% HIV-infected, and median age was 42 years. Most (90.7%) did not have significant liver fibrosis at first biopsy. Although predictive value for detecting insignificant fibrosis at first biopsy was greater than 95% for FibroSURE, APRI, and ALT, specificities were 88.9%, 72.7%, and 72.7%, respectively. After 4.2 years median follow-up, 21% had progression of fibrosis, which was significantly associated with serum level of HCV RNA and ALT. No serological test had predictive value greater than 40% for contemporaneous or future significant fibrosis. Even initial biopsy result had only a 30.4% value for predicting future significant fibrosis. In conclusion, significant liver fibrosis and progression were detected in some, but not most, IDUs in this cohort. In this setting with low fibrosis prevalence, FibroSURE, ALT, and APRI tests predict insignificant fibrosis; however, further work is needed to find noninvasive markers of significant liver fibrosis.

Adult↗

Tuberculosis-associated haemophagocytic syndrome.

Haemophagocytic syndrome is a disorder characterised by fevers, lymphadenopathy, hepatosplenomegaly, cytopenias, and hyperferritinaemia due to dysregulated activation and proliferation of macrophages, leading to uncontrolled phagocytosis of platelets, erythrocytes, lymphocytes, and their haematopoietic precursors throughout the reticuloendothelial system. Primary or familial haemophagocytic syndrome appears to have a genetic aetiology, whereas secondary haemophagocytic syndrome may be associated with malignancy, autoimmune disease, or infection. Epstein-Barr virus is the most common infectious aetiology implicated in haemophagocytic syndrome, but the syndrome has been associated with a variety of other viral, bacterial, and parasitic pathogens. We describe a case of haemophagocytic syndrome associated with disseminated Mycobacterium tuberculosis. We review all cases of M tuberculosis-associated haemophagocytic syndrome reported in the English language literature and discuss important issues pertaining to the epidemiology, diagnosis, and management of this disease.

Abdominal Pain↗

Glycogenic hepatopathy: an underrecognized hepatic complication of diabetes mellitus.

Reported are the clinical and pathologic features of glycogenic hepatopathy, a pathologic overloading of hepatocytes with glycogen that is associated with poorly controlled diabetes mellitus. Fourteen cases were studied by stains, including hematoxylin and eosin, trichrome, periodic acid-Schiff, and periodic acid-Schiff with diastase. Ultrastructural analysis was performed in 2 cases. Medical records were reviewed for clinical presentations, laboratory findings, and clinical outcomes. The individuals ranged from 8 to 25 years of age. All had type I diabetes mellitus with poor glycemic control. The clinical presentations included hepatomegaly, abdominal pain, and elevated transaminases (range, 50-1600 IU/L). The transaminases were dramatically elevated in 3 cases to greater than 10 times the upper limit of normal. All biopsies showed diffusely pale staining hepatocytes on hematoxylin and eosin stains, with excessive glycogen accumulation demonstrated by periodic acid-Schiff stains. Ultrastructural examination revealed marked glycogen accumulation in the cytoplasm and nuclei. Most cases showed no evidence for fatty liver disease: steatosis was absent in 12 of 14 cases, simple steatosis was seen in 1 of 14 cases, and mild steatohepatitis was present in 1 of 14 cases. Mallory hyaline was absent in all cases, acidophil bodies were only rarely seen, and inflammation was absent or minimally present. Fibrosis was typically absent, with only 2 cases demonstrating focal mild fibrosis. Three patients had adequate follow-up and demonstrated improvement of liver enzyme levels with control of blood glucose. We conclude that glycogenic hepatopathy can cause hepatomegaly and significant transaminase elevations in individuals with type I diabetes mellitus. The pathology is distinct from steatohepatitis.

Adolescent↗

Glycogen pseudoground glass change in hepatocytes.

Ground glass cytoplasmic change in hepatocytes is typically associated with chronic hepatitis B infection. We report 12 cases of glycogen pseudoground glass change that closely mimics hepatitis B inclusions. Nine individuals were immunosuppressed secondary to liver or kidney transplant (N=3), bone marrow transplant (N=2), HIV infection (N=2), kidney dialysis (N=1), or chronic inflammatory bowel disease (N=1). Medication history was available in 10 individuals and all were on multiple medications (range 2 to 33). Histologically, the pseudoground glass change was identical to the ground glass change seen in chronic hepatitis B infection, with distinct, circumscribed, gray-glassy inclusions surrounded by a rim of cytoplasm. The background livers showed mild or no inflammation and mild or no fibrosis. All cases were negative for chronic hepatitis B infection. The pseudoground glass change was PAS positive and diastase sensitive. Electron microscopy of the inclusions showed glycogen in 3/3 cases. No evidence for viral particles or significant endoplasmic reticulum proliferation was seen. Three cases had follow-up biopsies (1, 1, and 36 mo), and the pseudoground glass was persistent in 2 cases and showed partial resolution in 1 case (1 mo biopsy interval). We conclude that glycogen pseudoground glass change is typically seen in immunosuppressed individuals on numerous medications. The changes are generally seen in the background of mild chronic hepatitis with mild or no fibrosis. Glycogen pseudoground glass change can resolve, but may also persist for years.

Adult↗

Atrophic autoimmune pangastritis: A distinctive form of antral and fundic gastritis associated with systemic autoimmune disease.

The 2 major recognized forms of atrophic gastritis are autoimmune and environmental atrophic gastritis. These differ in their topographical distribution in the stomach, histologic features, and etiology. Autoimmune atrophic gastritis results from immune-mediated destruction of specialized oxyntic glands, is restricted to the body and fundus, and shows characteristic neuroendocrine hyperplasia. Environmental atrophic gastritis is associated with long-standing Helicobacter pylori infection and preferentially involves antrum and transition zone mucosa. In this study, we describe a distinctive form of atrophic gastritis that differs markedly from both of these classic variants. This gastritis is characterized by: (1) intense mucosal inflammatory infiltrates, persisting even into the phase of severe glandular atrophy, (2) pangastric distribution with diffuse involvement of both body and antrum, (3) lack of association with H. pylori, and (4) lack of neuroendocrine hyperplasia. The 8 patients presented ranged from 1 to 75 years and showed a slight female predominance (5F:3M). All had systemic autoimmune and/or connective tissue diseases including autoimmune enterocolitis (4 cases), systemic lupus erythematosus, refractory sprue, autoimmune hemolytic anemia, and disabling fibromyalgia. Positive serum autoimmune markers were documented in 7 of 8 (87%) patients, but serologies for antiparietal cell and anti-intrinsic factor antibodies were undertaken in only 1 patient each and were negative. We propose that the distinctive histology of this form of atrophic pangastritis and its association with systemic autoimmune disease suggests an autoimmune process directed against multiple cell lineages in the stomach. The development of multifocal low-grade dysplasia in 1 patient, a 19-year-old woman, suggests that this condition might have neoplastic potential.

Adolescent↗

Hepatic steatosis and antiretroviral drug use among adults coinfected with HIV and hepatitis C virus.

OBJECTIVE: To ascertain the prevalence and severity of hepatic steatosis among patients coinfected with HIV and hepatitis C virus (HCV) who had been taking antiretroviral therapy (ART); to investigate if steatosis is associated with more advanced liver disease, and to identify factors that might contribute to the process. METHODS: Steatosis was assessed among a randomly selected subset of HIV-HCV-coinfected patients who had received at least 2 years of ART in a cohort study at the Johns Hopkins University HIV clinic. Liver histology was evaluated by a single pathologist. The primary outcome measure was the hepatic steatosis grade, which was classified on a 5 point scale: 0, none; 1, steatosis involving < 5% of hepatocytes; 2, 5-29%; 3, 30-60%; 4 > 60%. RESULTS: Liver histology was assessed in 112 patients, 74% of whom were taking ART at the time of biopsy. The median cumulative exposure to nucleoside reverse transcriptase inhibitors and protease inhibitors was 5.8 and 3.7 years, respectively. No steatosis was detected in 60%; grades 2-4 steatosis was recognized in 18%. In multivariate analysis, steatosis was independently associated with Caucasian race, weight > 86 kg, hyperglycemia, and stavudine use. Patients with steatosis also were more likely to have greater hepatic fibrosis (P = 0.02) and necroinflammatory activity (P = 0.005). CONCLUSIONS: Steatosis was observed in 40% of HIV-HCV-coinfected patients with extensive ART exposure and was associated with more severe HCV-related liver disease. Metabolic abnormalities (excess weight and hyperglycemia) and stavudine use were modifiable risk factors for steatosis in this population.

Aged↗

The effect of antiretroviral therapy on liver disease among adults with HIV and hepatitis C coinfection.

In the era of antiretroviral therapy (ART), liver disease has emerged as an important cause of death among persons with human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfection. The objective of this study was to estimate the burden of liver disease and evaluate determinants of liver fibrosis and necroinflammatory activity among HIV/HCV coinfected patients receiving ART. We studied 112 randomly selected and 98 referred HCV-infected patients undergoing care in the Johns Hopkins University HIV clinic. Liver disease was characterized clinically and histologically. Of the 210 individuals studied--64% of whom had received ART within 2 years of liver disease assessment--33% had no fibrosis (F0), and 26% had bridging fibrosis or cirrhosis (> or =F3). The median necroinflammatory activity score was 3 (range, 0-9 of 18). ART was not associated with fibrosis; however, significantly less hepatic necroinflammatory activity was observed among persons who had received highly active antiretroviral therapy longer (P = .02) and more effectively (defined by HIV RNA suppression; P < .01). Twelve percent of individuals had previous ART-associated liver enzyme elevations (grades 3-4), but liver fibrosis was not more severe if the liver enzyme elevation resolved. On the other hand, liver fibrosis was more severe in persons with persistent liver enzyme elevations (grades 1-4). In conclusion, despite widespread exposure to ART and documented instances of ART-related hepatitis, we found no evidence that ART caused serious histological liver disease. Recognition of bridging fibrosis and cirrhosis in some but not most patients underscores the importance of identifying and treating liver disease in HIV/HCV coinfected persons.

Adult↗

Hepatic angiomyolipoma and hepatic stellate cells share a similar gene expression profile.

BACKGROUND AND AIMS: Angiomyolipomas (AMLs) of the liver are rare neoplasms composed of large epithelioid cells with intermixed fat and blood vessels. Hepatic AMLs have no clear normal-cell counterpart in the liver. However, AMLs and stellate cells both are positive for neural crest-derived markers including HMB-45 antigen. METHODS: To further explore the similarities between hepatic AMLs and stellate cells, gene expression of a hepatic AML was studied by cDNA microarray. Real-time polymerase chain reaction was used to confirm gene expression. Hepatic stellate cells can be quiescent, activated, or have a myofibroblastic phenotype depending on their state of activation. Expression of known markers of activated stellate cells was compared between the AML, activated primary mouse stellate cells, and stellate cell lines with activated and myofibroblastic phenotypes. Next, 5 novel genes from the AML were selected because they were not previously known to be markers of stellate cells and mRNA expression measured in the activated mouse stellate cells and in myofibroblastic stellate cell lines. Finally, expression levels of 10 novel genes were determined in 5 cirrhotic and 5 noncirrhotic human livers. RESULTS: Overexpression of known markers of activated stellate cells including transforming growth factor beta (TGF- beta ), smooth muscle actin, and collagen was found in the hepatic AML. Three of 5 novel markers that were identified in the AML, RRAD (Ras-related associated with diabetes), CTSK (cathepsin K), and NIBAN were also found to be overexpressed in activated stellate cells compared with quiescent or myofibroblastic stellate cells. In addition, 9 of 10 novel genes overexpressed in AML were also overexpressed in cirrhotic human livers versus noncirrhotic livers. CONCLUSIONS: Hepatic AMLs share a similar gene expression profile and may differentiate toward activated stellate cells.

Angiomyolipoma↗

Survivin overexpression in hepatocellular carcinoma is associated with p53 dysregulation.

BACKGROUND: Survivin is a recently described anti-apoptotic protein that is suppressed by wild-type p53 and is overexpressed in 41-70% of hepatocellular carcinomas from Asia. Two alternatively spliced transcripts have also been described: anti-apoptotic survivin-DeltaEx3 and non-anti-apoptotic survivin-2B. Survivin splice variant expression has not been studied in HCC, and little is known about survivin expression in hepatocellular carcinomas arising in other parts of the world, where risk factors are often different than they are in Asia. AIM OF THE STUDY: We studied survivin mRNA and protein expression in a United States cohort of hepatocellular carcinomas and correlated the findings with p53 immunopositivity. METHODS: RT-PCR was performed for survivin, survivin-2B, and survivin-DeltaEx3 in 20 HCCs and one intrahepatic cholangiocarcinoma. Expression levels of total survivin were evaluated with real-time PCR. Protein expression was examined by immunohistochemistry. RESULTS: Survivin was the major transcript, and all transcripts were present in all normal and neoplastic tissues; 11/20 (55%) HCCs and the one cholangiocarcinoma showed twofold or greater overexpression of survivin. Next, we examined survivin and p53 protein expression by immunohistochemistry on a separate series of 79 HCC, 13 fibrolamellar carcinomas, and 15 hepatic adenomas; 14/79 (17%) HCC, but none of the fibrolamellar carcinomas or hepatic adenomas, showed survivin protein overexpression, and 25/79 HCC (32%) showed abnormal nuclear accumulation of p53, which correlated with increased survivin expression. CONCLUSIONS: All three survivin transcripts are present in normal liver and HCC. Survivin is the dominant transcript in HCC and is overexpressed in 55% of cases. Survivin protein overexpression is associated with aberrant p53 nuclear positivity.

Adult↗

mTOR and P70 S6 kinase expression in primary liver neoplasms.

PURPOSE: mTOR and P70 S6 kinase (S6K) play a key role in regulating protein translation. The role of mTOR and S6K in hepatocellular carcinoma has not been investigated, but this pathway is of particular interest because an effective inhibitor, rapamycin, is available. This study was undertaken to determine the prevalence and clinicopathological correlates of mTOR pathway activation in hepatocellular carcinoma and to determine whether rapamycin inhibits the pathway in cell culture. EXPERIMENTAL DESIGN: Total and phosphorylated mTOR and S6K protein expression were studied by immunohistochemistry in hepatocellular carcinomas (n = 73), fibrolamellar carcinomas (n = 13), and hepatic adenomas (n = 15). Results were correlated with tumor growth pattern as defined by the WHO (trabecular, pseudoglandular/acinar, compact, and scirrhous), tumor size, Ki-67 proliferation index, and the modified Edmondson nuclear grade, which has a scale of 1 to 4. HepG2 and Hep3B cell lines were treated with rapamycin to see the effect on proliferation and S6K phosphorylation. RESULTS: Increased expression of total mTOR was seen in 5% of hepatocellular carcinoma, whereas overexpression of phospho-mTOR was evident in 15% of hepatocellular carcinoma. Phospho-mTOR positivity correlated with increased expression of total S6K, which was found in 45% of cases. Total S6K overexpression was positively correlated with tumor nuclear grade, inversely with tumor size, and was unassociated with the proliferation index or WHO growth pattern. Rapamycin treatment of HepG2 and Hep3B cell lines markedly inhibited cell proliferation and reduced S6K phosphorylation in both cell lines. CONCLUSIONS: The mTOR pathway is activated in a subset of hepatocellular carcinoma. Rapamycin can inhibit proliferation of neoplastic hepatocytes in cell culture.

Adenoma↗

Cytopathologic grading of hepatocellular carcinoma on fine-needle aspiration.

BACKGROUND: Hepatocellular carcinoma (HCC) is routinely graded histopathologically using a modified Edmondson system (ES). The cytologic grading of HCC has been used predominantly as an adjunct in differential diagnoses (i.e., to help distinguish HCC from other tumors as well as nonneoplastic lesions). However, there are unanswered questions regarding the reliability of the cytologic grading of HCC and its correlation with histologic follow-up. METHODS: A total of 106 cases of HCC were identified in the authors' cytopathology files from 1977 to the present. Of these cases, 64 had either a core needle or excisional biopsy sample that was judged to be adequate for histologic grading. From each case smears were graded independently in a blinded fashion by two cytopathologists, and tissue slides were graded by a liver pathologist. The cytopathologists' grading was then adjudicated by considering the histologic diagnosis as the "truth standard". Finally, after the scores were calculated, a statistical analysis was performed to ascertain the accuracy of the cytopathologic grading. RESULTS: The sensitivity for accurate grading was found to be highest for well differentiated (WD) lesions; the specificity was found to be highest for poorly differentiated (PD) HCC for both cytopathologists. Interobserver agreement was highest for WD HCC. WD HCC displayed cohesive fragments, often associated with characteristic vascular/endothelial patterns. In addition, moderately differentiated (MD) HCC demonstrated numerous single cells and atypical naked nuclei, usually with prominent nucleoli. PD HCC displayed loose nests and three-dimensional fragments (often gland-like), pleomorphism, macronucleoli, and focal necrosis. CONCLUSIONS: In the authors' experience, the three-tier cytologic grading of HCC was found to be only moderately accurate. The accuracy of cytologic grading was reported to be high for WD/PD HCC and low for MD HCC. The architectural criteria appear to be more useful for WD HCC, whereas marked cellular pleomorphism is specific for PD HCC. The authors propose that a two-tier grading system may be more useful, given the recent studies of HCC recurrence.

Biopsy, Fine-Needle↗

High prevalence of occult hepatitis B in Baltimore injection drug users.

Occult hepatitis B is defined by the presence of hepatitis B virus (HBV) DNA in a serum or liver in the absence of hepatitis B surface antigen (HBsAg). The prevalence and clinical correlates of occult hepatitis B remain incompletely defined. A cross-sectional study was performed to determine the prevalence of occult hepatitis B in a high-risk cohort composed of 188 injection drug users in Baltimore, Maryland. All individuals had chronic hepatitis C viral infections confirmed by RNA detection and liver biopsy. Serologic assays for HBsAg and core antibody (HBcAb) were performed. Serum HBV DNA was detected using the COBAS HBV AMPLICOR monitor assay (lower limit of detection, 200 HBV copies per milliliter) and a semi-nested polymerase chain reaction (PCR) assay (lower limit of detection, 15 HBV copies per milliliter). Although almost all individuals (96%) were anti-HBC positive, only 8 of 188 (4%) were HBsAg positive. Occult hepatitis B was not identified using the COBAS assay, but was found in 81 of 180 (45%) of individuals using semi-nested PCR. Of the 8 HBsAg positive individuals, HBV DNA was found in 1/8 using the COBAS assay and 6/8 using the nested PCR assay. Overall, liver disease was mild, with a median serum alanine aminotransferase (ALT) of 38 IU/L, median activity grade of 3/18, and median fibrosis stage of 1/6. No association was found between the serum AST (aspartate aminotransferase), activity grade, or stage of liver disease and the presence of occult hepatitis B. Serum ALT levels were slightly higher in patients without occult hepatitis B (46 vs. 35 IU/L), and the median years since first injection drug use was somewhat longer in those without occult hepatitis B (24 vs. 20 years). In conclusion, although further research is needed to assess its clinical significance, there is a high prevalence of occult HBV infection in this cohort of HCV-infected injection drug users.

Adult↗

Leiomyosarcoma of the breast: a pathologic and comparative genomic hybridization study of two cases.

Leiomyosarcoma is an extremely rare form of primary breast sarcoma. We present the pathologic and genetic findings of two cases of leiomyosarcoma of the breast. The patients were 44 and 52 years of age and they presented with circumscribed masses of 3.0 and 4.5 cm, (greatest dimension) respectively. Microscopically, the two tumors showed diffuse proliferation of spindle cells with oval and blunt-ended nuclei arranged in short fascicles or bundles. There was moderate cytologic atypia in both cases, and 6 and 12 mitotic figures per 10 high power fields, respectively. No epithelial component was identified. The tumor cells were strongly immunoreactive for markers of smooth-muscle differentiation, including desmin, muscle-specific actin, and smooth-muscle actin. Comparative genomic hybridization analysis showed losses of 10q (two of two cases), 13q (two of two cases), 17p (one of two cases), and gains of 1q (one of two cases) and 17p (one of two cases). The patterns of chromosomal imbalances identified in leiomyosarcoma of the breast are similar to those reported in leiomyosarcoma of soft tissue and uterus and are different from those reported for leiomyoma, indicating that these alterations may be important for development of malignant smooth-muscle tumors regardless of site or organ of origin.

Adult↗

FHIT mRNA and protein expression in hepatocellular carcinoma.

Loss of fragile histidine triad (FHIT) gene expression is seen in approximately 50% of hepatocellular carcinomas in China. However, little information is available on FHIT expression in hepatocellular carcinoma in the United States, where carcinogen exposure is generally lower. Investigations of FHIT mRNA in hepatocellular neoplasms and paired non-neoplastic tissues demonstrated normal-sized FHIT transcripts in all non-neoplastic tissues and in all neoplasms including 11 hepatocellular carcinomas, two fibrolamellar carcinomas, and four benign proliferative lesions. In addition, all but one malignant and all benign neoplasms showed aberrant smaller transcripts. The smaller aberrant transcripts were overexpressed in 6/11 hepatocellular carcinomas and 1/2 fibrolamellar carcinomas. An additional 79 hepatocellular carcinomas, 12 fibrolamellar carcinomas and 15 hepatic adenomas were examined for FHIT expression by immunohistochemistry. No loss of immunostaining was seen in 67/79 (85%) of hepatocellular carcinomas, while a moderate or marked decrease was seen in 12/79 (15%). Fibrolamellar carcinomas and hepatic adenomas showed no loss of FHIT expression. In conclusion, hepatocellular carcinomas retained expression of normal FHIT mRNA transcripts, but also showed universal expression of smaller sized aberrant transcripts and commonly overexpressed these aberrant transcripts. Loss of FHIT protein expression is relatively uncommon in this cohort from the United States, where exposure to hepatic carcinogens is generally low.

Acid Anhydride Hydrolases↗

Concurrent evaluation of p53, beta-catenin, and alpha-fetoprotein expression in human hepatocellular carcinoma.

Recent models suggest that hepatocellular carcinoma (HCC) develops through several independent pathways marked by key mutations in the beta-catenin or p53 gene. An additional pathway potentially is marked by aberrant expression of a-fetoprotein (AFP). To see whether these potential markers are expressed independently, we immunostained sequential sections from 55 HCCs. Of the cases, 30 (55%) were positive for 1 or more proteins: AFP, 19 cases (35%); p53, 12 cases (22%); and beta-catenin, 9 cases (16%). Seven tumors (13%) were positive for more than 1 protein, with 4 of 7 positive in the same area of tumor and 3 of 7 positive in different areas of the carcinomas. By statistical analysis, expression of the markers was independent of one another and of tumor size. Concurrent evaluation of p53, beta-catenin, and AFP protein expression showed no associations, supporting models in which these proteins might serve as markers of independent pathways in the development of HCC.

Adult↗